1 /* 2 * Copyright (c) 1997, 2017, 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_HPP 26 #define SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP 27 28 #include "gc/shared/gcLocker.hpp" 29 #include "runtime/handles.inline.hpp" 30 #include "runtime/mutexLocker.hpp" 31 #include "runtime/orderAccess.hpp" 32 #include "runtime/os.hpp" 33 #include "runtime/safepointMechanism.inline.hpp" 34 #include "runtime/thread.hpp" 35 #include "utilities/globalDefinitions.hpp" 36 #include "utilities/macros.hpp" 37 #include "utilities/preserveException.hpp" 38 39 // Wrapper for all entry points to the virtual machine. 40 41 // InterfaceSupport provides functionality used by the VM_LEAF_BASE and 42 // VM_ENTRY_BASE macros. These macros are used to guard entry points into 43 // the VM and perform checks upon leave of the VM. 44 45 46 class InterfaceSupport: AllStatic { 47 # ifdef ASSERT 48 public: 49 static long _scavenge_alot_counter; 50 static long _fullgc_alot_counter; 51 static long _number_of_calls; 52 static long _fullgc_alot_invocation; 53 54 // Helper methods used to implement +ScavengeALot and +FullGCALot 55 static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); } 56 static void gc_alot(); 57 58 static void walk_stack_from(vframe* start_vf); 59 static void walk_stack(); 60 61 static void zombieAll(); 62 static void unlinkSymbols(); 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 if (os::is_MP()) { 83 if (UseMembar) { 84 // Force a fence between the write above and read below 85 OrderAccess::fence(); 86 } else { 87 // store to serialize page so VM thread can do pseudo remote membar 88 if (needs_exception_handler) { 89 os::write_memory_serialize_page_with_handler(thread); 90 } else { 91 os::write_memory_serialize_page(thread); 92 } 93 } 94 } 95 } 96 }; 97 98 99 // Basic class for all thread transition classes. 100 101 class ThreadStateTransition : public StackObj { 102 protected: 103 JavaThread* _thread; 104 public: 105 ThreadStateTransition(JavaThread *thread) { 106 _thread = thread; 107 assert(thread != NULL && thread->is_Java_thread(), "must be Java thread"); 108 } 109 110 // Change threadstate in a manner, so safepoint can detect changes. 111 // Time-critical: called on exit from every runtime routine 112 static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) { 113 assert(from != _thread_in_Java, "use transition_from_java"); 114 assert(from != _thread_in_native, "use transition_from_native"); 115 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states"); 116 assert(thread->thread_state() == from, "coming from wrong thread state"); 117 // Change to transition state 118 thread->set_thread_state((JavaThreadState)(from + 1)); 119 120 InterfaceSupport::serialize_thread_state(thread); 121 122 SafepointMechanism::block_if_requested(thread); 123 thread->set_thread_state(to); 124 125 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();) 126 } 127 128 // transition_and_fence must be used on any thread state transition 129 // where there might not be a Java call stub on the stack, in 130 // particular on Windows where the Structured Exception Handler is 131 // set up in the call stub. os::write_memory_serialize_page() can 132 // fault and we can't recover from it on Windows without a SEH in 133 // place. 134 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) { 135 assert(thread->thread_state() == from, "coming from wrong thread state"); 136 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states"); 137 // Change to transition state 138 thread->set_thread_state((JavaThreadState)(from + 1)); 139 140 InterfaceSupport::serialize_thread_state_with_handler(thread); 141 142 SafepointMechanism::block_if_requested(thread); 143 thread->set_thread_state(to); 144 145 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();) 146 } 147 148 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we 149 // never block on entry to the VM. This will break the code, since e.g. preserve arguments 150 // have not been setup. 151 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) { 152 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state"); 153 thread->set_thread_state(to); 154 } 155 156 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) { 157 assert((to & 1) == 0, "odd numbers are transitions states"); 158 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state"); 159 // Change to transition state 160 thread->set_thread_state(_thread_in_native_trans); 161 162 InterfaceSupport::serialize_thread_state_with_handler(thread); 163 164 // We never install asynchronous exceptions when coming (back) in 165 // to the runtime from native code because the runtime is not set 166 // up to handle exceptions floating around at arbitrary points. 