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 /*

  * Copyright (c) 2003, 2012, 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

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  */

 #include "precompiled.hpp"

 #include "code/codeBlob.hpp"

 #include "code/codeCache.hpp"

 #include "code/scopeDesc.hpp"

 #include "code/vtableStubs.hpp"

 #include "memory/resourceArea.hpp"

 #include "oops/oop.inline.hpp"

 #include "prims/jvmtiCodeBlobEvents.hpp"

 #include "prims/jvmtiExport.hpp"

 #include "runtime/handles.hpp"

 #include "runtime/handles.inline.hpp"

 #include "runtime/vmThread.hpp"

 // Support class to collect a list of the non-nmethod CodeBlobs in

 // the CodeCache.

 //

 // This class actually creates a list of JvmtiCodeBlobDesc - each JvmtiCodeBlobDesc

 // describes a single CodeBlob in the CodeCache. Note that collection is

 // done to a static list - this is because CodeCache::blobs_do is defined

 // as void CodeCache::blobs_do(void f(CodeBlob* nm)) and hence requires

 // a C or static method.

 //

 // Usage :-

 //

 // CodeBlobCollector collector;

 //

 // collector.collect();

 // JvmtiCodeBlobDesc* blob = collector.first();

 // while (blob != NULL) {

 //   :

 //   blob = collector.next();

 // }

 //

 class CodeBlobCollector : StackObj {

  private:

   GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs;   // collected blobs

   int _pos;                                         // iterator position

   // used during a collection

   static GrowableArray<JvmtiCodeBlobDesc*>* _global_code_blobs;

   static void do_blob(CodeBlob* cb);

   static void do_vtable_stub(VtableStub* vs);

  public:

   CodeBlobCollector() {

     _code_blobs = NULL;

     _pos = -1;

   }

   ~CodeBlobCollector() {

     if (_code_blobs != NULL) {

       for (int i=0; i<_code_blobs->length(); i++) {

         FreeHeap(_code_blobs->at(i));

       }

       delete _code_blobs;

     }

   }

   // collect list of code blobs in the cache

   void collect();

   // iteration support - return first code blob

   JvmtiCodeBlobDesc* first() {

     assert(_code_blobs != NULL, "not collected");

     if (_code_blobs->length() == 0) {

       return NULL;

     }

     _pos = 0;

     return _code_blobs->at(0);

   }

   // iteration support - return next code blob

   JvmtiCodeBlobDesc* next() {

     assert(_pos >= 0, "iteration not started");

     if (_pos+1 >= _code_blobs->length()) {

       return NULL;

     }

     return _code_blobs->at(++_pos);

   }

 };

 // used during collection

 GrowableArray<JvmtiCodeBlobDesc*>* CodeBlobCollector::_global_code_blobs;

 // called for each CodeBlob in the CodeCache

 //

 // This function filters out nmethods as it is only interested in

 // other CodeBlobs. This function also filters out CodeBlobs that have

 // a duplicate starting address as previous blobs. This is needed to

 // handle the case where multiple stubs are generated into a single

 // BufferBlob.

 void CodeBlobCollector::do_blob(CodeBlob* cb) {

   // ignore nmethods

   if (cb->is_nmethod()) {

     return;

   }

   // exclude VtableStubs, which are processed separately

   if (cb->is_buffer_blob() && strcmp(cb->name(), "vtable chunks") == 0) {

     return;

   }

   // check if this starting address has been seen already - the

   // assumption is that stubs are inserted into the list before the

   // enclosing BufferBlobs.

   address addr = cb->code_begin();

   for (int i=0; i<_global_code_blobs->length(); i++) {

     JvmtiCodeBlobDesc* scb = _global_code_blobs->at(i);

     if (addr == scb->code_begin()) {

       return;

     }

   }

   // record the CodeBlob details as a JvmtiCodeBlobDesc

   JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(cb->name(), cb->code_begin(), cb->code_end());

   _global_code_blobs->append(scb);

 }

 // called for each VtableStub in VtableStubs

 void CodeBlobCollector::do_vtable_stub(VtableStub* vs) {

     JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(vs->is_vtable_stub() ? "vtable stub" : "itable stub",

                                                    vs->code_begin(), vs->code_end());

     _global_code_blobs->append(scb);

 }

 // collects a list of CodeBlobs in the CodeCache.

 //

 // The created list is growable array of JvmtiCodeBlobDesc - each one describes

 // a CodeBlob. Note that the list is static - this is because CodeBlob::blobs_do

 // requires a a C or static function so we can't use an instance function. This

 // isn't a problem as the iteration is serial anyway as we need the CodeCache_lock

 // to iterate over the code cache.

