jvmtiThreadState.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/_jvmtiThreadState.cpp.incl" 27 28// marker for when the stack depth has been reset and is now unknown. 29// any negative number would work but small ones might obscure an 30// underrun error. 31static const int UNKNOWN_STACK_DEPTH = -99; 32 33/////////////////////////////////////////////////////////////// 34// 35// class JvmtiThreadState 36// 37// Instances of JvmtiThreadState hang off of each thread. 38// Thread local storage for JVMTI. 39// 40 41JvmtiThreadState *JvmtiThreadState::_head = NULL; 42 43JvmtiThreadState::JvmtiThreadState(JavaThread* thread) 44 : _thread_event_enable() { 45 assert(JvmtiThreadState_lock->is_locked(), "sanity check"); 46 _thread = thread; 47 _exception_detected = false; 48 _exception_caught = false; 49 _debuggable = true; 50 _hide_single_stepping = false; 51 _hide_level = 0; 52 _pending_step_for_popframe = false; 53 _class_being_redefined = NULL; 54 _class_load_kind = jvmti_class_load_kind_load; 55 _head_env_thread_state = NULL; 56 _dynamic_code_event_collector = NULL; 57 _vm_object_alloc_event_collector = NULL; 58 _the_class_for_redefinition_verification = NULL; 59 _scratch_class_for_redefinition_verification = NULL; 60 61 // JVMTI ForceEarlyReturn support 62 _pending_step_for_earlyret = false; 63 _earlyret_state = earlyret_inactive; 64 _earlyret_tos = ilgl; 65 _earlyret_value.j = 0L; 66 _earlyret_oop = NULL; 67 68 // add all the JvmtiEnvThreadState to the new JvmtiThreadState 69 { 70 JvmtiEnvIterator it; 71 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 72 if (env->is_valid()) { 73 add_env(env); 74 } 75 } 76 } 77 78 // link us into the list 79 { 80 // The thread state list manipulation code must not have safepoints. 81 // See periodic_clean_up(). 82 debug_only(No_Safepoint_Verifier nosafepoint;) 83 84 _prev = NULL; 85 _next = _head; 86 if (_head != NULL) { 87 _head->_prev = this; 88 } 89 _head = this; 90 } 91 92 // set this as the state for the thread 93 thread->set_jvmti_thread_state(this); 94} 95 96 97JvmtiThreadState::~JvmtiThreadState() { 98 assert(JvmtiThreadState_lock->is_locked(), "sanity check"); 99 100 // clear this as the state for the thread 101 get_thread()->set_jvmti_thread_state(NULL); 102 103 // zap our env thread states 104 { 105 JvmtiEnvBase::entering_dying_thread_env_iteration(); 106 JvmtiEnvThreadStateIterator it(this); 107 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ) { 108 JvmtiEnvThreadState* zap = ets; 109 ets = it.next(ets); 110 delete zap; 111 } 112 JvmtiEnvBase::leaving_dying_thread_env_iteration(); 113 } 114 115 // remove us from the list 116 { 117 // The thread state list manipulation code must not have safepoints. 118 // See periodic_clean_up(). 119 debug_only(No_Safepoint_Verifier nosafepoint;) 120 121 if (_prev == NULL) { 122 assert(_head == this, "sanity check"); 123 _head = _next; 124 } else { 125 assert(_head != this, "sanity check"); 126 _prev->_next = _next; 127 } 128 if (_next != NULL) { 129 _next->_prev = _prev; 130 } 131 _next = NULL; 132 _prev = NULL; 133 } 134} 135 136 137void 138JvmtiThreadState::periodic_clean_up() { 139 assert(SafepointSynchronize::is_at_safepoint(), "at safepoint"); 140 141 // This iteration is initialized with "_head" instead of "JvmtiThreadState::first()" 142 // because the latter requires the JvmtiThreadState_lock. 143 // This iteration is safe at a safepoint as well, see the No_Safepoint_Verifier 144 // asserts at all list manipulation sites. 