1.1 --- a/src/share/vm/prims/jvmtiCodeBlobEvents.cpp Tue Jun 29 16:09:57 2010 -0700
1.2 +++ b/src/share/vm/prims/jvmtiCodeBlobEvents.cpp Fri Jul 02 15:01:47 2010 -0700
1.3 @@ -1,5 +1,5 @@
1.4 /*
1.5 - * Copyright (c) 2003, 2009, Oracle and/or its affiliates. All rights reserved.
1.6 + * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
1.7 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.8 *
1.9 * This code is free software; you can redistribute it and/or modify it
1.10 @@ -118,34 +118,13 @@
1.11 for (int i=0; i<_global_code_blobs->length(); i++) {
1.12 JvmtiCodeBlobDesc* scb = _global_code_blobs->at(i);
1.13 if (addr == scb->code_begin()) {
1.14 + ShouldNotReachHere();
1.15 return;
1.16 }
1.17 }
1.18
1.19 - // we must name the CodeBlob - some CodeBlobs already have names :-
1.20 - // - stubs used by compiled code to call a (static) C++ runtime routine
1.21 - // - non-relocatable machine code such as the interpreter, stubroutines, etc.
1.22 - // - various singleton blobs
1.23 - //
1.24 - // others are unnamed so we create a name :-
1.25 - // - OSR adapter (interpreter frame that has been on-stack replaced)
1.26 - // - I2C and C2I adapters
1.27 - const char* name = NULL;
1.28 - if (cb->is_runtime_stub()) {
1.29 - name = ((RuntimeStub*)cb)->name();
1.30 - }
1.31 - if (cb->is_buffer_blob()) {
1.32 - name = ((BufferBlob*)cb)->name();
1.33 - }
1.34 - if (cb->is_deoptimization_stub() || cb->is_safepoint_stub()) {
1.35 - name = ((SingletonBlob*)cb)->name();
1.36 - }
1.37 - if (cb->is_uncommon_trap_stub() || cb->is_exception_stub()) {
1.38 - name = ((SingletonBlob*)cb)->name();
1.39 - }
1.40 -
1.41 // record the CodeBlob details as a JvmtiCodeBlobDesc
1.42 - JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(name, cb->instructions_begin(),
1.43 + JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(cb->name(), cb->instructions_begin(),
1.44 cb->instructions_end());
1.45 _global_code_blobs->append(scb);
1.46 }
1.47 @@ -197,7 +176,10 @@
1.48 jvmtiError JvmtiCodeBlobEvents::generate_dynamic_code_events(JvmtiEnv* env) {
1.49 CodeBlobCollector collector;
1.50
1.51 - // first collect all the code blobs
1.52 + // First collect all the code blobs. This has to be done in a
1.53 + // single pass over the code cache with CodeCache_lock held because
1.54 + // there isn't any safe way to iterate over regular CodeBlobs since
1.55 + // they can be freed at any point.
1.56 {
1.57 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1.58 collector.collect();
1.59 @@ -213,166 +195,28 @@
1.60 }
1.61
1.62
1.63 -// Support class to describe a nmethod in the CodeCache
1.64 -
1.65 -class nmethodDesc: public CHeapObj {
1.66 - private:
1.67 - jmethodID _jmethod_id;
1.68 - address _code_begin;
1.69 - address _code_end;
1.70 - jvmtiAddrLocationMap* _map;
1.71 - jint _map_length;
1.72 - public:
1.73 - nmethodDesc(jmethodID jmethod_id, address code_begin, address code_end,
1.74 - jvmtiAddrLocationMap* map, jint map_length) {
1.75 - _jmethod_id = jmethod_id;
1.76 - _code_begin = code_begin;
1.77 - _code_end = code_end;
1.78 - _map = map;
1.79 - _map_length = map_length;
1.80 - }
1.81 - jmethodID jmethod_id() const { return _jmethod_id; }
1.82 - address code_begin() const { return _code_begin; }
1.83 - address code_end() const { return _code_end; }
1.84 - jvmtiAddrLocationMap* map() const { return _map; }
1.85 - jint map_length() const { return _map_length; }
1.86 -};
1.87 -
1.88 -
1.89 -// Support class to collect a list of the nmethod CodeBlobs in
1.90 -// the CodeCache.
