jdk8-mips64-public/hotspot: src/share/vm/code/nmethod.cpp@5cece4584b8e (annotated)

src/share/vm/code/nmethod.cpp@5cece4584b8e (annotated)

src/share/vm/code/nmethod.cpp

Thu, 12 Nov 2015 09:53:17 +0100

author: stefank
date: Thu, 12 Nov 2015 09:53:17 +0100
changeset 8185: 5cece4584b8e
parent 8075: be740540f60c
child 8604: 04d83ba48607
child 8647: 0b611970fa8b
child 8964: 77e13f15e396
permissions: -rw-r--r--

8058563: InstanceKlass::_dependencies list isn't cleared from empty nmethodBucket entries
Reviewed-by: mgerdin, vlivanov

 /*
  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "code/codeCache.hpp"
 #include "code/compiledIC.hpp"
 #include "code/dependencies.hpp"
 #include "code/nmethod.hpp"
 #include "code/scopeDesc.hpp"
 #include "compiler/abstractCompiler.hpp"
 #include "compiler/compileBroker.hpp"
 #include "compiler/compileLog.hpp"
 #include "compiler/compilerOracle.hpp"
 #include "compiler/disassembler.hpp"
 #include "interpreter/bytecode.hpp"
 #include "oops/methodData.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
 #include "prims/jvmtiImpl.hpp"
 #include "runtime/orderAccess.inline.hpp"
 #include "runtime/sharedRuntime.hpp"
 #include "runtime/sweeper.hpp"
 #include "utilities/dtrace.hpp"
 #include "utilities/events.hpp"
 #include "utilities/xmlstream.hpp"
 #ifdef SHARK
 #include "shark/sharkCompiler.hpp"
 #endif
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 unsigned char nmethod::_global_unloading_clock = 0;
 #ifdef DTRACE_ENABLED
 // Only bother with this argument setup if dtrace is available
 #ifndef USDT2
 HS_DTRACE_PROBE_DECL8(hotspot, compiled__method__load,
   const char*, int, const char*, int, const char*, int, void*, size_t);
 HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
   char*, int, char*, int, char*, int);
 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
   {                                                                       \
     Method* m = (method);                                                 \
     if (m != NULL) {                                                      \
       Symbol* klass_name = m->klass_name();                               \
       Symbol* name = m->name();                                           \
       Symbol* signature = m->signature();                                 \
       HS_DTRACE_PROBE6(hotspot, compiled__method__unload,                 \
         klass_name->bytes(), klass_name->utf8_length(),                   \
         name->bytes(), name->utf8_length(),                               \
         signature->bytes(), signature->utf8_length());                    \
     }                                                                     \
   }
 #else /* USDT2 */
 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
   {                                                                       \
     Method* m = (method);                                                 \
     if (m != NULL) {                                                      \
       Symbol* klass_name = m->klass_name();                               \
       Symbol* name = m->name();                                           \
       Symbol* signature = m->signature();                                 \
       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
         (char *) name->bytes(), name->utf8_length(),                               \
         (char *) signature->bytes(), signature->utf8_length());                    \
     }                                                                     \
   }
 #endif /* USDT2 */
 #else //  ndef DTRACE_ENABLED
 #define DTRACE_METHOD_UNLOAD_PROBE(method)
 #endif
 bool nmethod::is_compiled_by_c1() const {
   if (compiler() == NULL) {
     return false;
   }
   return compiler()->is_c1();
 }
 bool nmethod::is_compiled_by_c2() const {
   if (compiler() == NULL) {
     return false;
   }
   return compiler()->is_c2();
 }
 bool nmethod::is_compiled_by_shark() const {
   if (compiler() == NULL) {
     return false;
   }
   return compiler()->is_shark();
 }
 //---------------------------------------------------------------------------------
 // NMethod statistics
 // They are printed under various flags, including:
 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
 // (In the latter two cases, they like other stats are printed to the log only.)
 #ifndef PRODUCT
 // These variables are put into one block to reduce relocations
 // and make it simpler to print from the debugger.
 static
 struct nmethod_stats_struct {
   int nmethod_count;
   int total_size;
   int relocation_size;
   int consts_size;
   int insts_size;
   int stub_size;
   int scopes_data_size;
   int scopes_pcs_size;
   int dependencies_size;
   int handler_table_size;
   int nul_chk_table_size;
   int oops_size;
   void note_nmethod(nmethod* nm) {
     nmethod_count += 1;
     total_size          += nm->size();
     relocation_size     += nm->relocation_size();
     consts_size         += nm->consts_size();
     insts_size          += nm->insts_size();
     stub_size           += nm->stub_size();
     oops_size           += nm->oops_size();
     scopes_data_size    += nm->scopes_data_size();
     scopes_pcs_size     += nm->scopes_pcs_size();
     dependencies_size   += nm->dependencies_size();
     handler_table_size  += nm->handler_table_size();
     nul_chk_table_size  += nm->nul_chk_table_size();
   }
   void print_nmethod_stats() {
     if (nmethod_count == 0)  return;
     tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
   }
   int native_nmethod_count;
   int native_total_size;
   int native_relocation_size;
   int native_insts_size;
   int native_oops_size;
   void note_native_nmethod(nmethod* nm) {
     native_nmethod_count += 1;
     native_total_size       += nm->size();
     native_relocation_size  += nm->relocation_size();
     native_insts_size       += nm->insts_size();
     native_oops_size        += nm->oops_size();
   }
   void print_native_nmethod_stats() {
     if (native_nmethod_count == 0)  return;
     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
   }
   int pc_desc_resets;   // number of resets (= number of caches)
   int pc_desc_queries;  // queries to nmethod::find_pc_desc
   int pc_desc_approx;   // number of those which have approximate true
   int pc_desc_repeats;  // number of _pc_descs[0] hits
   int pc_desc_hits;     // number of LRU cache hits
   int pc_desc_tests;    // total number of PcDesc examinations
   int pc_desc_searches; // total number of quasi-binary search steps
   int pc_desc_adds;     // number of LUR cache insertions
   void print_pc_stats() {
     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
                   pc_desc_queries,
                   (double)(pc_desc_tests + pc_desc_searches)
                   / pc_desc_queries);
     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
                   pc_desc_resets,
                   pc_desc_queries, pc_desc_approx,
                   pc_desc_repeats, pc_desc_hits,
                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
   }
 } nmethod_stats;
 #endif //PRODUCT
 //---------------------------------------------------------------------------------
 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
   assert(pc != NULL, "Must be non null");
   assert(exception.not_null(), "Must be non null");
   assert(handler != NULL, "Must be non null");
   _count = 0;
   _exception_type = exception->klass();
   _next = NULL;
   add_address_and_handler(pc,handler);
 }
 address ExceptionCache::match(Handle exception, address pc) {
   assert(pc != NULL,"Must be non null");
   assert(exception.not_null(),"Must be non null");
   if (exception->klass() == exception_type()) {
     return (test_address(pc));
   }
   return NULL;
 }
 bool ExceptionCache::match_exception_with_space(Handle exception) {
   assert(exception.not_null(),"Must be non null");
   if (exception->klass() == exception_type() && count() < cache_size) {
     return true;
   }
   return false;
 }
 address ExceptionCache::test_address(address addr) {
   for (int i=0; i<count(); i++) {
     if (pc_at(i) == addr) {
       return handler_at(i);
     }
   }
   return NULL;
 }
 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
   if (test_address(addr) == handler) return true;
   if (count() < cache_size) {
     set_pc_at(count(),addr);
     set_handler_at(count(), handler);
     increment_count();
     return true;
   }
   return false;
 }
 // private method for handling exception cache
 // These methods are private, and used to manipulate the exception cache
 // directly.
 ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
   ExceptionCache* ec = exception_cache();
   while (ec != NULL) {
     if (ec->match_exception_with_space(exception)) {
       return ec;
     }
     ec = ec->next();
   }
   return NULL;
 }
 //-----------------------------------------------------------------------------
 // Helper used by both find_pc_desc methods.
 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
   NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
   if (!approximate)
     return pc->pc_offset() == pc_offset;
   else
     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 }
 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
   if (initial_pc_desc == NULL) {
     _pc_descs[0] = NULL; // native method; no PcDescs at all
     return;
   }
   NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
   // reset the cache by filling it with benign (non-null) values
   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
   for (int i = 0; i < cache_size; i++)
     _pc_descs[i] = initial_pc_desc;
 }
 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
   NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
   NOT_PRODUCT(if (approximate) ++nmethod_stats.pc_desc_approx);
   // Note: one might think that caching the most recently
   // read value separately would be a win, but one would be
   // wrong.  When many threads are updating it, the cache
   // line it's in would bounce between caches, negating
   // any benefit.
   // In order to prevent race conditions do not load cache elements
   // repeatedly, but use a local copy:
   PcDesc* res;
   // Step one:  Check the most recently added value.
   res = _pc_descs[0];
   if (res == NULL) return NULL;  // native method; no PcDescs at all
   if (match_desc(res, pc_offset, approximate)) {
     NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
     return res;
   }
   // Step two:  Check the rest of the LRU cache.
   for (int i = 1; i < cache_size; ++i) {
     res = _pc_descs[i];
     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
     if (match_desc(res, pc_offset, approximate)) {
       NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
       return res;
     }
   }
   // Report failure.
   return NULL;
 }
 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
   NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
   // Update the LRU cache by shifting pc_desc forward.
   for (int i = 0; i < cache_size; i++)  {
     PcDesc* next = _pc_descs[i];
     _pc_descs[i] = pc_desc;
     pc_desc = next;
   }
 }
 // adjust pcs_size so that it is a multiple of both oopSize and
 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 // of oopSize, then 2*sizeof(PcDesc) is)
 static int adjust_pcs_size(int pcs_size) {
   int nsize = round_to(pcs_size,   oopSize);
   if ((nsize % sizeof(PcDesc)) != 0) {
     nsize = pcs_size + sizeof(PcDesc);
   }
   assert((nsize % oopSize) == 0, "correct alignment");
   return nsize;
 }
 //-----------------------------------------------------------------------------
 void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
   assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
   assert(new_entry != NULL,"Must be non null");
   assert(new_entry->next() == NULL, "Must be null");
   if (exception_cache() != NULL) {
     new_entry->set_next(exception_cache());
   }
   set_exception_cache(new_entry);
 }
 void nmethod::clean_exception_cache(BoolObjectClosure* is_alive) {
   ExceptionCache* prev = NULL;
   ExceptionCache* curr = exception_cache();
   while (curr != NULL) {
     ExceptionCache* next = curr->next();
     Klass* ex_klass = curr->exception_type();
     if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) {
       if (prev == NULL) {
         set_exception_cache(next);
       } else {
         prev->set_next(next);
       }
       delete curr;
       // prev stays the same.
     } else {
       prev = curr;
     }
     curr = next;
   }
 }
 // public method for accessing the exception cache
 // These are the public access methods.
 address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
   // We never grab a lock to read the exception cache, so we may
   // have false negatives. This is okay, as it can only happen during
   // the first few exception lookups for a given nmethod.
   ExceptionCache* ec = exception_cache();
   while (ec != NULL) {
     address ret_val;
     if ((ret_val = ec->match(exception,pc)) != NULL) {
       return ret_val;
     }
     ec = ec->next();
   }
   return NULL;
 }
 void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
   // There are potential race conditions during exception cache updates, so we
   // must own the ExceptionCache_lock before doing ANY modifications. Because
   // we don't lock during reads, it is possible to have several threads attempt
   // to update the cache with the same data. We need to check for already inserted
   // copies of the current data before adding it.
