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