145 for (JvmtiThreadState *state = _head; state != NULL; state = state->next()) { 146 // For each environment thread state corresponding to an invalid environment 147 // unlink it from the list and deallocate it. 148 JvmtiEnvThreadStateIterator it(state); 149 JvmtiEnvThreadState* previous_ets = NULL; 150 JvmtiEnvThreadState* ets = it.first(); 151 while (ets != NULL) { 152 if (ets->get_env()->is_valid()) { 153 previous_ets = ets; 154 ets = it.next(ets); 155 } else { 156 // This one isn't valid, remove it from the list and deallocate it 157 JvmtiEnvThreadState* defunct_ets = ets; 158 ets = ets->next(); 159 if (previous_ets == NULL) { 160 assert(state->head_env_thread_state() == defunct_ets, "sanity check"); 161 state->set_head_env_thread_state(ets); 162 } else { 163 previous_ets->set_next(ets); 164 } 165 delete defunct_ets; 166 } 167 } 168 } 169} 170 171void JvmtiThreadState::add_env(JvmtiEnvBase *env) { 172 assert(JvmtiThreadState_lock->is_locked(), "sanity check"); 173 174 JvmtiEnvThreadState *new_ets = new JvmtiEnvThreadState(_thread, env); 175 // add this environment thread state to the end of the list (order is important) 176 { 177 // list deallocation (which occurs at a safepoint) cannot occur simultaneously 178 debug_only(No_Safepoint_Verifier nosafepoint;) 179 180 JvmtiEnvThreadStateIterator it(this); 181 JvmtiEnvThreadState* previous_ets = NULL; 182 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) { 183 previous_ets = ets; 184 } 185 if (previous_ets == NULL) { 186 set_head_env_thread_state(new_ets); 187 } else { 188 previous_ets->set_next(new_ets); 189 } 190 } 191} 192 193 194 195 196void JvmtiThreadState::enter_interp_only_mode() { 197 assert(_thread->get_interp_only_mode() == 0, "entering interp only when mode not zero"); 198 _thread->increment_interp_only_mode(); 199} 200 201 202void JvmtiThreadState::leave_interp_only_mode() { 203 assert(_thread->get_interp_only_mode() == 1, "leaving interp only when mode not one"); 204 _thread->decrement_interp_only_mode(); 205} 206 207 208// Helper routine used in several places 209int JvmtiThreadState::count_frames() { 210#ifdef ASSERT 211 uint32_t debug_bits = 0; 212#endif 213 assert(SafepointSynchronize::is_at_safepoint() || 214 JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 215 "at safepoint or must be suspended"); 216 217 if (!get_thread()->has_last_Java_frame()) return 0; // no Java frames 218 219 ResourceMark rm; 220 RegisterMap reg_map(get_thread()); 221 javaVFrame *jvf = get_thread()->last_java_vframe(®_map); 222 int n = 0; 223 // tty->print_cr("CSD: counting frames on %s ...", 224 // JvmtiTrace::safe_get_thread_name(get_thread())); 225 while (jvf != NULL) { 226 methodOop method = jvf->method(); 227 // tty->print_cr("CSD: frame - method %s.%s - loc %d", 228 // method->klass_name()->as_C_string(), 229 // method->name()->as_C_string(), 230 // jvf->bci() ); 231 jvf = jvf->java_sender(); 232 n++; 233 } 234 // tty->print_cr("CSD: frame count: %d", n); 235 return n; 236} 237 238 239void JvmtiThreadState::invalidate_cur_stack_depth() { 240 Thread *cur = Thread::current(); 241 uint32_t debug_bits = 0; 242 243 // The caller can be the VMThread at a safepoint, the current thread 244 // or the target thread must be suspended. 245 guarantee((cur->is_VM_thread() && SafepointSynchronize::is_at_safepoint()) || 246 (JavaThread *)cur == get_thread() || 247 JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 248 "sanity check"); 249 250 _cur_stack_depth = UNKNOWN_STACK_DEPTH; 251} 252 253void JvmtiThreadState::incr_cur_stack_depth() { 254 guarantee(JavaThread::current() == get_thread(), "must be current thread"); 255 256 if (!is_interp_only_mode()) { 257 _cur_stack_depth = UNKNOWN_STACK_DEPTH; 258 } 259 if (_cur_stack_depth != UNKNOWN_STACK_DEPTH) { 260 ++_cur_stack_depth; 261 } 262} 263 264void JvmtiThreadState::decr_cur_stack_depth() { 265 guarantee(JavaThread::current() == get_thread(), "must be current thread"); 266 267 if (!is_interp_only_mode()) { 268 _cur_stack_depth = UNKNOWN_STACK_DEPTH; 269 } 270 if (_cur_stack_depth != UNKNOWN_STACK_DEPTH) { 271 --_cur_stack_depth; 272 assert(_cur_stack_depth >= 0, "incr/decr_cur_stack_depth mismatch"); 273 } 274} 275 276int JvmtiThreadState::cur_stack_depth() { 277 uint32_t debug_bits = 0; 278 guarantee(JavaThread::current() == get_thread() || 279 JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits), 280 "must be current thread or suspended"); 281 282 if (!is_interp_only_mode() || _cur_stack_depth == UNKNOWN_STACK_DEPTH) { 283 _cur_stack_depth = count_frames(); 284 } else { 285 // heavy weight assert 286 assert(_cur_stack_depth == count_frames(), 287 "cur_stack_depth out of sync"); 288 } 289 return _cur_stack_depth; 290} 291 292bool JvmtiThreadState::may_be_walked() { 293 return (get_thread()->is_being_ext_suspended() || (JavaThread::current() == get_thread())); 294} 295 296 297void JvmtiThreadState::process_pending_step_for_popframe() { 298 // We are single stepping as the last part of the PopFrame() dance 299 // so we have some house keeping to do. 300 301 JavaThread *thr = get_thread(); 302 if (thr->popframe_condition() != JavaThread::popframe_inactive) { 303 // If the popframe_condition field is not popframe_inactive, then 304 // we missed all of the popframe_field cleanup points: 305 // 306 // - unpack_frames() was not called (nothing to deopt) 307 // - remove_activation_preserving_args_entry() was not called 308 // (did not get suspended in a call_vm() family call and did 309 // not complete a call_vm() family call on the way here) 310 thr->clear_popframe_condition(); 311 } 312 313 // clearing the flag indicates we are done with the PopFrame() dance 314 clr_pending_step_for_popframe(); 315 316 // If step is pending for popframe then it may not be 317 // a repeat step. The new_bci and method_id is same as current_bci 318 // and current method_id after pop and step for recursive calls. 319 // Force the step by clearing the last location. 320 JvmtiEnvThreadStateIterator it(this); 321 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) { 322 ets->clear_current_location(); 323 } 324} 325 326 327// Class: JvmtiThreadState 328// Function: update_for_pop_top_frame 329// Description: 330// This function removes any frame pop notification request for 331// the top frame and invalidates both the current stack depth and 332// all cached frameIDs. 333// 334// Called by: PopFrame 335// 336void JvmtiThreadState::update_for_pop_top_frame() { 337 if (is_interp_only_mode()) { 338 // remove any frame pop notification request for the top frame 339 // in any environment 340 int popframe_number = cur_stack_depth(); 341 { 342 JvmtiEnvThreadStateIterator it(this); 343 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) { 344 if (ets->is_frame_pop(popframe_number)) { 345 ets->clear_frame_pop(popframe_number); 346 } 347 } 348 } 349 // force stack depth to be recalculated 350 invalidate_cur_stack_depth(); 351 } else { 352 assert(!is_enabled(JVMTI_EVENT_FRAME_POP), "Must have no framepops set"); 353 } 354} 355 356 357void JvmtiThreadState::process_pending_step_for_earlyret() { 358 // We are single stepping as the last part of the ForceEarlyReturn 359 // dance so we have some house keeping to do. 360 361 if (is_earlyret_pending()) { 362 // If the earlyret_state field is not earlyret_inactive, then 363 // we missed all of the earlyret_field cleanup points: 364 // 365 // - remove_activation() was not called 366 // (did not get suspended in a call_vm() family call and did 367 // not complete a call_vm() family call on the way here) 368 // 369 // One legitimate way for us to miss all the cleanup points is 370 // if we got here right after handling a compiled return. If that 371 // is the case, then we consider our return from compiled code to 372 // complete the ForceEarlyReturn request and we clear the condition. 373 clr_earlyret_pending(); 374 set_earlyret_oop(NULL); 375 clr_earlyret_value(); 376 } 377 378 // clearing the flag indicates we are done with 379 // the ForceEarlyReturn() dance 380 clr_pending_step_for_earlyret(); 381 382 // If step is pending for earlyret then it may not be a repeat step. 383 // The new_bci and method_id is same as current_bci and current 384 // method_id after earlyret and step for recursive calls. 385 // Force the step by clearing the last location. 386 JvmtiEnvThreadStateIterator it(this); 387 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) { 388 ets->clear_current_location(); 389 } 390} 391 392void JvmtiThreadState::oops_do(OopClosure* f) { 393 f->do_oop((oop*) &_earlyret_oop); 394} 395