   MutexLocker ml(ExceptionCache_lock);
   ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
   if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
     target_entry = new ExceptionCache(exception,pc,handler);
     add_exception_cache_entry(target_entry);
   }
 }
 //-------------end of code for ExceptionCache--------------
 int nmethod::total_size() const {
   return
     consts_size()        +
     insts_size()         +
     stub_size()          +
     scopes_data_size()   +
     scopes_pcs_size()    +
     handler_table_size() +
     nul_chk_table_size();
 }
 const char* nmethod::compile_kind() const {
   if (is_osr_method())     return "osr";
   if (method() != NULL && is_native_method())  return "c2n";
   return NULL;
 }
 // Fill in default values for various flag fields
 void nmethod::init_defaults() {
   _state                      = in_use;
   _unloading_clock            = 0;
   _marked_for_reclamation     = 0;
   _has_flushed_dependencies   = 0;
   _has_unsafe_access          = 0;
   _has_method_handle_invokes  = 0;
   _lazy_critical_native       = 0;
   _has_wide_vectors           = 0;
   _marked_for_deoptimization  = 0;
   _lock_count                 = 0;
   _stack_traversal_mark       = 0;
   _unload_reported            = false;           // jvmti state
 #ifdef ASSERT
   _oops_are_stale             = false;
 #endif
   _oops_do_mark_link       = NULL;
   _jmethod_id              = NULL;
   _osr_link                = NULL;
   if (UseG1GC) {
     _unloading_next        = NULL;
   } else {
     _scavenge_root_link    = NULL;
   }
   _scavenge_root_state     = 0;
   _compiler                = NULL;
 #if INCLUDE_RTM_OPT
   _rtm_state               = NoRTM;
 #endif
 #ifdef HAVE_DTRACE_H
   _trap_offset             = 0;
 #endif // def HAVE_DTRACE_H
 }
 nmethod* nmethod::new_native_nmethod(methodHandle method,
   int compile_id,
   CodeBuffer *code_buffer,
   int vep_offset,
   int frame_complete,
   int frame_size,
   ByteSize basic_lock_owner_sp_offset,
   ByteSize basic_lock_sp_offset,
   OopMapSet* oop_maps) {
   code_buffer->finalize_oop_references(method);
   // create nmethod
   nmethod* nm = NULL;
   {
     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
     CodeOffsets offsets;
     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
     nm = new (native_nmethod_size) nmethod(method(), native_nmethod_size,
                                             compile_id, &offsets,
                                             code_buffer, frame_size,
                                             basic_lock_owner_sp_offset,
                                             basic_lock_sp_offset, oop_maps);
     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
     if (PrintAssembly && nm != NULL) {
       Disassembler::decode(nm);
     }
   }
   // verify nmethod
   debug_only(if (nm) nm->verify();) // might block
   if (nm != NULL) {
     nm->log_new_nmethod();
   }
   return nm;
 }
 #ifdef HAVE_DTRACE_H
 nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
                                      CodeBuffer *code_buffer,
                                      int vep_offset,
                                      int trap_offset,
                                      int frame_complete,
                                      int frame_size) {
   code_buffer->finalize_oop_references(method);
   // create nmethod
   nmethod* nm = NULL;
   {
     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
     CodeOffsets offsets;
     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
     offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
     nm = new (nmethod_size) nmethod(method(), nmethod_size,
                                     &offsets, code_buffer, frame_size);
     NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
     if (PrintAssembly && nm != NULL) {
       Disassembler::decode(nm);
     }
   }
   // verify nmethod
   debug_only(if (nm) nm->verify();) // might block
   if (nm != NULL) {
     nm->log_new_nmethod();
   }
   return nm;
 }
 #endif // def HAVE_DTRACE_H
 nmethod* nmethod::new_nmethod(methodHandle method,
   int compile_id,
   int entry_bci,
   CodeOffsets* offsets,
   int orig_pc_offset,
   DebugInformationRecorder* debug_info,
   Dependencies* dependencies,
   CodeBuffer* code_buffer, int frame_size,
   OopMapSet* oop_maps,
   ExceptionHandlerTable* handler_table,
   ImplicitExceptionTable* nul_chk_table,
   AbstractCompiler* compiler,
   int comp_level
 )
 {
   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   code_buffer->finalize_oop_references(method);
   // create nmethod
   nmethod* nm = NULL;
   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
     int nmethod_size =
       allocation_size(code_buffer, sizeof(nmethod))
       + adjust_pcs_size(debug_info->pcs_size())
       + round_to(dependencies->size_in_bytes() , oopSize)
       + round_to(handler_table->size_in_bytes(), oopSize)
       + round_to(nul_chk_table->size_in_bytes(), oopSize)
       + round_to(debug_info->data_size()       , oopSize);
     nm = new (nmethod_size)
     nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
             oop_maps,
             handler_table,
             nul_chk_table,
             compiler,
             comp_level);
     if (nm != NULL) {
       // To make dependency checking during class loading fast, record
       // the nmethod dependencies in the classes it is dependent on.
       // This allows the dependency checking code to simply walk the
       // class hierarchy above the loaded class, checking only nmethods
       // which are dependent on those classes.  The slow way is to
       // check every nmethod for dependencies which makes it linear in
       // the number of methods compiled.  For applications with a lot
       // classes the slow way is too slow.
       for (Dependencies::DepStream deps(nm); deps.next(); ) {
         Klass* klass = deps.context_type();
         if (klass == NULL) {
           continue;  // ignore things like evol_method
         }
         // record this nmethod as dependent on this klass
         InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
       }
       NOT_PRODUCT(nmethod_stats.note_nmethod(nm));
       if (PrintAssembly || CompilerOracle::has_option_string(method, "PrintAssembly")) {
         Disassembler::decode(nm);
       }
     }
   }
   // Do verification and logging outside CodeCache_lock.
   if (nm != NULL) {
     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
     DEBUG_ONLY(nm->verify();)
     nm->log_new_nmethod();
   }
   return nm;
 }
 // For native wrappers
 nmethod::nmethod(
   Method* method,
   int nmethod_size,
   int compile_id,
   CodeOffsets* offsets,
   CodeBuffer* code_buffer,
   int frame_size,
   ByteSize basic_lock_owner_sp_offset,
   ByteSize basic_lock_sp_offset,
   OopMapSet* oop_maps )
   : CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 {
   {
     debug_only(No_Safepoint_Verifier nsv;)
     assert_locked_or_safepoint(CodeCache_lock);
     init_defaults();
     _method                  = method;
     _entry_bci               = InvocationEntryBci;
     // We have no exception handler or deopt handler make the
     // values something that will never match a pc like the nmethod vtable entry
     _exception_offset        = 0;
     _deoptimize_offset       = 0;
     _deoptimize_mh_offset    = 0;
     _orig_pc_offset          = 0;
     _consts_offset           = data_offset();
     _stub_offset             = data_offset();
     _oops_offset             = data_offset();
     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
     _scopes_pcs_offset       = _scopes_data_offset;
     _dependencies_offset     = _scopes_pcs_offset;
     _handler_table_offset    = _dependencies_offset;
     _nul_chk_table_offset    = _handler_table_offset;
     _nmethod_end_offset      = _nul_chk_table_offset;
     _compile_id              = compile_id;
     _comp_level              = CompLevel_none;
     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
     _osr_entry_point         = NULL;
     _exception_cache         = NULL;
     _pc_desc_cache.reset_to(NULL);
     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
     code_buffer->copy_values_to(this);
     if (ScavengeRootsInCode) {
       if (detect_scavenge_root_oops()) {
         CodeCache::add_scavenge_root_nmethod(this);
       }
       Universe::heap()->register_nmethod(this);
     }
     debug_only(verify_scavenge_root_oops());
     CodeCache::commit(this);
   }
   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
     ttyLocker ttyl;  // keep the following output all in one block
     // This output goes directly to the tty, not the compiler log.
     // To enable tools to match it up with the compilation activity,
     // be sure to tag this tty output with the compile ID.
     if (xtty != NULL) {
       xtty->begin_head("print_native_nmethod");
       xtty->method(_method);
       xtty->stamp();
       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
     }
     // print the header part first
     print();
     // then print the requested information
     if (PrintNativeNMethods) {
       print_code();
       if (oop_maps != NULL) {
         oop_maps->print();
       }
     }
     if (PrintRelocations) {
       print_relocations();
     }
     if (xtty != NULL) {
       xtty->tail("print_native_nmethod");
     }
   }
 }
 // For dtrace wrappers
 #ifdef HAVE_DTRACE_H
 nmethod::nmethod(
   Method* method,
   int nmethod_size,
   CodeOffsets* offsets,
   CodeBuffer* code_buffer,
   int frame_size)
   : CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
   _native_receiver_sp_offset(in_ByteSize(-1)),
   _native_basic_lock_sp_offset(in_ByteSize(-1))
 {
   {
     debug_only(No_Safepoint_Verifier nsv;)
     assert_locked_or_safepoint(CodeCache_lock);
     init_defaults();
     _method                  = method;
     _entry_bci               = InvocationEntryBci;
     // We have no exception handler or deopt handler make the
     // values something that will never match a pc like the nmethod vtable entry
     _exception_offset        = 0;
     _deoptimize_offset       = 0;
     _deoptimize_mh_offset    = 0;
     _unwind_handler_offset   = -1;
     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
     _orig_pc_offset          = 0;
     _consts_offset           = data_offset();
     _stub_offset             = data_offset();
     _oops_offset             = data_offset();
     _metadata_offset         = _oops_offset         + round_to(code_buffer->total_oop_size(), oopSize);
     _scopes_data_offset      = _metadata_offset     + round_to(code_buffer->total_metadata_size(), wordSize);
     _scopes_pcs_offset       = _scopes_data_offset;
     _dependencies_offset     = _scopes_pcs_offset;
     _handler_table_offset    = _dependencies_offset;
     _nul_chk_table_offset    = _handler_table_offset;
     _nmethod_end_offset      = _nul_chk_table_offset;
     _compile_id              = 0;  // default
     _comp_level              = CompLevel_none;
     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
     _osr_entry_point         = NULL;
     _exception_cache         = NULL;
     _pc_desc_cache.reset_to(NULL);
     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
     code_buffer->copy_values_to(this);
     if (ScavengeRootsInCode) {
       if (detect_scavenge_root_oops()) {
         CodeCache::add_scavenge_root_nmethod(this);
       }
       Universe::heap()->register_nmethod(this);
     }
     DEBUG_ONLY(verify_scavenge_root_oops();)
     CodeCache::commit(this);
   }
   if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
     ttyLocker ttyl;  // keep the following output all in one block
     // This output goes directly to the tty, not the compiler log.