1.91 -//
1.92 -// Usage :-
1.93 -//
1.94 -// nmethodCollector collector;
1.95 -//
1.96 -// collector.collect();
1.97 -// JvmtiCodeBlobDesc* blob = collector.first();
1.98 -// while (blob != NULL) {
1.99 -// :
1.100 -// blob = collector.next();
1.101 -// }
1.102 -//
1.103 -class nmethodCollector : StackObj {
1.104 - private:
1.105 - GrowableArray<nmethodDesc*>* _nmethods; // collect nmethods
1.106 - int _pos; // iteration support
1.107 -
1.108 - // used during a collection
1.109 - static GrowableArray<nmethodDesc*>* _global_nmethods;
1.110 - static void do_nmethod(nmethod* nm);
1.111 - public:
1.112 - nmethodCollector() {
1.113 - _nmethods = NULL;
1.114 - _pos = -1;
1.115 - }
1.116 - ~nmethodCollector() {
1.117 - if (_nmethods != NULL) {
1.118 - for (int i=0; i<_nmethods->length(); i++) {
1.119 - nmethodDesc* blob = _nmethods->at(i);
1.120 - if (blob->map()!= NULL) {
1.121 - FREE_C_HEAP_ARRAY(jvmtiAddrLocationMap, blob->map());
1.122 - }
1.123 - }
1.124 - delete _nmethods;
1.125 - }
1.126 - }
1.127 -
1.128 - // collect list of nmethods in the cache
1.129 - void collect();
1.130 -
1.131 - // iteration support - return first code blob
1.132 - nmethodDesc* first() {
1.133 - assert(_nmethods != NULL, "not collected");
1.134 - if (_nmethods->length() == 0) {
1.135 - return NULL;
1.136 - }
1.137 - _pos = 0;
1.138 - return _nmethods->at(0);
1.139 - }
1.140 -
1.141 - // iteration support - return next code blob
1.142 - nmethodDesc* next() {
1.143 - assert(_pos >= 0, "iteration not started");
1.144 - if (_pos+1 >= _nmethods->length()) {
1.145 - return NULL;
1.146 - }
1.147 - return _nmethods->at(++_pos);
1.148 - }
1.149 -};
1.150 -
1.151 -// used during collection
1.152 -GrowableArray<nmethodDesc*>* nmethodCollector::_global_nmethods;
1.153 -
1.154 -
1.155 -// called for each nmethod in the CodeCache
1.156 -//
1.157 -// This function simply adds a descriptor for each nmethod to the global list.
1.158 -
1.159 -void nmethodCollector::do_nmethod(nmethod* nm) {
1.160 - // ignore zombies
1.161 - if (!nm->is_alive()) {
1.162 - return;
1.163 - }
1.164 -
1.165 - assert(nm->method() != NULL, "checking");
1.166 -
1.167 - // create the location map for the nmethod.
1.168 - jvmtiAddrLocationMap* map;
1.169 - jint map_length;
1.170 - JvmtiCodeBlobEvents::build_jvmti_addr_location_map(nm, &map, &map_length);
1.171 -
1.172 - // record the nmethod details
1.173 - nmethodDesc* snm = new nmethodDesc(nm->get_and_cache_jmethod_id(),
1.174 - nm->code_begin(),
1.175 - nm->code_end(),
1.176 - map,
1.177 - map_length);
1.178 - _global_nmethods->append(snm);
1.179 -}
1.180 -
1.181 -// collects a list of nmethod in the CodeCache.
1.182 -//
1.183 -// The created list is growable array of nmethodDesc - each one describes
1.184 -// a nmethod and includs its JVMTI address location map.
1.185 -
1.186 -void nmethodCollector::collect() {
1.187 - assert_locked_or_safepoint(CodeCache_lock);
1.188 - assert(_global_nmethods == NULL, "checking");
1.189 -
1.190 - // create the list
1.191 - _global_nmethods = new (ResourceObj::C_HEAP) GrowableArray<nmethodDesc*>(100,true);
1.192 -
1.193 - // any a descriptor for each nmethod to the list.
1.194 - CodeCache::nmethods_do(do_nmethod);
1.195 -
1.196 - // make the list the instance list
1.197 - _nmethods = _global_nmethods;
1.198 - _global_nmethods = NULL;
1.199 -}
1.200 -
1.201 // Generate a COMPILED_METHOD_LOAD event for each nnmethod
1.202 -
1.203 jvmtiError JvmtiCodeBlobEvents::generate_compiled_method_load_events(JvmtiEnv* env) {
1.204 HandleMark hm;
1.205 - nmethodCollector collector;
1.206
1.207 - // first collect all nmethods
1.208 - {
1.209 - MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1.210 - collector.collect();
1.211 - }
1.212 + // Walk the CodeCache notifying for live nmethods. The code cache
1.213 + // may be changing while this is happening which is ok since newly
1.214 + // created nmethod will notify normally and nmethods which are freed
1.215 + // can be safely skipped.
1.216 + MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1.217 + nmethod* current = CodeCache::first_nmethod();
1.218 + while (current != NULL) {
1.219 + // Lock the nmethod so it can't be freed
1.220 + nmethodLocker nml(current);
1.221
1.222 - // iterate over the list and post an event for each nmethod
1.223 - nmethodDesc* nm_desc = collector.first();
1.224 - while (nm_desc != NULL) {
1.225 - jmethodID mid = nm_desc->jmethod_id();
1.226 - assert(mid != NULL, "checking");
1.227 - JvmtiExport::post_compiled_method_load(env, mid,
1.228 - (jint)(nm_desc->code_end() - nm_desc->code_begin()),
1.229 - nm_desc->code_begin(), nm_desc->map_length(),
1.230 - nm_desc->map());
1.231 - nm_desc = collector.next();
1.232 + // Only notify for live nmethods
1.233 + if (current->is_alive()) {
1.234 + // Don't hold the lock over the notify or jmethodID creation
1.235 + MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1.236 + current->get_and_cache_jmethod_id();
1.237 + JvmtiExport::post_compiled_method_load(current);
1.238 + }
1.239 + current = CodeCache::next_nmethod(current);
1.240 }
1.241 return JVMTI_ERROR_NONE;
1.242 }
