1 /* 2 * Copyright (c) 1997, 2018, 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 #ifndef SHARE_VM_RUNTIME_INTERFACESUPPORT_INLINE_HPP 26 #define SHARE_VM_RUNTIME_INTERFACESUPPORT_INLINE_HPP 27 28 #include "runtime/handles.inline.hpp" 29 #include "runtime/mutexLocker.hpp" 30 #include "runtime/orderAccess.hpp" 31 #include "runtime/os.hpp" 32 #include "runtime/safepointMechanism.inline.hpp" 33 #include "runtime/safepointVerifiers.hpp" 34 #include "runtime/thread.hpp" 35 #include "runtime/vm_operations.hpp" 36 #include "utilities/globalDefinitions.hpp" 37 #include "utilities/macros.hpp" 38 #include "utilities/preserveException.hpp" 39 40 // Wrapper for all entry points to the virtual machine. 41 42 // InterfaceSupport provides functionality used by the VM_LEAF_BASE and 43 // VM_ENTRY_BASE macros. These macros are used to guard entry points into 44 // the VM and perform checks upon leave of the VM. 45 46 47 class InterfaceSupport: AllStatic { 48 # ifdef ASSERT 49 public: 50 static long _scavenge_alot_counter; 51 static long _fullgc_alot_counter; 52 static long _number_of_calls; 53 static long _fullgc_alot_invocation; 54 55 // Helper methods used to implement +ScavengeALot and +FullGCALot 56 static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); } 57 static void gc_alot(); 58 59 static void walk_stack_from(vframe* start_vf); 60 static void walk_stack(); 61 62 static void zombieAll(); 63 static void deoptimizeAll(); 64 static void stress_derived_pointers(); 65 static void verify_stack(); 66 static void verify_last_frame(); 67 # endif 68 69 public: 70 static void serialize_thread_state_with_handler(JavaThread* thread) { 71 serialize_thread_state_internal(thread, true); 72 } 73 74 // Should only call this if we know that we have a proper SEH set up. 75 static void serialize_thread_state(JavaThread* thread) { 76 serialize_thread_state_internal(thread, false); 77 } 78 79 private: 80 static void serialize_thread_state_internal(JavaThread* thread, bool needs_exception_handler) { 81 // Make sure new state is seen by VM thread 82 OrderAccess::fence(); 83 } 84 }; 85 86 87 // Basic class for all thread transition classes. 88 89 class ThreadStateTransition : public StackObj { 90 protected: 91 JavaThread* _thread; 92 public: 93 ThreadStateTransition(JavaThread *thread) { 94 _thread = thread; 95 assert(thread != NULL && thread->is_Java_thread(), "must be Java thread"); 96 } 97 98 // Change threadstate in a manner, so safepoint can detect changes. 99 // Time-critical: called on exit from every runtime routine 100 static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) { 101 assert(from != _thread_in_Java, "use transition_from_java"); 102 assert(from != _thread_in_native, "use transition_from_native"); 103 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states"); 104 assert(thread->thread_state() == from, "coming from wrong thread state"); 105 // Change to transition state 106 thread->set_thread_state((JavaThreadState)(from + 1)); 107 108 InterfaceSupport::serialize_thread_state(thread); 109 110 SafepointMechanism::block_if_requested(thread); 111 thread->set_thread_state(to); 112 113 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();) 114 } 115 116 // transition_and_fence must be used on any thread state transition 117 // where there might not be a Java call stub on the stack, in 118 // particular on Windows where the Structured Exception Handler is 119 // set up in the call stub. 120 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) { 121 assert(thread->thread_state() == from, "coming from wrong thread state"); 122 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states"); 123 // Change to transition state 124 thread->set_thread_state((JavaThreadState)(from + 1)); 125 126 InterfaceSupport::serialize_thread_state_with_handler(thread); 127 128 SafepointMechanism::block_if_requested(thread); 129 thread->set_thread_state(to); 130 131 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();) 132 } 133 134 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we 135 // never block on entry to the VM. This will break the code, since e.g. preserve arguments 136 // have not been setup. 137 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) { 138 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state"); 139 thread->set_thread_state(to); 140 } 141 142 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) { 143 assert((to & 1) == 0, "odd numbers are transitions states"); 144 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state"); 145 // Change to transition state 146 thread->set_thread_state(_thread_in_native_trans); 147 148 InterfaceSupport::serialize_thread_state_with_handler(thread); 149 150 // We never install asynchronous exceptions when coming (back) in 151 // to the runtime from native code because the runtime is not set 152 // up to handle exceptions floating around at arbitrary points. 