     // To enable tools to match it up with the compilation activity,
     // be sure to tag this tty output with the compile ID.
     if (xtty != NULL) {
       xtty->begin_head("print_dtrace_nmethod");
       xtty->method(_method);
       xtty->stamp();
       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
     }
     // print the header part first
     print();
     // then print the requested information
     if (PrintNMethods) {
       print_code();
     }
     if (PrintRelocations) {
       print_relocations();
     }
     if (xtty != NULL) {
       xtty->tail("print_dtrace_nmethod");
     }
   }
 }
 #endif // def HAVE_DTRACE_H
 void* nmethod::operator new(size_t size, int nmethod_size) throw() {
   // Not critical, may return null if there is too little continuous memory
   return CodeCache::allocate(nmethod_size);
 }
 nmethod::nmethod(
   Method* method,
   int nmethod_size,
   int compile_id,
   int entry_bci,
   CodeOffsets* offsets,
   int orig_pc_offset,
   DebugInformationRecorder* debug_info,
   Dependencies* dependencies,
   CodeBuffer *code_buffer,
   int frame_size,
   OopMapSet* oop_maps,
   ExceptionHandlerTable* handler_table,
   ImplicitExceptionTable* nul_chk_table,
   AbstractCompiler* compiler,
   int comp_level
   )
   : CodeBlob("nmethod", code_buffer, sizeof(nmethod),
              nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
   _native_receiver_sp_offset(in_ByteSize(-1)),
   _native_basic_lock_sp_offset(in_ByteSize(-1))
 {
   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
   {
     debug_only(No_Safepoint_Verifier nsv;)
     assert_locked_or_safepoint(CodeCache_lock);
     init_defaults();
     _method                  = method;
     _entry_bci               = entry_bci;
     _compile_id              = compile_id;
     _comp_level              = comp_level;
     _compiler                = compiler;
     _orig_pc_offset          = orig_pc_offset;
     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
     // Section offsets
     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
     // Exception handler and deopt handler are in the stub section
     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
     _exception_offset        = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
     _deoptimize_offset       = _stub_offset          + offsets->value(CodeOffsets::Deopt);
     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
       _deoptimize_mh_offset  = _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
     } else {
       _deoptimize_mh_offset  = -1;
     }
     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
     } else {
       _unwind_handler_offset = -1;
     }
     _oops_offset             = data_offset();
     _metadata_offset         = _oops_offset          + round_to(code_buffer->total_oop_size(), oopSize);
     _scopes_data_offset      = _metadata_offset      + round_to(code_buffer->total_metadata_size(), wordSize);
     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size       (), oopSize);
     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
     _handler_table_offset    = _dependencies_offset  + round_to(dependencies->size_in_bytes (), oopSize);
     _nul_chk_table_offset    = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
     _nmethod_end_offset      = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
     _exception_cache         = NULL;
     _pc_desc_cache.reset_to(scopes_pcs_begin());
     // Copy contents of ScopeDescRecorder to nmethod
     code_buffer->copy_values_to(this);
     debug_info->copy_to(this);
     dependencies->copy_to(this);
     if (ScavengeRootsInCode) {
       if (detect_scavenge_root_oops()) {
         CodeCache::add_scavenge_root_nmethod(this);
       }
       Universe::heap()->register_nmethod(this);
     }
     debug_only(verify_scavenge_root_oops());
     CodeCache::commit(this);
     // Copy contents of ExceptionHandlerTable to nmethod
     handler_table->copy_to(this);
     nul_chk_table->copy_to(this);
     // we use the information of entry points to find out if a method is
     // static or non static
     assert(compiler->is_c2() ||
            _method->is_static() == (entry_point() == _verified_entry_point),
            " entry points must be same for static methods and vice versa");
   }
   bool printnmethods = PrintNMethods
     || CompilerOracle::should_print(_method)
     || CompilerOracle::has_option_string(_method, "PrintNMethods");
   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
     print_nmethod(printnmethods);
   }
 }
 // Print a short set of xml attributes to identify this nmethod.  The
 // output should be embedded in some other element.
 void nmethod::log_identity(xmlStream* log) const {
   log->print(" compile_id='%d'", compile_id());
   const char* nm_kind = compile_kind();
   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
   if (compiler() != NULL) {
     log->print(" compiler='%s'", compiler()->name());
   }
   if (TieredCompilation) {
     log->print(" level='%d'", comp_level());
   }
 }
 #define LOG_OFFSET(log, name)                    \
   if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
     log->print(" " XSTR(name) "_offset='%d'"    , \
                (intptr_t)name##_begin() - (intptr_t)this)
 void nmethod::log_new_nmethod() const {
   if (LogCompilation && xtty != NULL) {
     ttyLocker ttyl;
     HandleMark hm;
     xtty->begin_elem("nmethod");
     log_identity(xtty);
     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
     xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
     LOG_OFFSET(xtty, relocation);
     LOG_OFFSET(xtty, consts);
     LOG_OFFSET(xtty, insts);
     LOG_OFFSET(xtty, stub);
     LOG_OFFSET(xtty, scopes_data);
     LOG_OFFSET(xtty, scopes_pcs);
     LOG_OFFSET(xtty, dependencies);
     LOG_OFFSET(xtty, handler_table);
     LOG_OFFSET(xtty, nul_chk_table);
     LOG_OFFSET(xtty, oops);
     xtty->method(method());
     xtty->stamp();
     xtty->end_elem();
   }
 }
 #undef LOG_OFFSET
 // Print out more verbose output usually for a newly created nmethod.
 void nmethod::print_on(outputStream* st, const char* msg) const {
   if (st != NULL) {
     ttyLocker ttyl;
     if (WizardMode) {
       CompileTask::print_compilation(st, this, msg, /*short_form:*/ true);
       st->print_cr(" (" INTPTR_FORMAT ")", this);
     } else {
       CompileTask::print_compilation(st, this, msg, /*short_form:*/ false);
     }
   }
 }
 void nmethod::print_nmethod(bool printmethod) {
   ttyLocker ttyl;  // keep the following output all in one block
   if (xtty != NULL) {
     xtty->begin_head("print_nmethod");
     xtty->stamp();
     xtty->end_head();
   }
   // print the header part first
   print();
   // then print the requested information
   if (printmethod) {
     print_code();
     print_pcs();
     if (oop_maps()) {
       oop_maps()->print();
     }
   }
   if (PrintDebugInfo) {
     print_scopes();
   }
   if (PrintRelocations) {
     print_relocations();
   }
   if (PrintDependencies) {
     print_dependencies();
   }
   if (PrintExceptionHandlers) {
     print_handler_table();
     print_nul_chk_table();
   }
   if (xtty != NULL) {
     xtty->tail("print_nmethod");
   }
 }
 // Promote one word from an assembly-time handle to a live embedded oop.
 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
   if (handle == NULL ||
       // As a special case, IC oops are initialized to 1 or -1.
       handle == (jobject) Universe::non_oop_word()) {
     (*dest) = (oop) handle;
   } else {
     (*dest) = JNIHandles::resolve_non_null(handle);
   }
 }
 // Have to have the same name because it's called by a template
 void nmethod::copy_values(GrowableArray<jobject>* array) {
   int length = array->length();
   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
   oop* dest = oops_begin();
   for (int index = 0 ; index < length; index++) {
     initialize_immediate_oop(&dest[index], array->at(index));
   }
   // Now we can fix up all the oops in the code.  We need to do this
   // in the code because the assembler uses jobjects as placeholders.
   // The code and relocations have already been initialized by the
   // CodeBlob constructor, so it is valid even at this early point to
   // iterate over relocations and patch the code.
   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
 }
 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
   int length = array->length();
   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
   Metadata** dest = metadata_begin();
   for (int index = 0 ; index < length; index++) {
     dest[index] = array->at(index);
   }
 }
 bool nmethod::is_at_poll_return(address pc) {
   RelocIterator iter(this, pc, pc+1);
   while (iter.next()) {
     if (iter.type() == relocInfo::poll_return_type)
       return true;
   }
   return false;
 }
 bool nmethod::is_at_poll_or_poll_return(address pc) {
   RelocIterator iter(this, pc, pc+1);
   while (iter.next()) {
     relocInfo::relocType t = iter.type();
     if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
       return true;
   }
   return false;
 }
 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
   // re-patch all oop-bearing instructions, just in case some oops moved
   RelocIterator iter(this, begin, end);
   while (iter.next()) {
     if (iter.type() == relocInfo::oop_type) {
       oop_Relocation* reloc = iter.oop_reloc();
       if (initialize_immediates && reloc->oop_is_immediate()) {
         oop* dest = reloc->oop_addr();
         initialize_immediate_oop(dest, (jobject) *dest);
       }
       // Refresh the oop-related bits of this instruction.
       reloc->fix_oop_relocation();
     } else if (iter.type() == relocInfo::metadata_type) {
       metadata_Relocation* reloc = iter.metadata_reloc();
       reloc->fix_metadata_relocation();
     }
   }
 }
 void nmethod::verify_oop_relocations() {
   // Ensure sure that the code matches the current oop values
   RelocIterator iter(this, NULL, NULL);
   while (iter.next()) {
     if (iter.type() == relocInfo::oop_type) {
       oop_Relocation* reloc = iter.oop_reloc();
       if (!reloc->oop_is_immediate()) {
         reloc->verify_oop_relocation();
       }
     }
   }
 }
 ScopeDesc* nmethod::scope_desc_at(address pc) {
   PcDesc* pd = pc_desc_at(pc);
   guarantee(pd != NULL, "scope must be present");
   return new ScopeDesc(this, pd->scope_decode_offset(),
                        pd->obj_decode_offset(), pd->should_reexecute(),
                        pd->return_oop());
 }
 void nmethod::clear_inline_caches() {
   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
   if (is_zombie()) {
     return;
   }
   RelocIterator iter(this);
   while (iter.next()) {
     iter.reloc()->clear_inline_cache();
   }
 }
 // Clear ICStubs of all compiled ICs
 void nmethod::clear_ic_stubs() {
   assert_locked_or_safepoint(CompiledIC_lock);
   RelocIterator iter(this);
   while(iter.next()) {
     if (iter.type() == relocInfo::virtual_call_type) {
       CompiledIC* ic = CompiledIC_at(&iter);
       ic->clear_ic_stub();
     }
   }
 }
 void nmethod::cleanup_inline_caches() {
   assert_locked_or_safepoint(CompiledIC_lock);
   // If the method is not entrant or zombie then a JMP is plastered over the
   // first few bytes.  If an oop in the old code was there, that oop
   // should not get GC'd.  Skip the first few bytes of oops on
   // not-entrant methods.
   address low_boundary = verified_entry_point();
   if (!is_in_use()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // This means that the low_boundary is going to be a little too high.
     // This shouldn't matter, since oops of non-entrant methods are never used.
     // In fact, why are we bothering to look at oops in a non-entrant method??
   }
   // Find all calls in an nmethod and clear the ones that point to non-entrant,
   // zombie and unloaded nmethods.
   ResourceMark rm;
   RelocIterator iter(this, low_boundary);
   while(iter.next()) {
     switch(iter.type()) {
       case relocInfo::virtual_call_type:
       case relocInfo::opt_virtual_call_type: {
         CompiledIC *ic = CompiledIC_at(&iter);
         // Ok, to lookup references to zombies here
         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
         if( cb != NULL && cb->is_nmethod() ) {
           nmethod* nm = (nmethod*)cb;
           // Clean inline caches pointing to zombie, non-entrant and unloaded methods
           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive());
         }
         break;
       }
       case relocInfo::static_call_type: {
         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
         if( cb != NULL && cb->is_nmethod() ) {
           nmethod* nm = (nmethod*)cb;
           // Clean inline caches pointing to zombie, non-entrant and unloaded methods
           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
         }
         break;
       }
     }
   }
 }
 void nmethod::verify_clean_inline_caches() {
   assert_locked_or_safepoint(CompiledIC_lock);
   // If the method is not entrant or zombie then a JMP is plastered over the
   // first few bytes.  If an oop in the old code was there, that oop
   // should not get GC'd.  Skip the first few bytes of oops on
   // not-entrant methods.
   address low_boundary = verified_entry_point();
   if (!is_in_use()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // This means that the low_boundary is going to be a little too high.
     // This shouldn't matter, since oops of non-entrant methods are never used.
     // In fact, why are we bothering to look at oops in a non-entrant method??