167 if (SafepointMechanism::poll(thread) || thread->is_suspend_after_native()) { 168 JavaThread::check_safepoint_and_suspend_for_native_trans(thread); 169 170 // Clear unhandled oops anywhere where we could block, even if we don't. 171 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();) 172 } 173 174 thread->set_thread_state(to); 175 } 176 protected: 177 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); } 178 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); } 179 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); } 180 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); } 181 }; 182 183 class ThreadInVMForHandshake : public ThreadStateTransition { 184 const JavaThreadState _original_state; 185 186 void transition_back() { 187 // This can be invoked from transition states and must return to the original state properly 188 assert(_thread->thread_state() == _thread_in_vm, "should only call when leaving VM after handshake"); 189 _thread->set_thread_state(_thread_in_vm_trans); 190 191 InterfaceSupport::serialize_thread_state(_thread); 192 193 SafepointMechanism::block_if_requested(_thread); 194 195 _thread->set_thread_state(_original_state); 196 } 197 198 public: 199 200 ThreadInVMForHandshake(JavaThread* thread) : ThreadStateTransition(thread), 201 _original_state(thread->thread_state()) { 202 203 if (thread->has_last_Java_frame()) { 204 thread->frame_anchor()->make_walkable(thread); 205 } 206 207 thread->set_thread_state(_thread_in_vm); 208 } 209 210 ~ThreadInVMForHandshake() { 211 transition_back(); 212 } 213 214 }; 215 216 class ThreadInVMfromJava : public ThreadStateTransition { 217 public: 218 ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) { 219 trans_from_java(_thread_in_vm); 220 } 221 ~ThreadInVMfromJava() { 222 if (_thread->stack_yellow_reserved_zone_disabled()) { 223 _thread->enable_stack_yellow_reserved_zone(); 224 } 225 trans(_thread_in_vm, _thread_in_Java); 226 // Check for pending. async. exceptions or suspends. 227 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(); 228 } 229 }; 230 231 232 class ThreadInVMfromUnknown { 233 private: 234 JavaThread* _thread; 235 public: 236 ThreadInVMfromUnknown() : _thread(NULL) { 237 Thread* t = Thread::current(); 238 if (t->is_Java_thread()) { 239 JavaThread* t2 = (JavaThread*) t; 240 if (t2->thread_state() == _thread_in_native) { 241 _thread = t2; 242 ThreadStateTransition::transition_from_native(t2, _thread_in_vm); 243 // Used to have a HandleMarkCleaner but that is dangerous as 244 // it could free a handle in our (indirect, nested) caller. 245 // We expect any handles will be short lived and figure we 246 // don't need an actual HandleMark. 247 } 248 } 249 } 250 ~ThreadInVMfromUnknown() { 251 if (_thread) { 252 ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native); 253 } 254 } 255 }; 256 257 258 class ThreadInVMfromNative : public ThreadStateTransition { 259 public: 260 ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) { 261 trans_from_native(_thread_in_vm); 262 } 263 ~ThreadInVMfromNative() { 264 trans_and_fence(_thread_in_vm, _thread_in_native); 265 } 266 }; 267 268 269 class ThreadToNativeFromVM : public ThreadStateTransition { 270 public: 271 ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) { 272 // We are leaving the VM at this point and going directly to native code. 273 // Block, if we are in the middle of a safepoint synchronization. 274 assert(!thread->owns_locks(), "must release all locks when leaving VM"); 275 thread->frame_anchor()->make_walkable(thread); 276 trans_and_fence(_thread_in_vm, _thread_in_native); 277 // Check for pending. async. exceptions or suspends. 278 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false); 279 } 280 281 ~ThreadToNativeFromVM() { 282 trans_from_native(_thread_in_vm); 283 assert(!