153 if (SafepointMechanism::should_block(thread) || thread->is_suspend_after_native()) { 154 JavaThread::check_safepoint_and_suspend_for_native_trans(thread); 155 156 // Clear unhandled oops anywhere where we could block, even if we don't. 157 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();) 158 } 159 160 thread->set_thread_state(to); 161 } 162 protected: 163 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); } 164 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); } 165 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); } 166 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); } 167 }; 168 169 class ThreadInVMForHandshake : public ThreadStateTransition { 170 const JavaThreadState _original_state; 171 172 void transition_back() { 173 // This can be invoked from transition states and must return to the original state properly 174 assert(_thread->thread_state() == _thread_in_vm, "should only call when leaving VM after handshake"); 175 _thread->set_thread_state(_thread_in_vm_trans); 176 177 InterfaceSupport::serialize_thread_state(_thread); 178 179 SafepointMechanism::block_if_requested(_thread); 180 181 _thread->set_thread_state(_original_state); 182 } 183 184 public: 185 186 ThreadInVMForHandshake(JavaThread* thread) : ThreadStateTransition(thread), 187 _original_state(thread->thread_state()) { 188 189 if (thread->has_last_Java_frame()) { 190 thread->frame_anchor()->make_walkable(thread); 191 } 192 193 thread->set_thread_state(_thread_in_vm); 194 } 195 196 ~ThreadInVMForHandshake() { 197 transition_back(); 198 } 199 200 }; 201 202 class ThreadInVMfromJava : public ThreadStateTransition { 203 public: 204 ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) { 205 trans_from_java(_thread_in_vm); 206 } 207 ~ThreadInVMfromJava() { 208 if (_thread->stack_yellow_reserved_zone_disabled()) { 209 _thread->enable_stack_yellow_reserved_zone(); 210 } 211 trans(_thread_in_vm, _thread_in_Java); 212 // Check for pending. async. exceptions or suspends. 213 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(); 214 } 215 }; 216 217 218 class ThreadInVMfromUnknown { 219 private: 220 JavaThread* _thread; 221 public: 222 ThreadInVMfromUnknown() : _thread(NULL) { 223 Thread* t = Thread::current(); 224 if (t->is_Java_thread()) { 225 JavaThread* t2 = (JavaThread*) t; 226 if (t2->thread_state() == _thread_in_native) { 227 _thread = t2; 228 ThreadStateTransition::transition_from_native(t2, _thread_in_vm); 229 // Used to have a HandleMarkCleaner but that is dangerous as 230 // it could free a handle in our (indirect, nested) caller. 231 // We expect any handles will be short lived and figure we 232 // don't need an actual HandleMark. 233 } 234 } 235 } 236 ~ThreadInVMfromUnknown() { 237 if (_thread) { 238 ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native); 239 } 240 } 241 }; 242 243 244 class ThreadInVMfromNative : public ThreadStateTransition { 245 public: 246 ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) { 247 trans_from_native(_thread_in_vm); 248 } 249 ~ThreadInVMfromNative() { 250 trans_and_fence(_thread_in_vm, _thread_in_native); 251 } 252 }; 253 254 255 class ThreadToNativeFromVM : public ThreadStateTransition { 256 public: 257 ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) { 258 // We are leaving the VM at this point and going directly to native code. 259 // Block, if we are in the middle of a safepoint synchronization. 260 assert(!thread->owns_locks(), "must release all locks when leaving VM"); 261 thread->frame_anchor()->make_walkable(thread); 262 trans_and_fence(_thread_in_vm, _thread_in_native); 263 // Check for pending. async. exceptions or suspends. 264 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false); 265 } 266 267 ~ThreadToNativeFromVM() { 268 trans_from_native(_thread_in_vm); 269 assert(!