1/* 2 * Copyright (c) 2003, 2012, 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 */ 24 25#include "precompiled.hpp" 26#include "code/codeBlob.hpp" 27#include "code/codeCache.hpp" 28#include "code/scopeDesc.hpp" 29#include "code/vtableStubs.hpp" 30#include "memory/resourceArea.hpp" 31#include "oops/oop.inline.hpp" 32#include "prims/jvmtiCodeBlobEvents.hpp" 33#include "prims/jvmtiExport.hpp" 34#include "runtime/handles.hpp" 35#include "runtime/handles.inline.hpp" 36#include "runtime/vmThread.hpp" 37 38// Support class to collect a list of the non-nmethod CodeBlobs in 39// the CodeCache. 40// 41// This class actually creates a list of JvmtiCodeBlobDesc - each JvmtiCodeBlobDesc 42// describes a single CodeBlob in the CodeCache. Note that collection is 43// done to a static list - this is because CodeCache::blobs_do is defined 44// as void CodeCache::blobs_do(void f(CodeBlob* nm)) and hence requires 45// a C or static method. 46// 47// Usage :- 48// 49// CodeBlobCollector collector; 50// 51// collector.collect(); 52// JvmtiCodeBlobDesc* blob = collector.first(); 53// while (blob != NULL) { 54// : 55// blob = collector.next(); 56// } 57// 58 59class CodeBlobCollector : StackObj { 60 private: 61 GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs; // collected blobs 62 int _pos; // iterator position 63 64 // used during a collection 65 static GrowableArray<JvmtiCodeBlobDesc*>* _global_code_blobs; 66 static void do_blob(CodeBlob* cb); 67 static void do_vtable_stub(VtableStub* vs); 68 public: 69 CodeBlobCollector() { 70 _code_blobs = NULL; 71 _pos = -1; 72 } 73 ~CodeBlobCollector() { 74 if (_code_blobs != NULL) { 75 for (int i=0; i<_code_blobs->length(); i++) { 76 FreeHeap(_code_blobs->at(i)); 77 } 78 delete _code_blobs; 79 } 80 } 81 82 // collect list of code blobs in the cache 83 void collect(); 84 85 // iteration support - return first code blob 86 JvmtiCodeBlobDesc* first() { 87 assert(_code_blobs != NULL, "not collected"); 88 if (_code_blobs->length() == 0) { 89 return NULL; 90 } 91 _pos = 0; 92 return _code_blobs->at(0); 93 } 94 95 // iteration support - return next code blob 96 JvmtiCodeBlobDesc* next() { 97 assert(_pos >= 0, "iteration not started"); 98 if (_pos+1 >= _code_blobs->length()) { 99 return NULL; 100 } 101 return _code_blobs->at(++_pos); 102 } 103 104}; 105 106// used during collection 107GrowableArray<JvmtiCodeBlobDesc*>* CodeBlobCollector::_global_code_blobs; 108 109 110// called for each CodeBlob in the CodeCache 111// 112// This function filters out nmethods as it is only interested in 113// other CodeBlobs. This function also filters out CodeBlobs that have 114// a duplicate starting address as previous blobs. This is needed to 115// handle the case where multiple stubs are generated into a single 116// BufferBlob. 117 118void CodeBlobCollector::do_blob(CodeBlob* cb) { 119 120 // ignore nmethods 121 if (cb->is_nmethod()) { 122 return; 123 } 124 // exclude VtableStubs, which are processed separately 125 if (cb->is_buffer_blob() && strcmp(cb->name(), "vtable chunks") == 0) { 126 return; 127 } 128 129 // check if this starting address has been seen already - the 130 // assumption is that stubs are inserted into the list before the 131 // enclosing BufferBlobs. 132 address addr = cb->code_begin(); 133 for (int i=0; i<_global_code_blobs->length(); i++) { 134 JvmtiCodeBlobDesc* scb = _global_code_blobs->at(i); 135 if (addr == scb->code_begin()) { 136 return; 137 } 138 } 139 140 // record the CodeBlob details as a JvmtiCodeBlobDesc 141 JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(cb->name(), cb->code_begin(), cb->code_end()); 142 _global_code_blobs->append(scb); 143} 144 145// called for each VtableStub in VtableStubs 146 147void CodeBlobCollector::do_vtable_stub(VtableStub* vs) { 148 JvmtiCodeBlobDesc* scb = new JvmtiCodeBlobDesc(vs->is_vtable_stub() ? "vtable stub" : "itable stub", 149 vs->code_begin(), vs->code_end()); 150 _global_code_blobs->append(scb); 151} 152 153// collects a list of CodeBlobs in the CodeCache. 154// 155// The created list is growable array of JvmtiCodeBlobDesc - each one describes 156// a CodeBlob. Note that the list is static - this is because CodeBlob::blobs_do 157// requires a a C or static function so we can't use an instance function. This 158// isn't a problem as the iteration is serial anyway as we need the CodeCache_lock 159// to iterate over the code cache. 