src/share/vm/prims/jvmtiCodeBlobEvents.cpp

Thu, 15 Jul 2010 08:54:48 -0700

author
never
date
Thu, 15 Jul 2010 08:54:48 -0700
changeset 2004
a528509c992b
parent 1988
65b0c03b165d
child 2103
3e8fbc61cee8
permissions
-rw-r--r--

6968336: VM crash guarantee(!nm->is_zombie()) failed: cannot lock a zombie method
Reviewed-by: twisti

     1 /*
     2  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 # include "incls/_precompiled.incl"
    26 # include "incls/_jvmtiCodeBlobEvents.cpp.incl"
    28 // Support class to collect a list of the non-nmethod CodeBlobs in
    29 // the CodeCache.
    30 //
    31 // This class actually creates a list of JvmtiCodeBlobDesc - each JvmtiCodeBlobDesc
    32 // describes a single CodeBlob in the CodeCache. Note that collection is
    33 // done to a static list - this is because CodeCache::blobs_do is defined
    34 // as void CodeCache::blobs_do(void f(CodeBlob* nm)) and hence requires
    35 // a C or static method.
    36 //
    37 // Usage :-
    38 //
    39 // CodeBlobCollector collector;
    40 //
    41 // collector.collect();
    42 // JvmtiCodeBlobDesc* blob = collector.first();
    43 // while (blob != NULL) {
    44 //   :
    45 //   blob = collector.next();
    46 // }
    47 //
    49 class CodeBlobCollector : StackObj {
    50  private:
    51   GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs;   // collected blobs
    52   int _pos;                                         // iterator position
    54   // used during a collection
    55   static GrowableArray<JvmtiCodeBlobDesc*>* _global_code_blobs;
    56   static void do_blob(CodeBlob* cb);
    57  public:
    58   CodeBlobCollector() {
    59     _code_blobs = NULL;
    60     _pos = -1;
    61   }
    62   ~CodeBlobCollector() {
    63     if (_code_blobs != NULL) {
    64       for (int i=0; i<_code_blobs->length(); i++) {
    65         FreeHeap(_code_blobs->at(i));
    66       }
    67       delete _code_blobs;
    68     }
    69   }
    71   // collect list of code blobs in the cache
    72   void collect();
    74   // iteration support - return first code blob
    75   JvmtiCodeBlobDesc* first() {
    76     assert(_code_blobs != NULL, "not collected");
    77     if (_code_blobs->length() == 0) {
    78       return NULL;
    79     }
    80     _pos = 0;
    81     return _code_blobs->at(0);
    82   }
    84   // iteration support - return next code blob
    85   JvmtiCodeBlobDesc* next() {
    86     assert(_pos >= 0, "iteration not started");
    87     if (_pos+1 >= _code_blobs->length()) {
    88       return NULL;
    89     }
    90     return _code_blobs->at(++_pos);
    91   }
    93 };
    95 // used during collection
    96 GrowableArray<JvmtiCodeBlobDesc*>* CodeBlobCollector::_global_code_blobs;
    99 // called for each CodeBlob in the CodeCache
   100 //
   101 // This function filters out nmethods as it is only interested in
   102 // other CodeBlobs. This function also filters out CodeBlobs that have
   103 // a duplicate starting address as previous blobs. This is needed to
   104 // handle the case where multiple stubs are generated into a single
   105 // BufferBlob.
   107 void CodeBlobCollector::do_blob(CodeBlob* cb) {
   109   // ignore nmethods
   110   if (cb->is_nmethod()) {
   111     return;
   112   }
   114   // check if this starting address has been seen already - the
   115   // assumption is that stubs are inserted into the list before the
   116   // enclosing BufferBlobs.
   117   address addr = cb->instructions_begin();
   118   for (int i=0; i<_global_code_blobs->length(); i++) {
   119     JvmtiCodeBlobDesc* scb = _global_code_blobs->at(i);
   120     if (addr == scb->code_begin()) {
   121       return;
   122     }
   123   }
   125   // record the CodeBlob details as a JvmtiCodeBlobDesc
   126   JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(cb->name(), cb->instructions_begin(),
   127                                                  cb->instructions_end());
   128   _global_code_blobs->append(scb);
   129 }
   132 // collects a list of CodeBlobs in the CodeCache.
   133 //
   134 // The created list is growable array of JvmtiCodeBlobDesc - each one describes
   135 // a CodeBlob. Note that the list is static - this is because CodeBlob::blobs_do
   136 // requires a a C or static function so we can't use an instance function. This
   137 // isn't a problem as the iteration is serial anyway as we need the CodeCache_lock
   138 // to iterate over the code cache.
   139 //
   140 // Note that the CodeBlobs in the CodeCache will include BufferBlobs that may
   141 // contain multiple stubs. As a profiler is interested in the stubs rather than
   142 // the enclosing container we first iterate over the stub code descriptors so
   143 // that the stubs go into the list first. do_blob will then filter out the
