jvmtiEnvThreadState.cpp revision 1879:f95d63e2154a
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 */ 24 25#include "precompiled.hpp" 26#include "classfile/systemDictionary.hpp" 27#include "interpreter/interpreter.hpp" 28#include "jvmtifiles/jvmtiEnv.hpp" 29#include "memory/resourceArea.hpp" 30#include "prims/jvmtiEnvThreadState.hpp" 31#include "prims/jvmtiEventController.inline.hpp" 32#include "prims/jvmtiImpl.hpp" 33#include "runtime/handles.hpp" 34#include "runtime/handles.inline.hpp" 35#include "runtime/interfaceSupport.hpp" 36#include "runtime/javaCalls.hpp" 37#include "runtime/signature.hpp" 38#include "runtime/vframe.hpp" 39#include "runtime/vm_operations.hpp" 40 41 42/////////////////////////////////////////////////////////////// 43// 44// class JvmtiFramePop 45// 46 47#ifndef PRODUCT 48void JvmtiFramePop::print() { 49 tty->print_cr("_frame_number=%d", _frame_number); 50} 51#endif 52 53 54/////////////////////////////////////////////////////////////// 55// 56// class JvmtiFramePops - private methods 57// 58 59void 60JvmtiFramePops::set(JvmtiFramePop& fp) { 61 if (_pops->find(fp.frame_number()) < 0) { 62 _pops->append(fp.frame_number()); 63 } 64} 65 66 67void 68JvmtiFramePops::clear(JvmtiFramePop& fp) { 69 assert(_pops->length() > 0, "No more frame pops"); 70 71 _pops->remove(fp.frame_number()); 72} 73 74 75int 76JvmtiFramePops::clear_to(JvmtiFramePop& fp) { 77 int cleared = 0; 78 int index = 0; 79 while (index < _pops->length()) { 80 JvmtiFramePop pop = JvmtiFramePop(_pops->at(index)); 81 if (pop.above_on_stack(fp)) { 82 _pops->remove_at(index); 83 ++cleared; 84 } else { 85 ++index; 86 } 87 } 88 return cleared; 89} 90 91 92/////////////////////////////////////////////////////////////// 93// 94// class JvmtiFramePops - public methods 95// 96 97JvmtiFramePops::JvmtiFramePops() { 98 _pops = new (ResourceObj::C_HEAP) GrowableArray<int> (2, true); 99} 100 101JvmtiFramePops::~JvmtiFramePops() { 102 // return memory to c_heap. 103 delete _pops; 104} 105 106 107#ifndef PRODUCT 108void JvmtiFramePops::print() { 109 ResourceMark rm; 110 111 int n = _pops->length(); 112 for (int i=0; i<n; i++) { 113 JvmtiFramePop fp = JvmtiFramePop(_pops->at(i)); 114 tty->print("%d: ", i); 115 fp.print(); 116 tty->print_cr(""); 117 } 118} 119#endif 120 121/////////////////////////////////////////////////////////////// 122// 123// class JvmtiEnvThreadState 124// 125// Instances of JvmtiEnvThreadState hang off of each JvmtiThreadState, 126// one per JvmtiEnv. 127// 128 129JvmtiEnvThreadState::JvmtiEnvThreadState(JavaThread *thread, JvmtiEnvBase *env) : 130 _event_enable() { 131 _thread = thread; 132 _env = (JvmtiEnv*)env; 133 _next = NULL; 134 _frame_pops = NULL; 135 _current_bci = 0; 136 _current_method_id = NULL; 137 _breakpoint_posted = false; 138 _single_stepping_posted = false; 139 _agent_thread_local_storage_data = NULL; 140} 141 142JvmtiEnvThreadState::~JvmtiEnvThreadState() { 143 delete _frame_pops; 144 _frame_pops = NULL; 145} 146 147// Given that a new (potential) event has come in, 148// maintain the current JVMTI location on a per-thread per-env basis 149// and use it to filter out duplicate events: 150// - instruction rewrites 151// - breakpoint followed by single step 152// - single step at a breakpoint 153void JvmtiEnvThreadState::compare_and_set_current_location(methodOop new_method, 154 address new_location, jvmtiEvent event) { 155 156 int new_bci = new_location - new_method->code_base(); 157 158 // The method is identified and stored as a jmethodID which is safe in this 159 // case because the class cannot be unloaded while a method is executing. 160 jmethodID new_method_id = new_method->jmethod_id(); 161 162 // the last breakpoint or single step was at this same location 163 if (_current_bci == new_bci && _current_method_id == new_method_id) { 164 switch (event) { 165 case JVMTI_EVENT_BREAKPOINT: 166 // Repeat breakpoint is complicated. If we previously posted a breakpoint 167 // event at this location and if we also single stepped at this location 168 // then we skip the duplicate breakpoint. 169 _breakpoint_posted = _breakpoint_posted && _single_stepping_posted; 170 break; 171 case JVMTI_EVENT_SINGLE_STEP: 172 // Repeat single step is easy: just don't post it again. 173 // If step is pending for popframe then it may not be 174 // a repeat step. The new_bci and method_id is same as current_bci 175 // and current method_id after pop and step for recursive calls. 