160// 161// Note that the CodeBlobs in the CodeCache will include BufferBlobs that may 162// contain multiple stubs. As a profiler is interested in the stubs rather than 163// the enclosing container we first iterate over the stub code descriptors so 164// that the stubs go into the list first. do_blob will then filter out the 165// enclosing blobs if the starting address of the enclosing blobs matches the 166// starting address of first stub generated in the enclosing blob. 167 168void CodeBlobCollector::collect() { 169 assert_locked_or_safepoint(CodeCache_lock); 170 assert(_global_code_blobs == NULL, "checking"); 171 172 // create the global list 173 _global_code_blobs = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<JvmtiCodeBlobDesc*>(50,true); 174 175 // iterate over the stub code descriptors and put them in the list first. 176 for (StubCodeDesc* desc = StubCodeDesc::first(); desc != NULL; desc = StubCodeDesc::next(desc)) { 177 _global_code_blobs->append(new JvmtiCodeBlobDesc(desc->name(), desc->begin(), desc->end())); 178 } 179 180 // Vtable stubs are not described with StubCodeDesc, 181 // process them separately 182 VtableStubs::vtable_stub_do(do_vtable_stub); 183 184 // next iterate over all the non-nmethod code blobs and add them to 185 // the list - as noted above this will filter out duplicates and 186 // enclosing blobs. 187 CodeCache::blobs_do(do_blob); 188 189 // make the global list the instance list so that it can be used 190 // for other iterations. 191 _code_blobs = _global_code_blobs; 192 _global_code_blobs = NULL; 193} 194 195 196// Generate a DYNAMIC_CODE_GENERATED event for each non-nmethod code blob. 197 198jvmtiError JvmtiCodeBlobEvents::generate_dynamic_code_events(JvmtiEnv* env) { 199 CodeBlobCollector collector; 200 201 // First collect all the code blobs. This has to be done in a 202 // single pass over the code cache with CodeCache_lock held because 203 // there isn't any safe way to iterate over regular CodeBlobs since 204 // they can be freed at any point. 205 { 206 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 207 collector.collect(); 208 } 209 210 // iterate over the collected list and post an event for each blob 211 JvmtiCodeBlobDesc* blob = collector.first(); 212 while (blob != NULL) { 213 JvmtiExport::post_dynamic_code_generated(env, blob->name(), blob->code_begin(), blob->code_end()); 214 blob = collector.next(); 215 } 216 return JVMTI_ERROR_NONE; 217} 218 219 220// Generate a COMPILED_METHOD_LOAD event for each nnmethod 221jvmtiError JvmtiCodeBlobEvents::generate_compiled_method_load_events(JvmtiEnv* env) { 222 HandleMark hm; 223 224 // Walk the CodeCache notifying for live nmethods. The code cache 225 // may be changing while this is happening which is ok since newly 226 // created nmethod will notify normally and nmethods which are freed 227 // can be safely skipped. 228 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 229 // Iterate over non-profiled and profiled nmethods 230 NMethodIterator iter; 231 while(iter.next_alive()) { 232 nmethod* current = iter.method(); 233 // Lock the nmethod so it can't be freed 234 nmethodLocker nml(current); 235 236 // Don't hold the lock over the notify or jmethodID creation 237 MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 238 current->get_and_cache_jmethod_id(); 239 JvmtiExport::post_compiled_method_load(current); 240 } 241 return JVMTI_ERROR_NONE; 242} 243 244 245// create a C-heap allocated address location map for an nmethod 246void JvmtiCodeBlobEvents::build_jvmti_addr_location_map(nmethod *nm, 247 jvmtiAddrLocationMap** map_ptr, 248 jint *map_length_ptr) 249{ 250 ResourceMark rm; 251 jvmtiAddrLocationMap* map = NULL; 252 jint map_length = 0; 253 254 255 // Generate line numbers using PcDesc and ScopeDesc info 256 methodHandle mh(nm->method()); 257 258 if (!mh->is_native()) { 259 PcDesc *pcd; 260 int pcds_in_method; 261 262 pcds_in_method = (nm->scopes_pcs_end() - nm->scopes_pcs_begin()); 263 map = NEW_C_HEAP_ARRAY(jvmtiAddrLocationMap, pcds_in_method, mtInternal); 264 265 address scopes_data = nm->scopes_data_begin(); 266 for( pcd = nm->scopes_pcs_begin(); pcd < nm->scopes_pcs_end(); ++pcd ) { 267 ScopeDesc sc0(nm, pcd->scope_decode_offset(), pcd->should_reexecute(), pcd->rethrow_exception(), pcd->return_oop()); 268 ScopeDesc *sd = &sc0; 269 while( !sd->is_top() ) { sd = sd->sender(); } 270 int bci = sd->bci(); 271 if (bci != InvocationEntryBci) { 272 assert(map_length < pcds_in_method, "checking"); 273 map[map_length].start_address = (const void*)pcd->real_pc(nm); 274 map[map_length].location = bci; 275 ++map_length; 276 } 277 } 278 } 279 280 *map_ptr = map; 281 *map_length_ptr = map_length; 282} 283