   }
   ResourceMark rm;
   RelocIterator iter(this, low_boundary);
   while(iter.next()) {
     switch(iter.type()) {
       case relocInfo::virtual_call_type:
       case relocInfo::opt_virtual_call_type: {
         CompiledIC *ic = CompiledIC_at(&iter);
         // Ok, to lookup references to zombies here
         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
         if( cb != NULL && cb->is_nmethod() ) {
           nmethod* nm = (nmethod*)cb;
           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
             assert(ic->is_clean(), "IC should be clean");
           }
         }
         break;
       }
       case relocInfo::static_call_type: {
         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
         if( cb != NULL && cb->is_nmethod() ) {
           nmethod* nm = (nmethod*)cb;
           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
             assert(csc->is_clean(), "IC should be clean");
           }
         }
         break;
       }
     }
   }
 }
 int nmethod::verify_icholder_relocations() {
   int count = 0;
   RelocIterator iter(this);
   while(iter.next()) {
     if (iter.type() == relocInfo::virtual_call_type) {
       if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc())) {
         CompiledIC *ic = CompiledIC_at(&iter);
         if (TraceCompiledIC) {
           tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
           ic->print();
         }
         assert(ic->cached_icholder() != NULL, "must be non-NULL");
         count++;
       }
     }
   }
   return count;
 }
 // This is a private interface with the sweeper.
 void nmethod::mark_as_seen_on_stack() {
   assert(is_alive(), "Must be an alive method");
   // Set the traversal mark to ensure that the sweeper does 2
   // cleaning passes before moving to zombie.
   set_stack_traversal_mark(NMethodSweeper::traversal_count());
 }
 // Tell if a non-entrant method can be converted to a zombie (i.e.,
 // there are no activations on the stack, not in use by the VM,
 // and not in use by the ServiceThread)
 bool nmethod::can_convert_to_zombie() {
   assert(is_not_entrant(), "must be a non-entrant method");
   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
   // count can be greater than the stack traversal count before it hits the
   // nmethod for the second time.
   return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
          !is_locked_by_vm();
 }
 void nmethod::inc_decompile_count() {
   if (!is_compiled_by_c2()) return;
   // Could be gated by ProfileTraps, but do not bother...
   Method* m = method();
   if (m == NULL)  return;
   MethodData* mdo = m->method_data();
   if (mdo == NULL)  return;
   // There is a benign race here.  See comments in methodData.hpp.
   mdo->inc_decompile_count();
 }
 void nmethod::increase_unloading_clock() {
   _global_unloading_clock++;
   if (_global_unloading_clock == 0) {
     // _nmethods are allocated with _unloading_clock == 0,
     // so 0 is never used as a clock value.
     _global_unloading_clock = 1;
   }
 }
 void nmethod::set_unloading_clock(unsigned char unloading_clock) {
   OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock);
 }
 unsigned char nmethod::unloading_clock() {
   return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock);
 }
 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
   post_compiled_method_unload();
   // Since this nmethod is being unloaded, make sure that dependencies
   // recorded in instanceKlasses get flushed and pass non-NULL closure to
   // indicate that this work is being done during a GC.
   assert(Universe::heap()->is_gc_active(), "should only be called during gc");
   assert(is_alive != NULL, "Should be non-NULL");
   // A non-NULL is_alive closure indicates that this is being called during GC.
   flush_dependencies(is_alive);
   // Break cycle between nmethod & method
   if (TraceClassUnloading && WizardMode) {
     tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
                   " unloadable], Method*(" INTPTR_FORMAT
                   "), cause(" INTPTR_FORMAT ")",
                   this, (address)_method, (address)cause);
     if (!Universe::heap()->is_gc_active())
       cause->klass()->print();
   }
   // Unlink the osr method, so we do not look this up again
   if (is_osr_method()) {
     invalidate_osr_method();
   }
   // If _method is already NULL the Method* is about to be unloaded,
   // so we don't have to break the cycle. Note that it is possible to
   // have the Method* live here, in case we unload the nmethod because
   // it is pointing to some oop (other than the Method*) being unloaded.
   if (_method != NULL) {
     // OSR methods point to the Method*, but the Method* does not
     // point back!
     if (_method->code() == this) {
       _method->clear_code(); // Break a cycle
     }
     _method = NULL;            // Clear the method of this dead nmethod
   }
   // Make the class unloaded - i.e., change state and notify sweeper
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
   if (is_in_use()) {
     // Transitioning directly from live to unloaded -- so
     // we need to force a cache clean-up; remember this
     // for later on.
     CodeCache::set_needs_cache_clean(true);
   }
   // Unregister must be done before the state change
   Universe::heap()->unregister_nmethod(this);
   _state = unloaded;
   // Log the unloading.
   log_state_change();
   // The Method* is gone at this point
   assert(_method == NULL, "Tautology");
   set_osr_link(NULL);
   //set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
   NMethodSweeper::report_state_change(this);
 }
 void nmethod::invalidate_osr_method() {
   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
   // Remove from list of active nmethods
   if (method() != NULL)
     method()->method_holder()->remove_osr_nmethod(this);
   // Set entry as invalid
   _entry_bci = InvalidOSREntryBci;
 }
 void nmethod::log_state_change() const {
   if (LogCompilation) {
     if (xtty != NULL) {
       ttyLocker ttyl;  // keep the following output all in one block
       if (_state == unloaded) {
         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
                          os::current_thread_id());
       } else {
         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
                          os::current_thread_id(),
                          (_state == zombie ? " zombie='1'" : ""));
       }
       log_identity(xtty);
       xtty->stamp();
       xtty->end_elem();
     }
   }
   if (PrintCompilation && _state != unloaded) {
     print_on(tty, _state == zombie ? "made zombie" : "made not entrant");
   }
 }
 /**
  * Common functionality for both make_not_entrant and make_zombie
  */
 bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
   assert(!is_zombie(), "should not already be a zombie");
   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
   nmethodLocker nml(this);
   methodHandle the_method(method());
   No_Safepoint_Verifier nsv;
   // during patching, depending on the nmethod state we must notify the GC that
   // code has been unloaded, unregistering it. We cannot do this right while
   // holding the Patching_lock because we need to use the CodeCache_lock. This
   // would be prone to deadlocks.
   // This flag is used to remember whether we need to later lock and unregister.
   bool nmethod_needs_unregister = false;
   {
     // invalidate osr nmethod before acquiring the patching lock since
     // they both acquire leaf locks and we don't want a deadlock.
     // This logic is equivalent to the logic below for patching the
     // verified entry point of regular methods.
     if (is_osr_method()) {
       // this effectively makes the osr nmethod not entrant
       invalidate_osr_method();
     }
     // Enter critical section.  Does not block for safepoint.
     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
     if (_state == state) {
       // another thread already performed this transition so nothing
       // to do, but return false to indicate this.
       return false;
     }
     // The caller can be calling the method statically or through an inline
     // cache call.
     if (!is_osr_method() && !is_not_entrant()) {
       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
                   SharedRuntime::get_handle_wrong_method_stub());
     }
     if (is_in_use()) {
       // It's a true state change, so mark the method as decompiled.
       // Do it only for transition from alive.
       inc_decompile_count();
     }
     // If the state is becoming a zombie, signal to unregister the nmethod with
     // the heap.
     // This nmethod may have already been unloaded during a full GC.
     if ((state == zombie) && !is_unloaded()) {
       nmethod_needs_unregister = true;
     }
     // Must happen before state change. Otherwise we have a race condition in
     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
     // transition its state from 'not_entrant' to 'zombie' without having to wait
     // for stack scanning.
     if (state == not_entrant) {
       mark_as_seen_on_stack();
       OrderAccess::storestore();
     }
     // Change state
     _state = state;
     // Log the transition once
     log_state_change();
     // Remove nmethod from method.
     // We need to check if both the _code and _from_compiled_code_entry_point
     // refer to this nmethod because there is a race in setting these two fields
     // in Method* as seen in bugid 4947125.
     // If the vep() points to the zombie nmethod, the memory for the nmethod
     // could be flushed and the compiler and vtable stubs could still call
     // through it.
     if (method() != NULL && (method()->code() == this ||
                              method()->from_compiled_entry() == verified_entry_point())) {
       HandleMark hm;
       method()->clear_code();
     }
   } // leave critical region under Patching_lock
   // When the nmethod becomes zombie it is no longer alive so the
   // dependencies must be flushed.  nmethods in the not_entrant
   // state will be flushed later when the transition to zombie
   // happens or they get unloaded.
   if (state == zombie) {
     {
       // Flushing dependecies must be done before any possible
       // safepoint can sneak in, otherwise the oops used by the
       // dependency logic could have become stale.
       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
       if (nmethod_needs_unregister) {
         Universe::heap()->unregister_nmethod(this);
       }
       flush_dependencies(NULL);
     }
     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
     // event and it hasn't already been reported for this nmethod then
     // report it now. The event may have been reported earilier if the GC
     // marked it for unloading). JvmtiDeferredEventQueue support means
     // we no longer go to a safepoint here.
     post_compiled_method_unload();
 #ifdef ASSERT
     // It's no longer safe to access the oops section since zombie
     // nmethods aren't scanned for GC.
     _oops_are_stale = true;
 #endif
      // the Method may be reclaimed by class unloading now that the
      // nmethod is in zombie state
     set_method(NULL);
   } else {
     assert(state == not_entrant, "other cases may need to be handled differently");
   }
   if (TraceCreateZombies) {
     tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
   }
   NMethodSweeper::report_state_change(this);
   return true;
 }
 void nmethod::flush() {
   // Note that there are no valid oops in the nmethod anymore.
   assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
   assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
   assert_locked_or_safepoint(CodeCache_lock);
   // completely deallocate this method
   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, this);
   if (PrintMethodFlushing) {
     tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
         _compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
   }
   // We need to deallocate any ExceptionCache data.
   // Note that we do not need to grab the nmethod lock for this, it
   // better be thread safe if we're disposing of it!
   ExceptionCache* ec = exception_cache();
   set_exception_cache(NULL);
   while(ec != NULL) {
     ExceptionCache* next = ec->next();
     delete ec;
     ec = next;
   }
   if (on_scavenge_root_list()) {
     CodeCache::drop_scavenge_root_nmethod(this);
   }
 #ifdef SHARK
   ((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
 #endif // SHARK
   ((CodeBlob*)(this))->flush();
   CodeCache::free(this);
 }
 //
 // Notify all classes this nmethod is dependent on that it is no
 // longer dependent. This should only be called in two situations.
 // First, when a nmethod transitions to a zombie all dependents need
 // to be clear.  Since zombification happens at a safepoint there's no
 // synchronization issues.  The second place is a little more tricky.
 // During phase 1 of mark sweep class unloading may happen and as a
 // result some nmethods may get unloaded.  In this case the flushing
 // of dependencies must happen during phase 1 since after GC any
 // dependencies in the unloaded nmethod won't be updated, so
 // traversing the dependency information in unsafe.  In that case this
 // function is called with a non-NULL argument and this function only
 // notifies instanceKlasses that are reachable
 void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
   assert_locked_or_safepoint(CodeCache_lock);
   assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
   "is_alive is non-NULL if and only if we are called during GC");
   if (!has_flushed_dependencies()) {
     set_has_flushed_dependencies();
     for (Dependencies::DepStream deps(this); deps.next(); ) {
       Klass* klass = deps.context_type();
       if (klass == NULL)  continue;  // ignore things like evol_method
       // During GC the is_alive closure is non-NULL, and is used to
       // determine liveness of dependees that need to be updated.
       if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
         // The GC defers deletion of this entry, since there might be multiple threads
         // iterating over the _dependencies graph. Other call paths are single-threaded
         // and may delete it immediately.
         bool delete_immediately = is_alive == NULL;
         InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
       }
     }
   }
 }
 // If this oop is not live, the nmethod can be unloaded.
 bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred) {
   assert(root != NULL, "just checking");
   oop obj = *root;
   if (obj == NULL || is_alive->do_object_b(obj)) {
       return false;
   }
   // If ScavengeRootsInCode is true, an nmethod might be unloaded
   // simply because one of its constant oops has gone dead.