_thread->is_pending_jni_exception_check(), "Pending JNI Exception Check"); 284 // We don't need to clear_walkable because it will happen automagically when we return to java 285 } 286 }; 287 288 289 class ThreadBlockInVM : public ThreadStateTransition { 290 public: 291 ThreadBlockInVM(JavaThread *thread) 292 : ThreadStateTransition(thread) { 293 // Once we are blocked vm expects stack to be walkable 294 thread->frame_anchor()->make_walkable(thread); 295 trans_and_fence(_thread_in_vm, _thread_blocked); 296 } 297 ~ThreadBlockInVM() { 298 trans_and_fence(_thread_blocked, _thread_in_vm); 299 // We don't need to clear_walkable because it will happen automagically when we return to java 300 } 301 }; 302 303 304 // This special transition class is only used to prevent asynchronous exceptions 305 // from being installed on vm exit in situations where we can't tolerate them. 306 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705. 307 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition { 308 public: 309 ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) { 310 trans_from_java(_thread_in_vm); 311 } 312 ~ThreadInVMfromJavaNoAsyncException() { 313 if (_thread->stack_yellow_reserved_zone_disabled()) { 314 _thread->enable_stack_yellow_reserved_zone(); 315 } 316 trans(_thread_in_vm, _thread_in_Java); 317 // NOTE: We do not check for pending. async. exceptions. 318 // If we did and moved the pending async exception over into the 319 // pending exception field, we would need to deopt (currently C2 320 // only). However, to do so would require that we transition back 321 // to the _thread_in_vm state. Instead we postpone the handling of 322 // the async exception. 323 324 325 // Check for pending. suspends only. 326 if (_thread->has_special_runtime_exit_condition()) 327 _thread->handle_special_runtime_exit_condition(false); 328 } 329 }; 330 331 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro. 332 // Can be used to verify properties on enter/exit of the VM. 333 334 #ifdef ASSERT 335 class VMEntryWrapper { 336 public: 337 VMEntryWrapper(); 338 ~VMEntryWrapper(); 339 }; 340 341 342 class VMNativeEntryWrapper { 343 public: 344 VMNativeEntryWrapper() { 345 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot(); 346 } 347 348 ~VMNativeEntryWrapper() { 349 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot(); 350 } 351 }; 352 353 #endif 354 355 356 // VM-internal runtime interface support 357 358 #ifdef ASSERT 359 360 class RuntimeHistogramElement : public HistogramElement { 361 public: 362 RuntimeHistogramElement(const char* name); 363 }; 364 365 #define TRACE_CALL(result_type, header) \ 366 InterfaceSupport::_number_of_calls++; \ 367 if (CountRuntimeCalls) { \ 368 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \ 369 if (e != NULL) e->increment_count(); \ 370 } 371 #else 372 #define TRACE_CALL(result_type, header) \ 373 /* do nothing */ 374 #endif 375 376 377 // LEAF routines do not lock, GC or throw exceptions 378 379 #define VM_LEAF_BASE(result_type, header) \ 380 TRACE_CALL(result_type, header) \ 381 debug_only(NoHandleMark __hm;) \ 382 os::verify_stack_alignment(); \ 383 /* begin of body */ 384 385 #define VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) \ 386 TRACE_CALL(result_type, header) \ 387 debug_only(ResetNoHandleMark __rnhm;) \ 388 HandleMarkCleaner __hm(thread); \ 389 Thread* THREAD = thread; \ 390 os::verify_stack_alignment(); \ 391 /* begin of body */ 392 393 394 // ENTRY routines may lock, GC and throw exceptions 395 396 #define VM_ENTRY_BASE(result_type, header, thread) \ 397 TRACE_CALL(result_type, header) \ 398 HandleMarkCleaner __hm(thread); \ 399 Thread* THREAD = thread; \ 400 os::verify_stack_alignment(); \ 401 /* begin of body */ 402 403 404 // QUICK_ENTRY routines behave like ENTRY but without a handle mark 405 406 #define VM_QUICK_ENTRY_BASE(result_type, header, thread) \ 407 TRACE_CALL(result_type, header) \ 408 debug_only(NoHandleMark __hm;) \ 409 Thread* THREAD = thread; \ 410 os::verify_stack_alignment(); \ 411 /* begin of body */ 412 413 414 // Definitions for IRT (Interpreter Runtime) 415 // (thread is an argument passed in to all these routines) 416 417 #define IRT_ENTRY(result_type, header) \ 418 result_type header { \ 419 ThreadInVMfromJava __tiv(thread); \ 420 VM_ENTRY_BASE(result_type, header, thread) \ 421 debug_only(VMEntryWrapper __vew;) 422 423 424 #define IRT_LEAF(result_type, header) \ 425 result_type header { \ 426 VM_LEAF_BASE(result_type, header) \ 427 debug_only(NoSafepointVerifier __nspv(true);) 428 429 430 #define IRT_ENTRY_NO_ASYNC(result_type, header) \ 431 result_type header { \ 