   144 // enclosing blobs if the starting address of the enclosing blobs matches the
   145 // starting address of first stub generated in the enclosing blob.
   147 void CodeBlobCollector::collect() {
   148   assert_locked_or_safepoint(CodeCache_lock);
   149   assert(_global_code_blobs == NULL, "checking");
   151   // create the global list
   152   _global_code_blobs = new (ResourceObj::C_HEAP) GrowableArray<JvmtiCodeBlobDesc*>(50,true);
   154   // iterate over the stub code descriptors and put them in the list first.
   155   int index = 0;
   156   StubCodeDesc* desc;
   157   while ((desc = StubCodeDesc::desc_for_index(++index)) != NULL) {
   158     _global_code_blobs->append(new JvmtiCodeBlobDesc(desc->name(), desc->begin(), desc->end()));
   159   }
   161   // next iterate over all the non-nmethod code blobs and add them to
   162   // the list - as noted above this will filter out duplicates and
   163   // enclosing blobs.
   164   CodeCache::blobs_do(do_blob);
   166   // make the global list the instance list so that it can be used
   167   // for other iterations.
   168   _code_blobs = _global_code_blobs;
   169   _global_code_blobs = NULL;
   170 }
   173 // Generate a DYNAMIC_CODE_GENERATED event for each non-nmethod code blob.
   175 jvmtiError JvmtiCodeBlobEvents::generate_dynamic_code_events(JvmtiEnv* env) {
   176   CodeBlobCollector collector;
   178   // First collect all the code blobs.  This has to be done in a
   179   // single pass over the code cache with CodeCache_lock held because
   180   // there isn't any safe way to iterate over regular CodeBlobs since
   181   // they can be freed at any point.
   182   {
   183     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   184     collector.collect();
   185   }
   187   // iterate over the collected list and post an event for each blob
   188   JvmtiCodeBlobDesc* blob = collector.first();
   189   while (blob != NULL) {
   190     JvmtiExport::post_dynamic_code_generated(env, blob->name(), blob->code_begin(), blob->code_end());
   191     blob = collector.next();
   192   }
   193   return JVMTI_ERROR_NONE;
   194 }
   197 // Generate a COMPILED_METHOD_LOAD event for each nnmethod
   198 jvmtiError JvmtiCodeBlobEvents::generate_compiled_method_load_events(JvmtiEnv* env) {
   199   HandleMark hm;
   201   // Walk the CodeCache notifying for live nmethods.  The code cache
   202   // may be changing while this is happening which is ok since newly
   203   // created nmethod will notify normally and nmethods which are freed
   204   // can be safely skipped.
   205   MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   206   nmethod* current = CodeCache::first_nmethod();
   207   while (current != NULL) {
   208     // Only notify for live nmethods
   209     if (current->is_alive()) {
   210       // Lock the nmethod so it can't be freed
   211       nmethodLocker nml(current);
   213       // Don't hold the lock over the notify or jmethodID creation
   214       MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
   215       current->get_and_cache_jmethod_id();
   216       JvmtiExport::post_compiled_method_load(current);
   217     }
   218     current = CodeCache::next_nmethod(current);
   219   }
   220   return JVMTI_ERROR_NONE;
   221 }
   224 // create a C-heap allocated address location map for an nmethod
   225 void JvmtiCodeBlobEvents::build_jvmti_addr_location_map(nmethod *nm,
   226                                                         jvmtiAddrLocationMap** map_ptr,
   227                                                         jint *map_length_ptr)
   228 {
   229   ResourceMark rm;
   230   jvmtiAddrLocationMap* map = NULL;
   231   jint map_length = 0;
   234   // Generate line numbers using PcDesc and ScopeDesc info
   235   methodHandle mh(nm->method());
   237   if (!mh->is_native()) {
   238     PcDesc *pcd;
   239     int pcds_in_method;
   241     pcds_in_method = (nm->scopes_pcs_end() - nm->scopes_pcs_begin());
   242     map = NEW_C_HEAP_ARRAY(jvmtiAddrLocationMap, pcds_in_method);
   244     address scopes_data = nm->scopes_data_begin();
   245     for( pcd = nm->scopes_pcs_begin(); pcd < nm->scopes_pcs_end(); ++pcd ) {
   246       ScopeDesc sc0(nm, pcd->scope_decode_offset(), pcd->should_reexecute(), pcd->return_oop());
   247       ScopeDesc *sd  = &sc0;
   248       while( !sd->is_top() ) { sd = sd->sender(); }
   249       int bci = sd->bci();
   250       if (bci != InvocationEntryBci) {
   251         assert(map_length < pcds_in_method, "checking");
   252         map[map_length].start_address = (const void*)pcd->real_pc(nm);
   253         map[map_length].location = bci;
   254         ++map_length;
   255       }
   256     }
   257   }
   259   *map_ptr = map;
   260   *map_length_ptr = map_length;
   261 }

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