176 // This has been handled by clearing the location 177 _single_stepping_posted = true; 178 break; 179 default: 180 assert(false, "invalid event value passed"); 181 break; 182 } 183 return; 184 } 185 186 set_current_location(new_method_id, new_bci); 187 _breakpoint_posted = false; 188 _single_stepping_posted = false; 189} 190 191 192JvmtiFramePops* JvmtiEnvThreadState::get_frame_pops() { 193#ifdef ASSERT 194 uint32_t debug_bits = 0; 195#endif 196 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 197 "frame pop data only accessible from same thread or while suspended"); 198 199 if (_frame_pops == NULL) { 200 _frame_pops = new JvmtiFramePops(); 201 assert(_frame_pops != NULL, "_frame_pops != NULL"); 202 } 203 return _frame_pops; 204} 205 206 207bool JvmtiEnvThreadState::has_frame_pops() { 208 return _frame_pops == NULL? false : (_frame_pops->length() > 0); 209} 210 211void JvmtiEnvThreadState::set_frame_pop(int frame_number) { 212#ifdef ASSERT 213 uint32_t debug_bits = 0; 214#endif 215 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 216 "frame pop data only accessible from same thread or while suspended"); 217 JvmtiFramePop fpop(frame_number); 218 JvmtiEventController::set_frame_pop(this, fpop); 219} 220 221 222void JvmtiEnvThreadState::clear_frame_pop(int frame_number) { 223#ifdef ASSERT 224 uint32_t debug_bits = 0; 225#endif 226 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 227 "frame pop data only accessible from same thread or while suspended"); 228 JvmtiFramePop fpop(frame_number); 229 JvmtiEventController::clear_frame_pop(this, fpop); 230} 231 232 233void JvmtiEnvThreadState::clear_to_frame_pop(int frame_number) { 234#ifdef ASSERT 235 uint32_t debug_bits = 0; 236#endif 237 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 238 "frame pop data only accessible from same thread or while suspended"); 239 JvmtiFramePop fpop(frame_number); 240 JvmtiEventController::clear_to_frame_pop(this, fpop); 241} 242 243 244bool JvmtiEnvThreadState::is_frame_pop(int cur_frame_number) { 245#ifdef ASSERT 246 uint32_t debug_bits = 0; 247#endif 248 assert(get_thread() == Thread::current() || JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 249 "frame pop data only accessible from same thread or while suspended"); 250 if (!get_thread()->is_interp_only_mode() || _frame_pops == NULL) { 251 return false; 252 } 253 JvmtiFramePop fp(cur_frame_number); 254 return get_frame_pops()->contains(fp); 255} 256 257 258class VM_GetCurrentLocation : public VM_Operation { 259 private: 260 JavaThread *_thread; 261 jmethodID _method_id; 262 int _bci; 263 264 public: 265 VM_GetCurrentLocation(JavaThread *thread) { 266 _thread = thread; 267 } 268 VMOp_Type type() const { return VMOp_GetCurrentLocation; } 269 void doit() { 270 ResourceMark rmark; // _thread != Thread::current() 271 RegisterMap rm(_thread, false); 272 javaVFrame* vf = _thread->last_java_vframe(&rm); 273 assert(vf != NULL, "must have last java frame"); 274 methodOop method = vf->method(); 275 _method_id = method->jmethod_id(); 276 _bci = vf->bci(); 277 } 278 void get_current_location(jmethodID *method_id, int *bci) { 279 *method_id = _method_id; 280 *bci = _bci; 281 } 282}; 283 284void JvmtiEnvThreadState::reset_current_location(jvmtiEvent event_type, bool enabled) { 285 assert(event_type == JVMTI_EVENT_SINGLE_STEP || event_type == JVMTI_EVENT_BREAKPOINT, 286 "must be single-step or breakpoint event"); 287 288 // Current location is used to detect the following: 289 // 1) a breakpoint event followed by single-stepping to the same bci 290 // 2) single-step to a bytecode that will be transformed to a fast version 291 // We skip to avoid posting the duplicate single-stepping event. 292 293 // If single-stepping is disabled, clear current location so that 294 // single-stepping to the same method and bcp at a later time will be 295 // detected if single-stepping is enabled at that time (see 4388912). 296 297 // If single-stepping is enabled, set the current location to the 298 // current method and bcp. This covers the following type of case, 299 // e.g., the debugger stepi command: 300 // - bytecode single stepped 301 // - SINGLE_STEP event posted and SINGLE_STEP event disabled 302 // - SINGLE_STEP event reenabled 303 // - bytecode rewritten to fast version 304 305 // If breakpoint event is disabled, clear current location only if 306 // single-stepping is not enabled. Otherwise, keep the thread location 307 // to detect any duplicate events. 308 309 if (enabled) { 310 // If enabling breakpoint, no need to reset. 311 // Can't do anything if empty stack. 312 if (event_type == JVMTI_EVENT_SINGLE_STEP && _thread->has_last_Java_frame()) { 313 jmethodID method_id; 314 int bci; 315 // The java thread stack may not be walkable for a running thread 316 // so get current location at safepoint. 317 VM_GetCurrentLocation op(_thread); 318 VMThread::execute(&op); 319 op.get_current_location(&method_id, &bci); 320 set_current_location(method_id, bci); 321 } 322 } else if (event_type == JVMTI_EVENT_SINGLE_STEP || !is_enabled(JVMTI_EVENT_SINGLE_STEP)) { 323 // If this is to disable breakpoint, also check if single-step is not enabled 324 clear_current_location(); 325 } 326} 327