   // No actual classes need to be unloaded in order for this to occur.
   assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
   make_unloaded(is_alive, obj);
   return true;
 }
 // ------------------------------------------------------------------
 // post_compiled_method_load_event
 // new method for install_code() path
 // Transfer information from compilation to jvmti
 void nmethod::post_compiled_method_load_event() {
   Method* moop = method();
 #ifndef USDT2
   HS_DTRACE_PROBE8(hotspot, compiled__method__load,
       moop->klass_name()->bytes(),
       moop->klass_name()->utf8_length(),
       moop->name()->bytes(),
       moop->name()->utf8_length(),
       moop->signature()->bytes(),
       moop->signature()->utf8_length(),
       insts_begin(), insts_size());
 #else /* USDT2 */
   HOTSPOT_COMPILED_METHOD_LOAD(
       (char *) moop->klass_name()->bytes(),
       moop->klass_name()->utf8_length(),
       (char *) moop->name()->bytes(),
       moop->name()->utf8_length(),
       (char *) moop->signature()->bytes(),
       moop->signature()->utf8_length(),
       insts_begin(), insts_size());
 #endif /* USDT2 */
   if (JvmtiExport::should_post_compiled_method_load() ||
       JvmtiExport::should_post_compiled_method_unload()) {
     get_and_cache_jmethod_id();
   }
   if (JvmtiExport::should_post_compiled_method_load()) {
     // Let the Service thread (which is a real Java thread) post the event
     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
     JvmtiDeferredEventQueue::enqueue(
       JvmtiDeferredEvent::compiled_method_load_event(this));
   }
 }
 jmethodID nmethod::get_and_cache_jmethod_id() {
   if (_jmethod_id == NULL) {
     // Cache the jmethod_id since it can no longer be looked up once the
     // method itself has been marked for unloading.
     _jmethod_id = method()->jmethod_id();
   }
   return _jmethod_id;
 }
 void nmethod::post_compiled_method_unload() {
   if (unload_reported()) {
     // During unloading we transition to unloaded and then to zombie
     // and the unloading is reported during the first transition.
     return;
   }
   assert(_method != NULL && !is_unloaded(), "just checking");
   DTRACE_METHOD_UNLOAD_PROBE(method());
   // If a JVMTI agent has enabled the CompiledMethodUnload event then
   // post the event. Sometime later this nmethod will be made a zombie
   // by the sweeper but the Method* will not be valid at that point.
   // If the _jmethod_id is null then no load event was ever requested
   // so don't bother posting the unload.  The main reason for this is
   // that the jmethodID is a weak reference to the Method* so if
   // it's being unloaded there's no way to look it up since the weak
   // ref will have been cleared.
   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
     assert(!unload_reported(), "already unloaded");
     JvmtiDeferredEvent event =
       JvmtiDeferredEvent::compiled_method_unload_event(this,
           _jmethod_id, insts_begin());
     if (SafepointSynchronize::is_at_safepoint()) {
       // Don't want to take the queueing lock. Add it as pending and
       // it will get enqueued later.
       JvmtiDeferredEventQueue::add_pending_event(event);
     } else {
       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
       JvmtiDeferredEventQueue::enqueue(event);
     }
   }
   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
   // any time. As the nmethod is being unloaded now we mark it has
   // having the unload event reported - this will ensure that we don't
   // attempt to report the event in the unlikely scenario where the
   // event is enabled at the time the nmethod is made a zombie.
   set_unload_reported();
 }
 void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive, bool mark_on_stack) {
   if (ic->is_icholder_call()) {
     // The only exception is compiledICHolder oops which may
     // yet be marked below. (We check this further below).
     CompiledICHolder* cichk_oop = ic->cached_icholder();
     if (mark_on_stack) {
       Metadata::mark_on_stack(cichk_oop->holder_method());
       Metadata::mark_on_stack(cichk_oop->holder_klass());
     }
     if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
         cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
       return;
     }
   } else {
     Metadata* ic_oop = ic->cached_metadata();
     if (ic_oop != NULL) {
       if (mark_on_stack) {
         Metadata::mark_on_stack(ic_oop);
       }
       if (ic_oop->is_klass()) {
         if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
           return;
         }
       } else if (ic_oop->is_method()) {
         if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
           return;
         }
       } else {
         ShouldNotReachHere();
       }
     }
   }
   ic->set_to_clean();
 }
 // This is called at the end of the strong tracing/marking phase of a
 // GC to unload an nmethod if it contains otherwise unreachable
 // oops.
 void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
   // Make sure the oop's ready to receive visitors
   assert(!is_zombie() && !is_unloaded(),
          "should not call follow on zombie or unloaded nmethod");
   // If the method is not entrant then a JMP is plastered over the
   // first few bytes.  If an oop in the old code was there, that oop
   // should not get GC'd.  Skip the first few bytes of oops on
   // not-entrant methods.
   address low_boundary = verified_entry_point();
   if (is_not_entrant()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // (See comment above.)
   }
   // The RedefineClasses() API can cause the class unloading invariant
   // to no longer be true. See jvmtiExport.hpp for details.
   // Also, leave a debugging breadcrumb in local flag.
   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
   if (a_class_was_redefined) {
     // This set of the unloading_occurred flag is done before the
     // call to post_compiled_method_unload() so that the unloading
     // of this nmethod is reported.
     unloading_occurred = true;
   }
   // Exception cache
   clean_exception_cache(is_alive);
   // If class unloading occurred we first iterate over all inline caches and
   // clear ICs where the cached oop is referring to an unloaded klass or method.
   // The remaining live cached oops will be traversed in the relocInfo::oop_type
   // iteration below.
   if (unloading_occurred) {
     RelocIterator iter(this, low_boundary);
     while(iter.next()) {
       if (iter.type() == relocInfo::virtual_call_type) {
         CompiledIC *ic = CompiledIC_at(&iter);
         clean_ic_if_metadata_is_dead(ic, is_alive, false);
       }
     }
   }
   // Compiled code
   {
   RelocIterator iter(this, low_boundary);
   while (iter.next()) {
     if (iter.type() == relocInfo::oop_type) {
       oop_Relocation* r = iter.oop_reloc();
       // In this loop, we must only traverse those oops directly embedded in
       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
       assert(1 == (r->oop_is_immediate()) +
                   (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
              "oop must be found in exactly one place");
       if (r->oop_is_immediate() && r->oop_value() != NULL) {
         if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
           return;
         }
       }
     }
   }
   }
   // Scopes
   for (oop* p = oops_begin(); p < oops_end(); p++) {
     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
     if (can_unload(is_alive, p, unloading_occurred)) {
       return;
     }
   }
   // Ensure that all metadata is still alive
   verify_metadata_loaders(low_boundary, is_alive);
 }
 template <class CompiledICorStaticCall>
 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, nmethod* from) {
   // Ok, to lookup references to zombies here
   CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
   if (cb != NULL && cb->is_nmethod()) {
     nmethod* nm = (nmethod*)cb;
     if (nm->unloading_clock() != nmethod::global_unloading_clock()) {
       // The nmethod has not been processed yet.
       return true;
     }
     // Clean inline caches pointing to both zombie and not_entrant methods
     if (!nm->is_in_use() || (nm->method()->code() != nm)) {
       ic->set_to_clean();
       assert(ic->is_clean(), err_msg("nmethod " PTR_FORMAT "not clean %s", from, from->method()->name_and_sig_as_C_string()));
     }
   }
   return false;
 }
 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, nmethod* from) {
   return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from);
 }
 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, nmethod* from) {
   return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from);
 }
 bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) {
   assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
   oop_Relocation* r = iter_at_oop->oop_reloc();
   // Traverse those oops directly embedded in the code.
   // Other oops (oop_index>0) are seen as part of scopes_oops.
   assert(1 == (r->oop_is_immediate()) +
          (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
          "oop must be found in exactly one place");
   if (r->oop_is_immediate() && r->oop_value() != NULL) {
     // Unload this nmethod if the oop is dead.
     if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
       return true;;
     }
   }
   return false;
 }
 void nmethod::mark_metadata_on_stack_at(RelocIterator* iter_at_metadata) {
   assert(iter_at_metadata->type() == relocInfo::metadata_type, "Wrong relocation type");
   metadata_Relocation* r = iter_at_metadata->metadata_reloc();
   // In this metadata, we must only follow those metadatas directly embedded in
   // the code.  Other metadatas (oop_index>0) are seen as part of
   // the metadata section below.
   assert(1 == (r->metadata_is_immediate()) +
          (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
          "metadata must be found in exactly one place");
   if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
     Metadata* md = r->metadata_value();
     if (md != _method) Metadata::mark_on_stack(md);
   }
 }
 void nmethod::mark_metadata_on_stack_non_relocs() {
     // Visit the metadata section
     for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
       if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
       Metadata* md = *p;
       Metadata::mark_on_stack(md);
     }
     // Visit metadata not embedded in the other places.
     if (_method != NULL) Metadata::mark_on_stack(_method);
 }
 bool nmethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
   ResourceMark rm;
   // Make sure the oop's ready to receive visitors
   assert(!is_zombie() && !is_unloaded(),
          "should not call follow on zombie or unloaded nmethod");
   // If the method is not entrant then a JMP is plastered over the
   // first few bytes.  If an oop in the old code was there, that oop
   // should not get GC'd.  Skip the first few bytes of oops on
   // not-entrant methods.
   address low_boundary = verified_entry_point();
   if (is_not_entrant()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // (See comment above.)
   }
   // The RedefineClasses() API can cause the class unloading invariant
   // to no longer be true. See jvmtiExport.hpp for details.
   // Also, leave a debugging breadcrumb in local flag.
   bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
   if (a_class_was_redefined) {
     // This set of the unloading_occurred flag is done before the
     // call to post_compiled_method_unload() so that the unloading
     // of this nmethod is reported.
     unloading_occurred = true;
   }
   // When class redefinition is used all metadata in the CodeCache has to be recorded,
   // so that unused "previous versions" can be purged. Since walking the CodeCache can
   // be expensive, the "mark on stack" is piggy-backed on this parallel unloading code.
   bool mark_metadata_on_stack = a_class_was_redefined;
   // Exception cache
   clean_exception_cache(is_alive);
   bool is_unloaded = false;
   bool postponed = false;
   RelocIterator iter(this, low_boundary);
   while(iter.next()) {
     switch (iter.type()) {
     case relocInfo::virtual_call_type:
       if (unloading_occurred) {
         // If class unloading occurred we first iterate over all inline caches and
         // clear ICs where the cached oop is referring to an unloaded klass or method.
         clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive, mark_metadata_on_stack);
       }
       postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
       break;
     case relocInfo::opt_virtual_call_type:
       postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
       break;
     case relocInfo::static_call_type:
       postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
       break;
     case relocInfo::oop_type:
       if (!is_unloaded) {
         is_unloaded = unload_if_dead_at(&iter, is_alive, unloading_occurred);
       }
       break;
     case relocInfo::metadata_type:
       if (mark_metadata_on_stack) {
         mark_metadata_on_stack_at(&iter);
       }
     }
   }
   if (mark_metadata_on_stack) {
     mark_metadata_on_stack_non_relocs();
   }
   if (is_unloaded) {
     return postponed;
   }
   // Scopes
   for (oop* p = oops_begin(); p < oops_end(); p++) {
     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
     if (can_unload(is_alive, p, unloading_occurred)) {
       is_unloaded = true;
       break;
     }
   }
   if (is_unloaded) {
     return postponed;
   }
   // Ensure that all metadata is still alive
   verify_metadata_loaders(low_boundary, is_alive);
   return postponed;
 }
 void nmethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) {
   ResourceMark rm;
   // Make sure the oop's ready to receive visitors
   assert(!is_zombie(),
          "should not call follow on zombie nmethod");
   // If the method is not entrant then a JMP is plastered over the
   // first few bytes.  If an oop in the old code was there, that oop
   // should not get GC'd.  Skip the first few bytes of oops on
   // not-entrant methods.
   address low_boundary = verified_entry_point();
   if (is_not_entrant()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // (See comment above.)
   }
   RelocIterator iter(this, low_boundary);
   while(iter.next()) {
     switch (iter.type()) {
     case relocInfo::virtual_call_type:
       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
       break;
     case relocInfo::opt_virtual_call_type:
       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
       break;
     case relocInfo::static_call_type:
       clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
       break;
     }
   }
 }
 #ifdef ASSERT
 class CheckClass : AllStatic {
   static BoolObjectClosure* _is_alive;
   // Check class_loader is alive for this bit of metadata.
   static void check_class(Metadata* md) {
     Klass* klass = NULL;
     if (md->is_klass()) {
       klass = ((Klass*)md);
     } else if (md->is_method()) {
       klass = ((Method*)md)->method_holder();
     } else if (md->is_methodData()) {
       klass = ((MethodData*)md)->method()->method_holder();
     } else {
       md->print();
       ShouldNotReachHere();
     }
     assert(klass->is_loader_alive(_is_alive), "must be alive");
   }
  public:
   static void do_check_class(BoolObjectClosure* is_alive, nmethod* nm) {
     assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint");
     _is_alive = is_alive;
     nm->metadata_do(check_class);
   }
 };
 // This is called during a safepoint so can use static data
 BoolObjectClosure* CheckClass::_is_alive = NULL;
 #endif // ASSERT
 // Processing of oop references should have been sufficient to keep
 // all strong references alive.  Any weak references should have been
 // cleared as well.  Visit all the metadata and ensure that it's
 // really alive.
 void nmethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) {
 #ifdef ASSERT
     RelocIterator iter(this, low_boundary);
     while (iter.next()) {
     // static_stub_Relocations may have dangling references to
     // Method*s so trim them out here.  Otherwise it looks like
     // compiled code is maintaining a link to dead metadata.
     address static_call_addr = NULL;
     if (iter.type() == relocInfo::opt_virtual_call_type) {
       CompiledIC* cic = CompiledIC_at(&iter);
       if (!cic->is_call_to_interpreted()) {
         static_call_addr = iter.addr();
       }
     } else if (iter.type() == relocInfo::static_call_type) {
       CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc());
       if (!csc->is_call_to_interpreted()) {
         static_call_addr = iter.addr();
       }
     }
     if (static_call_addr != NULL) {
       RelocIterator sciter(this, low_boundary);
       while (sciter.next()) {
         if (sciter.type() == relocInfo::static_stub_type &&
             sciter.static_stub_reloc()->static_call() == static_call_addr) {
           sciter.static_stub_reloc()->clear_inline_cache();
         }
       }
     }
   }
   // Check that the metadata embedded in the nmethod is alive
   CheckClass::do_check_class(is_alive, this);
 #endif
 }
 // Iterate over metadata calling this function.   Used by RedefineClasses
 void nmethod::metadata_do(void f(Metadata*)) {
   address low_boundary = verified_entry_point();
   if (is_not_entrant()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // (See comment above.)
   }
   {
     // Visit all immediate references that are embedded in the instruction stream.
     RelocIterator iter(this, low_boundary);
     while (iter.next()) {
       if (iter.type() == relocInfo::metadata_type ) {
         metadata_Relocation* r = iter.metadata_reloc();
         // In this metadata, we must only follow those metadatas directly embedded in
         // the code.  Other metadatas (oop_index>0) are seen as part of
         // the metadata section below.
         assert(1 == (r->metadata_is_immediate()) +
                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
                "metadata must be found in exactly one place");
         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
           Metadata* md = r->metadata_value();
           f(md);
         }
       } else if (iter.type() == relocInfo::virtual_call_type) {
         // Check compiledIC holders associated with this nmethod
         CompiledIC *ic = CompiledIC_at(&iter);
         if (ic->is_icholder_call()) {
           CompiledICHolder* cichk = ic->cached_icholder();
           f(cichk->holder_method());
           f(cichk->holder_klass());
         } else {
           Metadata* ic_oop = ic->cached_metadata();
           if (ic_oop != NULL) {
             f(ic_oop);
           }
         }
       }
     }
   }
   // Visit the metadata section
   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
     Metadata* md = *p;
     f(md);
   }
   // Visit metadata not embedded in the other places.
   if (_method != NULL) f(_method);
 }
 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
   // make sure the oops ready to receive visitors
   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
   // If the method is not entrant or zombie then a JMP is plastered over the
   // first few bytes.  If an oop in the old code was there, that oop
   // should not get GC'd.  Skip the first few bytes of oops on
   // not-entrant methods.
   address low_boundary = verified_entry_point();
   if (is_not_entrant()) {
     low_boundary += NativeJump::instruction_size;
     // %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
     // (See comment above.)
   }
   RelocIterator iter(this, low_boundary);
   while (iter.next()) {
     if (iter.type() == relocInfo::oop_type ) {
       oop_Relocation* r = iter.oop_reloc();
       // In this loop, we must only follow those oops directly embedded in
       // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
       assert(1 == (r->oop_is_immediate()) +
                    (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
              "oop must be found in exactly one place");
       if (r->oop_is_immediate() && r->oop_value() != NULL) {
         f->do_oop(r->oop_addr());
       }
     }
   }
   // Scopes
   // This includes oop constants not inlined in the code stream.
   for (oop* p = oops_begin(); p < oops_end(); p++) {
     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
     f->do_oop(p);
   }
 }
 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
 nmethod* volatile nmethod::_oops_do_mark_nmethods;
 // An nmethod is "marked" if its _mark_link is set non-null.
 // Even if it is the end of the linked list, it will have a non-null link value,
 // as long as it is on the list.
 // This code must be MP safe, because it is used from parallel GC passes.
 bool nmethod::test_set_oops_do_mark() {
   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
   nmethod* observed_mark_link = _oops_do_mark_link;
   if (observed_mark_link == NULL) {
     // Claim this nmethod for this thread to mark.
     observed_mark_link = (nmethod*)
       Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
     if (observed_mark_link == NULL) {
       // Atomically append this nmethod (now claimed) to the head of the list:
       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
       for (;;) {
         nmethod* required_mark_nmethods = observed_mark_nmethods;
         _oops_do_mark_link = required_mark_nmethods;
         observed_mark_nmethods = (nmethod*)
           Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
         if (observed_mark_nmethods == required_mark_nmethods)
           break;
       }
       // Mark was clear when we first saw this guy.
       NOT_PRODUCT(if (TraceScavenge)  print_on(tty, "oops_do, mark"));
       return false;
     }
   }
   // On fall through, another racing thread marked this nmethod before we did.
   return true;
 }
 void nmethod::oops_do_marking_prologue() {
   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("[oops_do_marking_prologue"));
   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
   // We use cmpxchg_ptr instead of regular assignment here because the user
   // may fork a bunch of threads, and we need them all to see the same state.
   void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
   guarantee(observed == NULL, "no races in this sequential code");
 }
 void nmethod::oops_do_marking_epilogue() {
   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
   nmethod* cur = _oops_do_mark_nmethods;
   while (cur != NMETHOD_SENTINEL) {
     assert(cur != NULL, "not NULL-terminated");
     nmethod* next = cur->_oops_do_mark_link;
     cur->_oops_do_mark_link = NULL;
     cur->verify_oop_relocations();
     NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
     cur = next;
   }
   void* required = _oops_do_mark_nmethods;
   void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
   guarantee(observed == required, "no races in this sequential code");
   NOT_PRODUCT(if (TraceScavenge)  tty->print_cr("oops_do_marking_epilogue]"));
 }
 class DetectScavengeRoot: public OopClosure {
   bool     _detected_scavenge_root;
 public:
   DetectScavengeRoot() : _detected_scavenge_root(false)
   { NOT_PRODUCT(_print_nm = NULL); }
   bool detected_scavenge_root() { return _detected_scavenge_root; }
   virtual void do_oop(oop* p) {
     if ((*p) != NULL && (*p)->is_scavengable()) {
       NOT_PRODUCT(maybe_print(p));
       _detected_scavenge_root = true;
     }
   }
   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 #ifndef PRODUCT
   nmethod* _print_nm;
   void maybe_print(oop* p) {
     if (_print_nm == NULL)  return;
     if (!_detected_scavenge_root)  _print_nm->print_on(tty, "new scavenge root");
     tty->print_cr(""PTR_FORMAT"[offset=%d] detected scavengable oop "PTR_FORMAT" (found at "PTR_FORMAT")",
                   _print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
                   (void *)(*p), (intptr_t)p);
     (*p)->print();
   }
 #endif //PRODUCT
 };
 bool nmethod::detect_scavenge_root_oops() {
   DetectScavengeRoot detect_scavenge_root;
   NOT_PRODUCT(if (TraceScavenge)  detect_scavenge_root._print_nm = this);
   oops_do(&detect_scavenge_root);
   return detect_scavenge_root.detected_scavenge_root();
 }
 // Method that knows how to preserve outgoing arguments at call. This method must be
 // called with a frame corresponding to a Java invoke
 void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
 #ifndef SHARK
   if (!method()->is_native()) {
     SimpleScopeDesc ssd(this, fr.pc());
     Bytecode_invoke call(ssd.method(), ssd.bci());
     bool has_receiver = call.has_receiver();
     bool has_appendix = call.has_appendix();
     Symbol* signature = call.signature();
     fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
   }
 #endif // !SHARK
 }
 oop nmethod::embeddedOop_at(u_char* p) {
   RelocIterator iter(this, p, p + 1);
   while (iter.next())
     if (iter.type() == relocInfo::oop_type) {
       return iter.oop_reloc()->oop_value();
     }
   return NULL;
 }
 inline bool includes(void* p, void* from, void* to) {
   return from <= p && p < to;
 }
 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
   assert(count >= 2, "must be sentinel values, at least");
 #ifdef ASSERT
   // must be sorted and unique; we do a binary search in find_pc_desc()
   int prev_offset = pcs[0].pc_offset();
   assert(prev_offset == PcDesc::lower_offset_limit,
          "must start with a sentinel");
   for (int i = 1; i < count; i++) {
     int this_offset = pcs[i].pc_offset();
     assert(this_offset > prev_offset, "offsets must be sorted");
     prev_offset = this_offset;
   }
   assert(prev_offset == PcDesc::upper_offset_limit,
          "must end with a sentinel");
 #endif //ASSERT
   // Search for MethodHandle invokes and tag the nmethod.
   for (int i = 0; i < count; i++) {
     if (pcs[i].is_method_handle_invoke()) {
       set_has_method_handle_invokes(true);
       break;
     }
   }
   assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
   int size = count * sizeof(PcDesc);
   assert(scopes_pcs_size() >= size, "oob");
   memcpy(scopes_pcs_begin(), pcs, size);
   // Adjust the final sentinel downward.
   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
   last_pc->set_pc_offset(content_size() + 1);
   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
     // Fill any rounding gaps with copies of the last record.
     last_pc[1] = last_pc[0];
   }
   // The following assert could fail if sizeof(PcDesc) is not
   // an integral multiple of oopSize (the rounding term).
   // If it fails, change the logic to always allocate a multiple
   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
 }
 void nmethod::copy_scopes_data(u_char* buffer, int size) {
   assert(scopes_data_size() >= size, "oob");
   memcpy(scopes_data_begin(), buffer, size);
 }
 #ifdef ASSERT
 static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
   PcDesc* lower = nm->scopes_pcs_begin();
   PcDesc* upper = nm->scopes_pcs_end();
   lower += 1; // exclude initial sentinel
   PcDesc* res = NULL;
   for (PcDesc* p = lower; p < upper; p++) {
     NOT_PRODUCT(--nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
     if (match_desc(p, pc_offset, approximate)) {
       if (res == NULL)
         res = p;
       else
         res = (PcDesc*) badAddress;
     }
   }
   return res;
 }
 #endif
 // Finds a PcDesc with real-pc equal to "pc"
 PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
   address base_address = code_begin();
   if ((pc < base_address) ||
       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
     return NULL;  // PC is wildly out of range
   }
   int pc_offset = (int) (pc - base_address);
   // Check the PcDesc cache if it contains the desired PcDesc
   // (This as an almost 100% hit rate.)