_thread->is_pending_jni_exception_check(), "Pending JNI Exception Check"); 270 // We don't need to clear_walkable because it will happen automagically when we return to java 271 } 272 }; 273 274 275 class ThreadBlockInVM : public ThreadStateTransition { 276 public: 277 ThreadBlockInVM(JavaThread *thread) 278 : ThreadStateTransition(thread) { 279 // Once we are blocked vm expects stack to be walkable 280 thread->frame_anchor()->make_walkable(thread); 281 trans_and_fence(_thread_in_vm, _thread_blocked); 282 } 283 ~ThreadBlockInVM() { 284 trans_and_fence(_thread_blocked, _thread_in_vm); 285 // We don't need to clear_walkable because it will happen automagically when we return to java 286 } 287 }; 288 289 290 // This special transition class is only used to prevent asynchronous exceptions 291 // from being installed on vm exit in situations where we can't tolerate them. 292 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705. 293 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition { 294 public: 295 ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) { 296 trans_from_java(_thread_in_vm); 297 } 298 ~ThreadInVMfromJavaNoAsyncException() { 299 if (_thread->stack_yellow_reserved_zone_disabled()) { 300 _thread->enable_stack_yellow_reserved_zone(); 301 } 302 trans(_thread_in_vm, _thread_in_Java); 303 // NOTE: We do not check for pending. async. exceptions. 304 // If we did and moved the pending async exception over into the 305 // pending exception field, we would need to deopt (currently C2 306 // only). However, to do so would require that we transition back 307 // to the _thread_in_vm state. Instead we postpone the handling of 308 // the async exception. 309 310 311 // Check for pending. suspends only. 312 if (_thread->has_special_runtime_exit_condition()) 313 _thread->handle_special_runtime_exit_condition(false); 314 } 315 }; 316 317 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro. 318 // Can be used to verify properties on enter/exit of the VM. 319 320 #ifdef ASSERT 321 class VMEntryWrapper { 322 public: 323 VMEntryWrapper(); 324 ~VMEntryWrapper(); 325 }; 326 327 328 class VMNativeEntryWrapper { 329 public: 330 VMNativeEntryWrapper() { 331 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot(); 332 } 333 334 ~VMNativeEntryWrapper() { 335 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot(); 336 } 337 }; 338 339 #endif 340 341 342 // VM-internal runtime interface support 343 344 // Definitions for JRT (Java (Compiler/Shared) Runtime) 345 346 // JRT_LEAF currently can be called from either _thread_in_Java or 347 // _thread_in_native mode. In _thread_in_native, it is ok 348 // for another thread to trigger GC. The rest of the JRT_LEAF 349 // rules apply. 350 class JRTLeafVerifier : public NoSafepointVerifier { 351 static bool should_verify_GC(); 352 public: 353 #ifdef ASSERT 354 JRTLeafVerifier(); 355 ~JRTLeafVerifier(); 356 #else 357 JRTLeafVerifier() {} 358 ~JRTLeafVerifier() {} 359 #endif 360 }; 361 362 #ifdef ASSERT 363 364 class RuntimeHistogramElement : public HistogramElement { 365 public: 366 RuntimeHistogramElement(const char* name); 367 }; 368 369 #define TRACE_CALL(result_type, header) \ 370 InterfaceSupport::_number_of_calls++; \ 371 if (CountRuntimeCalls) { \ 372 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \ 373 if (e != NULL) e->increment_count(); \ 374 } 375 #else 376 #define TRACE_CALL(result_type, header) \ 377 /* do nothing */ 378 #endif 379 380 381 // LEAF routines do not lock, GC or throw exceptions 382 383 #define VM_LEAF_BASE(result_type, header) \ 384 TRACE_CALL(result_type, header) \ 385 debug_only(NoHandleMark __hm;) \ 386 os::verify_stack_alignment(); \ 387 /* begin of body */ 388 389 #define VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) \ 390 TRACE_CALL(result_type, header) \ 391 debug_only(ResetNoHandleMark __rnhm;) \ 392 HandleMarkCleaner __hm(thread); \ 393 Thread* THREAD = thread; \ 394 os::verify_stack_alignment(); \ 395 /* begin of body */ 396 397 398 // ENTRY routines may lock, GC and throw exceptions 399 400 #define VM_ENTRY_BASE(result_type, header, thread) \ 401 TRACE_CALL(result_type, header) \ 402 HandleMarkCleaner __hm(thread); \ 403 Thread* THREAD = thread; \ 404 os::verify_stack_alignment(); \ 405 /* begin of body */ 406 407 408 // QUICK_ENTRY routines behave like ENTRY but without a handle mark 409 410 #define VM_QUICK_ENTRY_BASE(result_type, header, thread) \ 411 TRACE_CALL(result_type, header) \ 412 debug_only(NoHandleMark __hm;) \ 413 Thread* THREAD = thread; \ 414 os::verify_stack_alignment(); \ 415 /* begin of body */ 416 417 418 // Definitions for IRT (Interpreter Runtime) 419 // (thread is an argument passed in to all these routines) 420 421 #define IRT_ENTRY(result_type, header) \ 422 result_type header { \ 423 ThreadInVMfromJava __tiv(thread); \ 424 VM_ENTRY_BASE(result_type, header, thread) \ 425 debug_only(VMEntryWrapper __vew;) 426 427 428 #define IRT_LEAF(result_type, header) \ 429 result_type header { \ 430 VM_LEAF_BASE(result_type, header) \ 431 debug_only(NoSafepointVerifier __nspv(true);) 432 433 434 #define IRT_ENTRY_NO_ASYNC(result_type, header) \ 435 result_type header { \ 436 ThreadInVMfromJavaNoAsyncException __tiv(thread); \ 437 VM_ENTRY_BASE(result_type, header, thread) \ 438 debug_only(VMEntryWrapper __vew;) 439 440 #define IRT_END } 441 442 #define JRT_ENTRY(result_type, header) \ 443 result_type header { \ 444 ThreadInVMfromJava __tiv(thread); \ 445 VM_ENTRY_BASE(result_type, header, thread) \ 446 debug_only(VMEntryWrapper __vew;) 447 448 449 #define JRT_LEAF(result_type, header) \ 450 result_type header { \ 451 VM_LEAF_BASE(result_type, header) \ 452 debug_only(JRTLeafVerifier __jlv;) 453 454 455 #define JRT_ENTRY_NO_ASYNC(result_type, header) \ 456 result_type header { \ 457 ThreadInVMfromJavaNoAsyncException __tiv(thread); \ 458 VM_ENTRY_BASE(result_type, header, thread) \ 459 debug_only(VMEntryWrapper __vew;) 460 461 // Same as JRT Entry but allows for return value after the safepoint 462 // to get back into Java from the VM 463 #define JRT_BLOCK_ENTRY(result_type, header) \ 464 result_type header { \ 465 TRACE_CALL(result_type, header) \ 466 HandleMarkCleaner __hm(thread); 467 468 #define JRT_BLOCK \ 469 { \ 470 ThreadInVMfromJava __tiv(thread); \ 471 Thread* THREAD = thread; \ 472 debug_only(VMEntryWrapper __vew;) 473 474 #define JRT_BLOCK_NO_ASYNC \ 475 { \ 476 ThreadInVMfromJavaNoAsyncException __tiv(thread); \ 477 Thread* THREAD = thread; \ 478 debug_only(VMEntryWrapper __vew;) 479 480 #define JRT_BLOCK_END } 481 482 #define JRT_END } 483 484 // Definitions for JNI 485 486 #define JNI_ENTRY(result_type, header) \ 487 JNI_ENTRY_NO_PRESERVE(result_type, header) \ 488 WeakPreserveExceptionMark __wem(thread); 489 490 #define JNI_ENTRY_NO_PRESERVE(result_type, header) \ 491 extern "C" { \ 492 result_type JNICALL header { \ 493 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 494 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \ 495 ThreadInVMfromNative __tiv(thread); \ 496 debug_only(VMNativeEntryWrapper __vew;) \ 497 VM_ENTRY_BASE(result_type, header, thread) 498 499 500 // Ensure that the VMNativeEntryWrapper constructor, which can cause 501 // a GC, is called outside the NoHandleMark (set via VM_QUICK_ENTRY_BASE). 502 #define JNI_QUICK_ENTRY(result_type, header) \ 503 extern "C" { \ 504 result_type JNICALL header { \ 505 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 506 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \ 507 ThreadInVMfromNative __tiv(thread); \ 508 debug_only(VMNativeEntryWrapper __vew;) \ 509 VM_QUICK_ENTRY_BASE(result_type, header, thread) 510 511 512 #define JNI_LEAF(result_type, header) \ 513 extern "C" { \ 514 result_type JNICALL header { \ 515 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 516 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \ 517 VM_LEAF_BASE(result_type, header) 518 519 520 // Close the routine and the extern "C" 521 #define JNI_END } } 522 523 524 525 // Definitions for JVM 526 527 #define JVM_ENTRY(result_type, header) \ 528 extern "C" { \ 529 result_type JNICALL header { \ 530 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 531 ThreadInVMfromNative __tiv(thread); \ 532 debug_only(VMNativeEntryWrapper __vew;) \ 533 VM_ENTRY_BASE(result_type, header, thread) 534 535 536 #define JVM_ENTRY_NO_ENV(result_type, header) \ 537 extern "C" { \ 538 result_type JNICALL header { \ 539 JavaThread* thread = JavaThread::current(); \ 540 ThreadInVMfromNative __tiv(thread); \ 541 debug_only(VMNativeEntryWrapper __vew;) \ 542 VM_ENTRY_BASE(result_type, header, thread) 543 544 545 #define JVM_QUICK_ENTRY(result_type, header) \ 546 extern "C" { \ 547 result_type JNICALL header { \ 548 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 549 ThreadInVMfromNative __tiv(thread); \ 550 debug_only(VMNativeEntryWrapper __vew;) \ 551 VM_QUICK_ENTRY_BASE(result_type, header, thread) 552 553 554 #define JVM_LEAF(result_type, header) \ 555 extern "C" { \ 556 result_type JNICALL header { \ 557 VM_Exit::block_if_vm_exited(); \ 558 VM_LEAF_BASE(result_type, header) 559 560 561 #define JVM_ENTRY_FROM_LEAF(env, result_type, header) \ 562 { { \ 563 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 564 ThreadInVMfromNative __tiv(thread); \ 565 debug_only(VMNativeEntryWrapper __vew;) \ 566 VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) 567 568 569 #define JVM_END } } 570 571 #endif // SHARE_VM_RUNTIME_INTERFACESUPPORT_INLINE_HPP