 //

 // Note that the CodeBlobs in the CodeCache will include BufferBlobs that may

 // contain multiple stubs. As a profiler is interested in the stubs rather than

 // the enclosing container we first iterate over the stub code descriptors so

 // that the stubs go into the list first. do_blob will then filter out the

 // enclosing blobs if the starting address of the enclosing blobs matches the

 // starting address of first stub generated in the enclosing blob.

 void CodeBlobCollector::collect() {

   assert_locked_or_safepoint(CodeCache_lock);

   assert(_global_code_blobs == NULL, "checking");

   // create the global list

   _global_code_blobs = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<JvmtiCodeBlobDesc*>(50,true);

   // iterate over the stub code descriptors and put them in the list first.

   int index = 0;

   StubCodeDesc* desc;

   while ((desc = StubCodeDesc::desc_for_index(++index)) != NULL) {

     _global_code_blobs->append(new JvmtiCodeBlobDesc(desc->name(), desc->begin(), desc->end()));

   }

   // Vtable stubs are not described with StubCodeDesc,

   // process them separately

   VtableStubs::vtable_stub_do(do_vtable_stub);

   // next iterate over all the non-nmethod code blobs and add them to

   // the list - as noted above this will filter out duplicates and

   // enclosing blobs.

   CodeCache::blobs_do(do_blob);

   // make the global list the instance list so that it can be used

   // for other iterations.

   _code_blobs = _global_code_blobs;

   _global_code_blobs = NULL;

 }

 // Generate a DYNAMIC_CODE_GENERATED event for each non-nmethod code blob.

 jvmtiError JvmtiCodeBlobEvents::generate_dynamic_code_events(JvmtiEnv* env) {

   CodeBlobCollector collector;

   // First collect all the code blobs.  This has to be done in a

   // single pass over the code cache with CodeCache_lock held because

   // there isn't any safe way to iterate over regular CodeBlobs since

   // they can be freed at any point.

   {

     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);

     collector.collect();

   }

   // iterate over the collected list and post an event for each blob

   JvmtiCodeBlobDesc* blob = collector.first();

   while (blob != NULL) {

     JvmtiExport::post_dynamic_code_generated(env, blob->name(), blob->code_begin(), blob->code_end());

     blob = collector.next();

   }

   return JVMTI_ERROR_NONE;

 }

 // Generate a COMPILED_METHOD_LOAD event for each nnmethod

 jvmtiError JvmtiCodeBlobEvents::generate_compiled_method_load_events(JvmtiEnv* env) {

   HandleMark hm;

   // Walk the CodeCache notifying for live nmethods.  The code cache

   // may be changing while this is happening which is ok since newly

   // created nmethod will notify normally and nmethods which are freed

   // can be safely skipped.

   MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);

   nmethod* current = CodeCache::first_nmethod();

   while (current != NULL) {

     // Only notify for live nmethods

     if (current->is_alive()) {

       // Lock the nmethod so it can't be freed

       nmethodLocker nml(current);

       // Don't hold the lock over the notify or jmethodID creation

       MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);

       current->get_and_cache_jmethod_id();

       JvmtiExport::post_compiled_method_load(current);

     }

     current = CodeCache::next_nmethod(current);

   }

   return JVMTI_ERROR_NONE;

 }

 // create a C-heap allocated address location map for an nmethod

 void JvmtiCodeBlobEvents::build_jvmti_addr_location_map(nmethod *nm,

                                                         jvmtiAddrLocationMap** map_ptr,

                                                         jint *map_length_ptr)

 {

   ResourceMark rm;

   jvmtiAddrLocationMap* map = NULL;

   jint map_length = 0;

   // Generate line numbers using PcDesc and ScopeDesc info

   methodHandle mh(nm->method());

   if (!mh->is_native()) {

     PcDesc *pcd;

     int pcds_in_method;

     pcds_in_method = (nm->scopes_pcs_end() - nm->scopes_pcs_begin());

     map = NEW_C_HEAP_ARRAY(jvmtiAddrLocationMap, pcds_in_method, mtInternal);

     address scopes_data = nm->scopes_data_begin();

     for( pcd = nm->scopes_pcs_begin(); pcd < nm->scopes_pcs_end(); ++pcd ) {

       ScopeDesc sc0(nm, pcd->scope_decode_offset(), pcd->should_reexecute(), pcd->return_oop());

       ScopeDesc *sd  = &sc0;

       while( !sd->is_top() ) { sd = sd->sender(); }

       int bci = sd->bci();

       if (bci != InvocationEntryBci) {

         assert(map_length < pcds_in_method, "checking");

         map[map_length].start_address = (const void*)pcd->real_pc(nm);

         map[map_length].location = bci;

         ++map_length;

       }

     }

   }

   *map_ptr = map;

   *map_length_ptr = map_length;

 }