   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
   if (res != NULL) {
     assert(res == linear_search(this, pc_offset, approximate), "cache ok");
     return res;
   }
   // Fallback algorithm: quasi-linear search for the PcDesc
   // Find the last pc_offset less than the given offset.
   // The successor must be the required match, if there is a match at all.
   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
   PcDesc* lower = scopes_pcs_begin();
   PcDesc* upper = scopes_pcs_end();
   upper -= 1; // exclude final sentinel
   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
 #define assert_LU_OK \
   /* invariant on lower..upper during the following search: */ \
   assert(lower->pc_offset() <  pc_offset, "sanity"); \
   assert(upper->pc_offset() >= pc_offset, "sanity")
   assert_LU_OK;
   // Use the last successful return as a split point.
   PcDesc* mid = _pc_desc_cache.last_pc_desc();
   NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
   if (mid->pc_offset() < pc_offset) {
     lower = mid;
   } else {
     upper = mid;
   }
   // Take giant steps at first (4096, then 256, then 16, then 1)
   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
   const int RADIX = (1 << LOG2_RADIX);
   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
     while ((mid = lower + step) < upper) {
       assert_LU_OK;
       NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
       if (mid->pc_offset() < pc_offset) {
         lower = mid;
       } else {
         upper = mid;
         break;
       }
     }
     assert_LU_OK;
   }
   // Sneak up on the value with a linear search of length ~16.
   while (true) {
     assert_LU_OK;
     mid = lower + 1;
     NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
     if (mid->pc_offset() < pc_offset) {
       lower = mid;
     } else {
       upper = mid;
       break;
     }
   }
 #undef assert_LU_OK
   if (match_desc(upper, pc_offset, approximate)) {
     assert(upper == linear_search(this, pc_offset, approximate), "search ok");
     _pc_desc_cache.add_pc_desc(upper);
     return upper;
   } else {
     assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
     return NULL;
   }
 }
 bool nmethod::check_all_dependencies() {
   bool found_check = false;
   // wholesale check of all dependencies
   for (Dependencies::DepStream deps(this); deps.next(); ) {
     if (deps.check_dependency() != NULL) {
       found_check = true;
       NOT_DEBUG(break);
     }
   }
   return found_check;  // tell caller if we found anything
 }
 bool nmethod::check_dependency_on(DepChange& changes) {
   // What has happened:
   // 1) a new class dependee has been added
   // 2) dependee and all its super classes have been marked
   bool found_check = false;  // set true if we are upset
   for (Dependencies::DepStream deps(this); deps.next(); ) {
     // Evaluate only relevant dependencies.
     if (deps.spot_check_dependency_at(changes) != NULL) {
       found_check = true;
       NOT_DEBUG(break);
     }
   }
   return found_check;
 }
 bool nmethod::is_evol_dependent_on(Klass* dependee) {
   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
   Array<Method*>* dependee_methods = dependee_ik->methods();
   for (Dependencies::DepStream deps(this); deps.next(); ) {
     if (deps.type() == Dependencies::evol_method) {
       Method* method = deps.method_argument(0);
       for (int j = 0; j < dependee_methods->length(); j++) {
         if (dependee_methods->at(j) == method) {
           // RC_TRACE macro has an embedded ResourceMark
           RC_TRACE(0x01000000,
             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
             _method->method_holder()->external_name(),
             _method->name()->as_C_string(),
             _method->signature()->as_C_string(), compile_id(),
             method->method_holder()->external_name(),
             method->name()->as_C_string(),
             method->signature()->as_C_string()));
           if (TraceDependencies || LogCompilation)
             deps.log_dependency(dependee);
           return true;
         }
       }
     }
   }
   return false;
 }
 // Called from mark_for_deoptimization, when dependee is invalidated.
 bool nmethod::is_dependent_on_method(Method* dependee) {
   for (Dependencies::DepStream deps(this); deps.next(); ) {
     if (deps.type() != Dependencies::evol_method)
       continue;
     Method* method = deps.method_argument(0);
     if (method == dependee) return true;
   }
   return false;
 }
 bool nmethod::is_patchable_at(address instr_addr) {
   assert(insts_contains(instr_addr), "wrong nmethod used");
   if (is_zombie()) {
     // a zombie may never be patched
     return false;
   }
   return true;
 }
 address nmethod::continuation_for_implicit_exception(address pc) {
   // Exception happened outside inline-cache check code => we are inside
   // an active nmethod => use cpc to determine a return address
   int exception_offset = pc - code_begin();
   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
 #ifdef ASSERT
   if (cont_offset == 0) {
     Thread* thread = ThreadLocalStorage::get_thread_slow();
     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
     HandleMark hm(thread);
     ResourceMark rm(thread);
     CodeBlob* cb = CodeCache::find_blob(pc);
     assert(cb != NULL && cb == this, "");
     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
     print();
     method()->print_codes();
     print_code();
     print_pcs();
   }
 #endif
   if (cont_offset == 0) {
     // Let the normal error handling report the exception
     return NULL;
   }
   return code_begin() + cont_offset;
 }
 void nmethod_init() {
   // make sure you didn't forget to adjust the filler fields
   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
 }
 //-------------------------------------------------------------------------------------------
 // QQQ might we make this work from a frame??
 nmethodLocker::nmethodLocker(address pc) {
   CodeBlob* cb = CodeCache::find_blob(pc);
   guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
   _nm = (nmethod*)cb;
   lock_nmethod(_nm);
 }
 // Only JvmtiDeferredEvent::compiled_method_unload_event()
 // should pass zombie_ok == true.
 void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
   if (nm == NULL)  return;
   Atomic::inc(&nm->_lock_count);
   guarantee(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
 }
 void nmethodLocker::unlock_nmethod(nmethod* nm) {
   if (nm == NULL)  return;
   Atomic::dec(&nm->_lock_count);
   guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
 }
 // -----------------------------------------------------------------------------
 // nmethod::get_deopt_original_pc
 //
 // Return the original PC for the given PC if:
 // (a) the given PC belongs to a nmethod and
 // (b) it is a deopt PC
 address nmethod::get_deopt_original_pc(const frame* fr) {
   if (fr->cb() == NULL)  return NULL;
   nmethod* nm = fr->cb()->as_nmethod_or_null();
   if (nm != NULL && nm->is_deopt_pc(fr->pc()))
     return nm->get_original_pc(fr);
   return NULL;
 }
 // -----------------------------------------------------------------------------
 // MethodHandle
 bool nmethod::is_method_handle_return(address return_pc) {
   if (!has_method_handle_invokes())  return false;
   PcDesc* pd = pc_desc_at(return_pc);
   if (pd == NULL)
     return false;
   return pd->is_method_handle_invoke();
 }
 // -----------------------------------------------------------------------------
 // Verification
 class VerifyOopsClosure: public OopClosure {
   nmethod* _nm;
   bool     _ok;
 public:
   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
   bool ok() { return _ok; }
   virtual void do_oop(oop* p) {
     if ((*p) == NULL || (*p)->is_oop())  return;
     if (_ok) {
       _nm->print_nmethod(true);
       _ok = false;
     }
     tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
                   (void *)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
   }
   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 };
 void nmethod::verify() {
   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
   // seems odd.
   if (is_zombie() || is_not_entrant() || is_unloaded())
     return;
   // Make sure all the entry points are correctly aligned for patching.
   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
   // assert(method()->is_oop(), "must be valid");
   ResourceMark rm;
   if (!CodeCache::contains(this)) {
     fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
   }
   if(is_native_method() )
     return;
   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
   if (nm != this) {
     fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
                   this));
   }
   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
     if (! p->verify(this)) {
       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
     }
   }
   VerifyOopsClosure voc(this);
   oops_do(&voc);
   assert(voc.ok(), "embedded oops must be OK");
   verify_scavenge_root_oops();
   verify_scopes();
 }
 void nmethod::verify_interrupt_point(address call_site) {
   // Verify IC only when nmethod installation is finished.
   bool is_installed = (method()->code() == this) // nmethod is in state 'in_use' and installed
                       || !this->is_in_use();     // nmethod is installed, but not in 'in_use' state
   if (is_installed) {
     Thread *cur = Thread::current();
     if (CompiledIC_lock->owner() == cur ||
         ((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
          SafepointSynchronize::is_at_safepoint())) {
       CompiledIC_at(this, call_site);
       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
     } else {
       MutexLocker ml_verify (CompiledIC_lock);
       CompiledIC_at(this, call_site);
     }
   }
   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
   assert(pd != NULL, "PcDesc must exist");
   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
                                      pd->obj_decode_offset(), pd->should_reexecute(),
                                      pd->return_oop());
        !sd->is_top(); sd = sd->sender()) {
     sd->verify();
   }
 }
 void nmethod::verify_scopes() {
   if( !method() ) return;       // Runtime stubs have no scope
   if (method()->is_native()) return; // Ignore stub methods.
   // iterate through all interrupt point
   // and verify the debug information is valid.
   RelocIterator iter((nmethod*)this);
   while (iter.next()) {
     address stub = NULL;
     switch (iter.type()) {
       case relocInfo::virtual_call_type:
         verify_interrupt_point(iter.addr());
         break;
       case relocInfo::opt_virtual_call_type:
         stub = iter.opt_virtual_call_reloc()->static_stub();
         verify_interrupt_point(iter.addr());
         break;
       case relocInfo::static_call_type:
         stub = iter.static_call_reloc()->static_stub();
         //verify_interrupt_point(iter.addr());
         break;
       case relocInfo::runtime_call_type:
         address destination = iter.reloc()->value();
         // Right now there is no way to find out which entries support
         // an interrupt point.  It would be nice if we had this
         // information in a table.
         break;
     }
     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
   }
 }
 // -----------------------------------------------------------------------------
 // Non-product code
 #ifndef PRODUCT
 class DebugScavengeRoot: public OopClosure {
   nmethod* _nm;
   bool     _ok;
 public:
   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
   bool ok() { return _ok; }
   virtual void do_oop(oop* p) {
     if ((*p) == NULL || !(*p)->is_scavengable())  return;
     if (_ok) {
       _nm->print_nmethod(true);
       _ok = false;
     }
     tty->print_cr("*** scavengable oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
                   (void *)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
     (*p)->print();
   }
   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 };
 void nmethod::verify_scavenge_root_oops() {
   if (UseG1GC) {
     return;
   }
   if (!on_scavenge_root_list()) {
     // Actually look inside, to verify the claim that it's clean.
     DebugScavengeRoot debug_scavenge_root(this);
     oops_do(&debug_scavenge_root);
     if (!debug_scavenge_root.ok())
       fatal("found an unadvertised bad scavengable oop in the code cache");
   }
   assert(scavenge_root_not_marked(), "");
 }
 #endif // PRODUCT
 // Printing operations
 void nmethod::print() const {
   ResourceMark rm;
   ttyLocker ttyl;   // keep the following output all in one block
   tty->print("Compiled method ");
   if (is_compiled_by_c1()) {
     tty->print("(c1) ");
   } else if (is_compiled_by_c2()) {
     tty->print("(c2) ");
   } else if (is_compiled_by_shark()) {
     tty->print("(shark) ");
   } else {
     tty->print("(nm) ");
   }
   print_on(tty, NULL);
   if (WizardMode) {
     tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
     tty->print(" for method " INTPTR_FORMAT , (address)method());
     tty->print(" { ");
     if (is_in_use())      tty->print("in_use ");
     if (is_not_entrant()) tty->print("not_entrant ");
     if (is_zombie())      tty->print("zombie ");
     if (is_unloaded())    tty->print("unloaded ");
     if (on_scavenge_root_list())  tty->print("scavenge_root ");
     tty->print_cr("}:");
   }
   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               (address)this,
                                               (address)this + size(),
                                               size());
   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               relocation_begin(),
                                               relocation_end(),
                                               relocation_size());
   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               consts_begin(),
                                               consts_end(),
                                               consts_size());
   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               insts_begin(),
                                               insts_end(),
                                               insts_size());
   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               stub_begin(),
                                               stub_end(),
                                               stub_size());
   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               oops_begin(),
                                               oops_end(),
                                               oops_size());
   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               metadata_begin(),
                                               metadata_end(),
                                               metadata_size());
   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               scopes_data_begin(),
                                               scopes_data_end(),
                                               scopes_data_size());
   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               scopes_pcs_begin(),
                                               scopes_pcs_end(),
                                               scopes_pcs_size());
   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               dependencies_begin(),
                                               dependencies_end(),
                                               dependencies_size());
   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               handler_table_begin(),
                                               handler_table_end(),
                                               handler_table_size());
   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
                                               nul_chk_table_begin(),
                                               nul_chk_table_end(),
                                               nul_chk_table_size());
 }
 void nmethod::print_code() {
   HandleMark hm;
   ResourceMark m;
   Disassembler::decode(this);
 }
 #ifndef PRODUCT
 void nmethod::print_scopes() {
   // Find the first pc desc for all scopes in the code and print it.
   ResourceMark rm;
   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
       continue;
     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
     sd->print_on(tty, p);
   }
 }
 void nmethod::print_dependencies() {
   ResourceMark rm;
   ttyLocker ttyl;   // keep the following output all in one block
   tty->print_cr("Dependencies:");
   for (Dependencies::DepStream deps(this); deps.next(); ) {
     deps.print_dependency();
     Klass* ctxk = deps.context_type();
     if (ctxk != NULL) {
       if (ctxk->oop_is_instance() && ((InstanceKlass*)ctxk)->is_dependent_nmethod(this)) {
         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
       }
     }
     deps.log_dependency();  // put it into the xml log also
   }
 }
 void nmethod::print_relocations() {
   ResourceMark m;       // in case methods get printed via the debugger
   tty->print_cr("relocations:");
   RelocIterator iter(this);
   iter.print();
   if (UseRelocIndex) {
     jint* index_end   = (jint*)relocation_end() - 1;
     jint  index_size  = *index_end;
     jint* index_start = (jint*)( (address)index_end - index_size );
     tty->print_cr("    index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
     if (index_size > 0) {
       jint* ip;
       for (ip = index_start; ip+2 <= index_end; ip += 2)
         tty->print_cr("  (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
                       ip[0],
                       ip[1],
                       header_end()+ip[0],
                       relocation_begin()-1+ip[1]);
       for (; ip < index_end; ip++)
         tty->print_cr("  (%d ?)", ip[0]);
       tty->print_cr("          @" INTPTR_FORMAT ": index_size=%d", ip, *ip);
       ip++;
       tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
     }
   }
 }
 void nmethod::print_pcs() {
   ResourceMark m;       // in case methods get printed via debugger
   tty->print_cr("pc-bytecode offsets:");
   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
     p->print(this);
   }
 }
 #endif // PRODUCT
 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
   RelocIterator iter(this, begin, end);
   bool have_one = false;
   while (iter.next()) {
     have_one = true;
     switch (iter.type()) {
         case relocInfo::none:                  return "no_reloc";
         case relocInfo::oop_type: {
           stringStream st;
           oop_Relocation* r = iter.oop_reloc();
           oop obj = r->oop_value();
           st.print("oop(");
           if (obj == NULL) st.print("NULL");
           else obj->print_value_on(&st);
           st.print(")");
           return st.as_string();
         }
         case relocInfo::metadata_type: {
           stringStream st;
           metadata_Relocation* r = iter.metadata_reloc();
           Metadata* obj = r->metadata_value();
           st.print("metadata(");
           if (obj == NULL) st.print("NULL");
           else obj->print_value_on(&st);
           st.print(")");
           return st.as_string();
         }
         case relocInfo::virtual_call_type:     return "virtual_call";
         case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
         case relocInfo::static_call_type:      return "static_call";
         case relocInfo::static_stub_type:      return "static_stub";
         case relocInfo::runtime_call_type:     return "runtime_call";
         case relocInfo::external_word_type:    return "external_word";
         case relocInfo::internal_word_type:    return "internal_word";
         case relocInfo::section_word_type:     return "section_word";
         case relocInfo::poll_type:             return "poll";
         case relocInfo::poll_return_type:      return "poll_return";
         case relocInfo::type_mask:             return "type_bit_mask";
     }
   }
   return have_one ? "other" : NULL;
 }
 // Return a the last scope in (begin..end]
 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
   PcDesc* p = pc_desc_near(begin+1);
   if (p != NULL && p->real_pc(this) <= end) {
     return new ScopeDesc(this, p->scope_decode_offset(),
                          p->obj_decode_offset(), p->should_reexecute(),
                          p->return_oop());
   }
   return NULL;
 }
 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
   if (block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
   if (has_method_handle_invokes())
     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
   if (block_begin == entry_point()) {
     methodHandle m = method();
     if (m.not_null()) {
       stream->print("  # ");
       m->print_value_on(stream);
       stream->cr();
     }
     if (m.not_null() && !is_osr_method()) {
       ResourceMark rm;
       int sizeargs = m->size_of_parameters();
       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
       {
         int sig_index = 0;
         if (!m->is_static())
           sig_bt[sig_index++] = T_OBJECT; // 'this'
         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
           BasicType t = ss.type();
           sig_bt[sig_index++] = t;
           if (type2size[t] == 2) {
             sig_bt[sig_index++] = T_VOID;
           } else {
             assert(type2size[t] == 1, "size is 1 or 2");
           }
         }
         assert(sig_index == sizeargs, "");
       }
       const char* spname = "sp"; // make arch-specific?
       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
       int stack_slot_offset = this->frame_size() * wordSize;
       int tab1 = 14, tab2 = 24;
       int sig_index = 0;
       int arg_index = (m->is_static() ? 0 : -1);
       bool did_old_sp = false;
       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
         bool at_this = (arg_index == -1);
         bool at_old_sp = false;
         BasicType t = (at_this ? T_OBJECT : ss.type());
         assert(t == sig_bt[sig_index], "sigs in sync");
         if (at_this)
           stream->print("  # this: ");
         else
           stream->print("  # parm%d: ", arg_index);
         stream->move_to(tab1);
         VMReg fst = regs[sig_index].first();
         VMReg snd = regs[sig_index].second();
         if (fst->is_reg()) {
           stream->print("%s", fst->name());
           if (snd->is_valid())  {
             stream->print(":%s", snd->name());
           }
         } else if (fst->is_stack()) {
           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
           if (offset == stack_slot_offset)  at_old_sp = true;
           stream->print("[%s+0x%x]", spname, offset);
         } else {
           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
         }
         stream->print(" ");
         stream->move_to(tab2);
         stream->print("= ");
         if (at_this) {
           m->method_holder()->print_value_on(stream);
         } else {
           bool did_name = false;
           if (!at_this && ss.is_object()) {
             Symbol* name = ss.as_symbol_or_null();
             if (name != NULL) {
               name->print_value_on(stream);
               did_name = true;
             }
           }
           if (!did_name)
             stream->print("%s", type2name(t));
         }
         if (at_old_sp) {
           stream->print("  (%s of caller)", spname);
           did_old_sp = true;
         }
         stream->cr();
         sig_index += type2size[t];
         arg_index += 1;
         if (!at_this)  ss.next();
       }
       if (!did_old_sp) {
         stream->print("  # ");
         stream->move_to(tab1);
         stream->print("[%s+0x%x]", spname, stack_slot_offset);
         stream->print("  (%s of caller)", spname);
         stream->cr();
       }
     }
   }
 }
 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
   // First, find an oopmap in (begin, end].
   // We use the odd half-closed interval so that oop maps and scope descs
   // which are tied to the byte after a call are printed with the call itself.
   address base = code_begin();
   OopMapSet* oms = oop_maps();
   if (oms != NULL) {
     for (int i = 0, imax = oms->size(); i < imax; i++) {
       OopMap* om = oms->at(i);
       address pc = base + om->offset();
       if (pc > begin) {
         if (pc <= end) {
           st->move_to(column);
           st->print("; ");
           om->print_on(st);
         }
         break;
       }
     }
   }
   // Print any debug info present at this pc.
   ScopeDesc* sd  = scope_desc_in(begin, end);
   if (sd != NULL) {
     st->move_to(column);
     if (sd->bci() == SynchronizationEntryBCI) {
       st->print(";*synchronization entry");
     } else {
       if (sd->method() == NULL) {
         st->print("method is NULL");
       } else if (sd->method()->is_native()) {
         st->print("method is native");
       } else {
         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
         st->print(";*%s", Bytecodes::name(bc));
         switch (bc) {
         case Bytecodes::_invokevirtual:
         case Bytecodes::_invokespecial:
         case Bytecodes::_invokestatic:
         case Bytecodes::_invokeinterface:
           {
             Bytecode_invoke invoke(sd->method(), sd->bci());
             st->print(" ");
             if (invoke.name() != NULL)
               invoke.name()->print_symbol_on(st);
             else
               st->print("<UNKNOWN>");
             break;
           }
         case Bytecodes::_getfield:
         case Bytecodes::_putfield:
         case Bytecodes::_getstatic:
         case Bytecodes::_putstatic:
           {
             Bytecode_field field(sd->method(), sd->bci());
             st->print(" ");
             if (field.name() != NULL)
               field.name()->print_symbol_on(st);
             else
               st->print("<UNKNOWN>");
           }
         }
       }
     }
     // Print all scopes
     for (;sd != NULL; sd = sd->sender()) {
       st->move_to(column);
       st->print("; -");
       if (sd->method() == NULL) {
         st->print("method is NULL");
       } else {
         sd->method()->print_short_name(st);
       }
       int lineno = sd->method()->line_number_from_bci(sd->bci());
       if (lineno != -1) {
         st->print("@%d (line %d)", sd->bci(), lineno);
       } else {
         st->print("@%d", sd->bci());
       }
       st->cr();
     }
   }
   // Print relocation information
   const char* str = reloc_string_for(begin, end);
   if (str != NULL) {
     if (sd != NULL) st->cr();
     st->move_to(column);
     st->print(";   {%s}", str);
   }
   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
   if (cont_offset != 0) {
     st->move_to(column);
     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
   }
 }
 #ifndef PRODUCT
 void nmethod::print_value_on(outputStream* st) const {
   st->print("nmethod");
   print_on(st, NULL);
 }
 void nmethod::print_calls(outputStream* st) {
   RelocIterator iter(this);
   while (iter.next()) {
     switch (iter.type()) {
     case relocInfo::virtual_call_type:
     case relocInfo::opt_virtual_call_type: {
       VerifyMutexLocker mc(CompiledIC_lock);
       CompiledIC_at(&iter)->print();
       break;
     }
     case relocInfo::static_call_type:
       st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
       compiledStaticCall_at(iter.reloc())->print();
       break;
     }
   }
 }
 void nmethod::print_handler_table() {
   ExceptionHandlerTable(this).print();
 }
 void nmethod::print_nul_chk_table() {
   ImplicitExceptionTable(this).print(code_begin());
 }
 void nmethod::print_statistics() {
   ttyLocker ttyl;
   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
   nmethod_stats.print_native_nmethod_stats();
   nmethod_stats.print_nmethod_stats();
   DebugInformationRecorder::print_statistics();
   nmethod_stats.print_pc_stats();
   Dependencies::print_statistics();
   if (xtty != NULL)  xtty->tail("statistics");
 }
 #endif // PRODUCT

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/code/nmethod.cpp@5cece4584b8e (annotated)

src/share/vm/code/nmethod.cpp