432 ThreadInVMfromJavaNoAsyncException __tiv(thread); \ 433 VM_ENTRY_BASE(result_type, header, thread) \ 434 debug_only(VMEntryWrapper __vew;) 435 436 #define IRT_END } 437 438 439 // Definitions for JRT (Java (Compiler/Shared) Runtime) 440 441 #define JRT_ENTRY(result_type, header) \ 442 result_type header { \ 443 ThreadInVMfromJava __tiv(thread); \ 444 VM_ENTRY_BASE(result_type, header, thread) \ 445 debug_only(VMEntryWrapper __vew;) 446 447 448 #define JRT_LEAF(result_type, header) \ 449 result_type header { \ 450 VM_LEAF_BASE(result_type, header) \ 451 debug_only(JRTLeafVerifier __jlv;) 452 453 454 #define JRT_ENTRY_NO_ASYNC(result_type, header) \ 455 result_type header { \ 456 ThreadInVMfromJavaNoAsyncException __tiv(thread); \ 457 VM_ENTRY_BASE(result_type, header, thread) \ 458 debug_only(VMEntryWrapper __vew;) 459 460 // Same as JRT Entry but allows for return value after the safepoint 461 // to get back into Java from the VM 462 #define JRT_BLOCK_ENTRY(result_type, header) \ 463 result_type header { \ 464 TRACE_CALL(result_type, header) \ 465 HandleMarkCleaner __hm(thread); 466 467 #define JRT_BLOCK \ 468 { \ 469 ThreadInVMfromJava __tiv(thread); \ 470 Thread* THREAD = thread; \ 471 debug_only(VMEntryWrapper __vew;) 472 473 #define JRT_BLOCK_NO_ASYNC \ 474 { \ 475 ThreadInVMfromJavaNoAsyncException __tiv(thread); \ 476 Thread* THREAD = thread; \ 477 debug_only(VMEntryWrapper __vew;) 478 479 #define JRT_BLOCK_END } 480 481 #define JRT_END } 482 483 // Definitions for JNI 484 485 #define JNI_ENTRY(result_type, header) \ 486 JNI_ENTRY_NO_PRESERVE(result_type, header) \ 487 WeakPreserveExceptionMark __wem(thread); 488 489 #define JNI_ENTRY_NO_PRESERVE(result_type, header) \ 490 extern "C" { \ 491 result_type JNICALL header { \ 492 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 493 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \ 494 ThreadInVMfromNative __tiv(thread); \ 495 debug_only(VMNativeEntryWrapper __vew;) \ 496 VM_ENTRY_BASE(result_type, header, thread) 497 498 499 // Ensure that the VMNativeEntryWrapper constructor, which can cause 500 // a GC, is called outside the NoHandleMark (set via VM_QUICK_ENTRY_BASE). 501 #define JNI_QUICK_ENTRY(result_type, header) \ 502 extern "C" { \ 503 result_type JNICALL header { \ 504 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 505 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \ 506 ThreadInVMfromNative __tiv(thread); \ 507 debug_only(VMNativeEntryWrapper __vew;) \ 508 VM_QUICK_ENTRY_BASE(result_type, header, thread) 509 510 511 #define JNI_LEAF(result_type, header) \ 512 extern "C" { \ 513 result_type JNICALL header { \ 514 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 515 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \ 516 VM_LEAF_BASE(result_type, header) 517 518 519 // Close the routine and the extern "C" 520 #define JNI_END } } 521 522 523 524 // Definitions for JVM 525 526 #define JVM_ENTRY(result_type, header) \ 527 extern "C" { \ 528 result_type JNICALL header { \ 529 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 530 ThreadInVMfromNative __tiv(thread); \ 531 debug_only(VMNativeEntryWrapper __vew;) \ 532 VM_ENTRY_BASE(result_type, header, thread) 533 534 535 #define JVM_ENTRY_NO_ENV(result_type, header) \ 536 extern "C" { \ 537 result_type JNICALL header { \ 538 JavaThread* thread = JavaThread::current(); \ 539 ThreadInVMfromNative __tiv(thread); \ 540 debug_only(VMNativeEntryWrapper __vew;) \ 541 VM_ENTRY_BASE(result_type, header, thread) 542 543 544 #define JVM_QUICK_ENTRY(result_type, header) \ 545 extern "C" { \ 546 result_type JNICALL header { \ 547 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 548 ThreadInVMfromNative __tiv(thread); \ 549 debug_only(VMNativeEntryWrapper __vew;) \ 550 VM_QUICK_ENTRY_BASE(result_type, header, thread) 551 552 553 #define JVM_LEAF(result_type, header) \ 554 extern "C" { \ 555 result_type JNICALL header { \ 556 VM_Exit::block_if_vm_exited(); \ 557 VM_LEAF_BASE(result_type, header) 558 559 560 #define JVM_ENTRY_FROM_LEAF(env, result_type, header) \ 561 { { \ 562 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \ 563 ThreadInVMfromNative __tiv(thread); \ 564 debug_only(VMNativeEntryWrapper __vew;) \ 565 VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) 566 567 568 #define JVM_END } } 569 570 #endif // SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP