jvmtiEnvThreadState.cpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 2003, 2006, 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 "incls/_precompiled.incl" 26# include "incls/_jvmtiEnvThreadState.cpp.incl" 27 28 29/////////////////////////////////////////////////////////////// 30// 31// class JvmtiFramePop 32// 33 34#ifndef PRODUCT 35void JvmtiFramePop::print() { 36 tty->print_cr("_frame_number=%d", _frame_number); 37} 38#endif 39 40 41/////////////////////////////////////////////////////////////// 42// 43// class JvmtiFramePops - private methods 44// 45 46void 47JvmtiFramePops::set(JvmtiFramePop& fp) { 48 if (_pops->find(fp.frame_number()) < 0) { 49 _pops->append(fp.frame_number()); 50 } 51} 52 53 54void 55JvmtiFramePops::clear(JvmtiFramePop& fp) { 56 assert(_pops->length() > 0, "No more frame pops"); 57 58 _pops->remove(fp.frame_number()); 59} 60 61 62int 63JvmtiFramePops::clear_to(JvmtiFramePop& fp) { 64 int cleared = 0; 65 int index = 0; 66 while (index < _pops->length()) { 67 JvmtiFramePop pop = JvmtiFramePop(_pops->at(index)); 68 if (pop.above_on_stack(fp)) { 69 _pops->remove_at(index); 70 ++cleared; 71 } else { 72 ++index; 73 } 74 } 75 return cleared; 76} 77 78 79/////////////////////////////////////////////////////////////// 80// 81// class JvmtiFramePops - public methods 82// 83 84JvmtiFramePops::JvmtiFramePops() { 85 _pops = new (ResourceObj::C_HEAP) GrowableArray<int> (2, true); 86} 87 88JvmtiFramePops::~JvmtiFramePops() { 89 // return memory to c_heap. 90 delete _pops; 91} 92 93 94#ifndef PRODUCT 95void JvmtiFramePops::print() { 96 ResourceMark rm; 97 98 int n = _pops->length(); 99 for (int i=0; i<n; i++) { 100 JvmtiFramePop fp = JvmtiFramePop(_pops->at(i)); 101 tty->print("%d: ", i); 102 fp.print(); 103 tty->print_cr(""); 104 } 105} 106#endif 107 108/////////////////////////////////////////////////////////////// 109// 110// class JvmtiEnvThreadState 111// 112// Instances of JvmtiEnvThreadState hang off of each JvmtiThreadState, 113// one per JvmtiEnv. 114// 115 116JvmtiEnvThreadState::JvmtiEnvThreadState(JavaThread *thread, JvmtiEnvBase *env) : 117 _event_enable() { 118 _thread = thread; 119 _env = (JvmtiEnv*)env; 120 _next = NULL; 121 _frame_pops = NULL; 122 _current_bci = 0; 123 _current_method_id = NULL; 124 _breakpoint_posted = false; 125 _single_stepping_posted = false; 126 _agent_thread_local_storage_data = NULL; 127} 128 129JvmtiEnvThreadState::~JvmtiEnvThreadState() { 130 delete _frame_pops; 131 _frame_pops = NULL; 132} 133 134// Given that a new (potential) event has come in, 135// maintain the current JVMTI location on a per-thread per-env basis 136// and use it to filter out duplicate events: 137// - instruction rewrites 138// - breakpoint followed by single step 139// - single step at a breakpoint 140void JvmtiEnvThreadState::compare_and_set_current_location(methodOop new_method, 141 address new_location, jvmtiEvent event) { 142 143 int new_bci = new_location - new_method->code_base(); 144 145 // The method is identified and stored as a jmethodID which is safe in this 146 // case because the class cannot be unloaded while a method is executing. 147 jmethodID new_method_id = new_method->jmethod_id(); 148 149 // the last breakpoint or single step was at this same location 150 if (_current_bci == new_bci && _current_method_id == new_method_id) { 151 switch (event) { 152 case JVMTI_EVENT_BREAKPOINT: 153 // Repeat breakpoint is complicated. If we previously posted a breakpoint 154 // event at this location and if we also single stepped at this location 155 // then we skip the duplicate breakpoint. 156 _breakpoint_posted = _breakpoint_posted && _single_stepping_posted; 157 break; 158 case JVMTI_EVENT_SINGLE_STEP: 159 // Repeat single step is easy: just don't post it again. 160 // If step is pending for popframe then it may not be 161 // a repeat step. The new_bci and method_id is same as current_bci 162 // and current method_id after pop and step for recursive calls. 163 // This has been handled by clearing the location 164 _single_stepping_posted = true; 165 break; 166 default: 167 assert(false, "invalid event value passed"); 168 break; 169 } 170 return; 171 } 172 173 set_current_location(new_method_id, new_bci); 174 _breakpoint_posted = false; 175 _single_stepping_posted = false; 176} 177 178 179JvmtiFramePops* JvmtiEnvThreadState::get_frame_pops() { 180#ifdef ASSERT 181 uint32_t debug_bits = 0; 182#endif 183 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 184 "frame pop data only accessible from same thread or while suspended"); 185 186 if (_frame_pops == NULL) { 187 _frame_pops = new JvmtiFramePops(); 188 assert(_frame_pops != NULL, "_frame_pops != NULL"); 189 } 190 return _frame_pops; 191} 192 193 194bool JvmtiEnvThreadState::has_frame_pops() { 195 return _frame_pops == NULL? false : (_frame_pops->length() > 0); 196} 197 198void JvmtiEnvThreadState::set_frame_pop(int frame_number) { 199#ifdef ASSERT 200 uint32_t debug_bits = 0; 201#endif 202 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 203 "frame pop data only accessible from same thread or while suspended"); 204 JvmtiFramePop fpop(frame_number); 205 JvmtiEventController::set_frame_pop(this, fpop); 206} 207 208 209void JvmtiEnvThreadState::clear_frame_pop(int frame_number) { 210#ifdef ASSERT 211 uint32_t debug_bits = 0; 212#endif 213 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 214 "frame pop data only accessible from same thread or while suspended"); 215 JvmtiFramePop fpop(frame_number); 216 JvmtiEventController::clear_frame_pop(this, fpop); 217} 218 219 220void JvmtiEnvThreadState::clear_to_frame_pop(int frame_number) { 221#ifdef ASSERT 222 uint32_t debug_bits = 0; 223#endif 224 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 225 "frame pop data only accessible from same thread or while suspended"); 226 JvmtiFramePop fpop(frame_number); 227 JvmtiEventController::clear_to_frame_pop(this, fpop); 228} 229 230 231bool JvmtiEnvThreadState::is_frame_pop(int cur_frame_number) { 232#ifdef ASSERT 233 uint32_t debug_bits = 0; 234#endif 235 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 236 "frame pop data only accessible from same thread or while suspended"); 237 if (!get_thread()->is_interp_only_mode() || _frame_pops == NULL) { 238 return false; 239 } 240 JvmtiFramePop fp(cur_frame_number); 241 return get_frame_pops()->contains(fp); 242} 243 244 245class VM_GetCurrentLocation : public VM_Operation { 246 private: 247 JavaThread *_thread; 248 jmethodID _method_id; 249 int _bci; 250 251 public: 252 VM_GetCurrentLocation(JavaThread *thread) { 253 _thread = thread; 254 } 255 VMOp_Type type() const { return VMOp_GetCurrentLocation; } 256 void doit() { 257 ResourceMark rmark; // _thread != Thread::current() 258 RegisterMap rm(_thread, false); 259 javaVFrame* vf = _thread->last_java_vframe(&rm); 260 assert(vf != NULL, "must have last java frame"); 261 methodOop method = vf->method(); 262 _method_id = method->jmethod_id(); 263 _bci = vf->bci(); 264 } 265 void get_current_location(jmethodID *method_id, int *bci) { 266 *method_id = _method_id; 267 *bci = _bci; 268 } 269}; 270 271void JvmtiEnvThreadState::reset_current_location(jvmtiEvent event_type, bool enabled) { 272 assert(event_type == JVMTI_EVENT_SINGLE_STEP || event_type == JVMTI_EVENT_BREAKPOINT, 273 "must be single-step or breakpoint event"); 274 275 // Current location is used to detect the following: 276 // 1) a breakpoint event followed by single-stepping to the same bci 277 // 2) single-step to a bytecode that will be transformed to a fast version 278 // We skip to avoid posting the duplicate single-stepping event. 279 280 // If single-stepping is disabled, clear current location so that 281 // single-stepping to the same method and bcp at a later time will be 282 // detected if single-stepping is enabled at that time (see 4388912). 283 284 // If single-stepping is enabled, set the current location to the 285 // current method and bcp. This covers the following type of case, 286 // e.g., the debugger stepi command: 287 // - bytecode single stepped 288 // - SINGLE_STEP event posted and SINGLE_STEP event disabled 289 // - SINGLE_STEP event reenabled 290 // - bytecode rewritten to fast version 291 292 // If breakpoint event is disabled, clear current location only if 293 // single-stepping is not enabled. Otherwise, keep the thread location 294 // to detect any duplicate events. 295 296 if (enabled) { 297 // If enabling breakpoint, no need to reset. 298 // Can't do anything if empty stack. 299 if (event_type == JVMTI_EVENT_SINGLE_STEP && _thread->has_last_Java_frame()) { 300 jmethodID method_id; 301 int bci; 302 // The java thread stack may not be walkable for a running thread 303 // so get current location at safepoint. 304 VM_GetCurrentLocation op(_thread); 305 VMThread::execute(&op); 306 op.get_current_location(&method_id, &bci); 307 set_current_location(method_id, bci); 308 } 309 } else if (event_type == JVMTI_EVENT_SINGLE_STEP || !is_enabled(JVMTI_EVENT_SINGLE_STEP)) { 310 // If this is to disable breakpoint, also check if single-step is not enabled 311 clear_current_location(); 312 } 313} 314