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/safepoint.hpp"
34 #include "runtime/thread.inline.hpp"
35 #include "runtime/vmThread.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 // The HandleMarkCleaner is a faster version of HandleMark.
42 // It relies on the fact that there is a HandleMark further
43 // down the stack (in JavaCalls::call_helper), and just resets
44 // to the saved values in that HandleMark.
45
46 class HandleMarkCleaner: public StackObj {
47 private:
48 Thread* _thread;
49 public:
50 HandleMarkCleaner(Thread* thread) {
51 _thread = thread;
52 _thread->last_handle_mark()->push();
53 }
54 ~HandleMarkCleaner() {
55 _thread->last_handle_mark()->pop_and_restore();
56 }
57
58 private:
59 inline void* operator new(size_t size, void* ptr) throw() {
60 return ptr;
61 }
62 };
63
64 // InterfaceSupport provides functionality used by the VM_LEAF_BASE and
65 // VM_ENTRY_BASE macros. These macros are used to guard entry points into
66 // the VM and perform checks upon leave of the VM.
67
68
69 class InterfaceSupport: AllStatic {
70 # ifdef ASSERT
71 public:
72 static long _scavenge_alot_counter;
73 static long _fullgc_alot_counter;
74 static long _number_of_calls;
75 static long _fullgc_alot_invocation;
76
77 // Helper methods used to implement +ScavengeALot and +FullGCALot
78 static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); }
79 static void gc_alot();
80
81 static void walk_stack_from(vframe* start_vf);
82 static void walk_stack();
83
84 static void zombieAll();
85 static void unlinkSymbols();
86 static void deoptimizeAll();
87 static void stress_derived_pointers();
88 static void verify_stack();
89 static void verify_last_frame();
90 # endif
91
92 public:
93 // OS dependent stuff
94
95 #include OS_HEADER(interfaceSupport)
96
97 };
98
99
100 // Basic class for all thread transition classes.
101
102 class ThreadStateTransition : public StackObj {
103 protected:
104 JavaThread* _thread;
105 public:
106 ThreadStateTransition(JavaThread *thread) {
107 _thread = thread;
108 assert(thread != NULL && thread->is_Java_thread(), "must be Java thread");
109 }
110
111 // Change threadstate in a manner, so safepoint can detect changes.
112 // Time-critical: called on exit from every runtime routine
113 static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
114 assert(from != _thread_in_Java, "use transition_from_java");
115 assert(from != _thread_in_native, "use transition_from_native");
116 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
117 assert(thread->thread_state() == from, "coming from wrong thread state");
118 // Change to transition state
119 thread->set_thread_state((JavaThreadState)(from + 1));
120
121 // Make sure new state is seen by VM thread
122 if (os::is_MP()) {
123 if (UseMembar) {
124 // Force a fence between the write above and read below
125 OrderAccess::fence();
126 } else {
127 // store to serialize page so VM thread can do pseudo remote membar
128 os::write_memory_serialize_page(thread);
129 }
130 }
131
132 if (SafepointSynchronize::do_call_back()) {
133 SafepointSynchronize::block(thread);
134 }
135 thread->set_thread_state(to);
136
137 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
138 }
139
140 // transition_and_fence must be used on any thread state transition
141 // where there might not be a Java call stub on the stack, in
142 // particular on Windows where the Structured Exception Handler is
143 // set up in the call stub. os::write_memory_serialize_page() can
144 // fault and we can't recover from it on Windows without a SEH in
145 // place.
146 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
147 assert(thread->thread_state() == from, "coming from wrong thread state");
148 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
149 // Change to transition state
150 thread->set_thread_state((JavaThreadState)(from + 1));
151
152 // Make sure new state is seen by VM thread
153 if (os::is_MP()) {
154 if (UseMembar) {
155 // Force a fence between the write above and read below
156 OrderAccess::fence();
157 } else {
158 // Must use this rather than serialization page in particular on Windows
159 InterfaceSupport::serialize_memory(thread);
160 }
161 }
162
163 if (SafepointSynchronize::do_call_back()) {
164 SafepointSynchronize::block(thread);
165 }
166 thread->set_thread_state(to);
167
168 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
169 }
170
171 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we
172 // never block on entry to the VM. This will break the code, since e.g. preserve arguments
173 // have not been setup.
174 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {
175 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");
176 thread->set_thread_state(to);
177 }
178
179 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {
180 assert((to & 1) == 0, "odd numbers are transitions states");
181 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");
182 // Change to transition state
183 thread->set_thread_state(_thread_in_native_trans);
184
185 // Make sure new state is seen by GC thread
186 if (os::is_MP()) {
187 if (UseMembar) {
188 // Force a fence between the write above and read below
189 OrderAccess::fence();
190 } else {
191 // Must use this rather than serialization page in particular on Windows
192 InterfaceSupport::serialize_memory(thread);
193 }
194 }
195
196 // We never install asynchronous exceptions when coming (back) in
197 // to the runtime from native code because the runtime is not set
198 // up to handle exceptions floating around at arbitrary points.
199 if (SafepointSynchronize::do_call_back() || thread->is_suspend_after_native()) {
200 JavaThread::check_safepoint_and_suspend_for_native_trans(thread);
201
202 // Clear unhandled oops anywhere where we could block, even if we don't.
203 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
204 }
205
206 thread->set_thread_state(to);
207 }
208 protected:
209 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); }
210 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); }
211 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); }
212 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); }
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 if (VerifyLastFrame) {
339 InterfaceSupport::verify_last_frame();
340 }
341 }
342
343 ~VMEntryWrapper() {
344 InterfaceSupport::check_gc_alot();
345 if (WalkStackALot) {
346 InterfaceSupport::walk_stack();
347 }
348 #ifdef COMPILER2
349 // This option is not used by Compiler 1
350 if (StressDerivedPointers) {
351 InterfaceSupport::stress_derived_pointers();
352 }
353 #endif
354 if (DeoptimizeALot || DeoptimizeRandom) {
355 InterfaceSupport::deoptimizeAll();
356 }
357 if (ZombieALot) {
358 InterfaceSupport::zombieAll();
359 }
360 if (UnlinkSymbolsALot) {
361 InterfaceSupport::unlinkSymbols();
362 }
363 // do verification AFTER potential deoptimization
364 if (VerifyStack) {
365 InterfaceSupport::verify_stack();
366 }
367
368 }
369 };
370
371
372 class VMNativeEntryWrapper {
373 public:
374 VMNativeEntryWrapper() {
375 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
376 }
377
378 ~VMNativeEntryWrapper() {
379 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
380 }
381 };
382
383 #endif
384
385
386 // VM-internal runtime interface support
387
388 #ifdef ASSERT
389
390 class RuntimeHistogramElement : public HistogramElement {
391 public:
392 RuntimeHistogramElement(const char* name);
393 };
394
395 #define TRACE_CALL(result_type, header) \
396 InterfaceSupport::_number_of_calls++; \
397 if (CountRuntimeCalls) { \
398 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \
399 if (e != NULL) e->increment_count(); \
400 }
401 #else
402 #define TRACE_CALL(result_type, header) \
403 /* do nothing */
404 #endif
405
406
407 // LEAF routines do not lock, GC or throw exceptions
408
409 #define VM_LEAF_BASE(result_type, header) \
410 TRACE_CALL(result_type, header) \
411 debug_only(NoHandleMark __hm;) \
412 os::verify_stack_alignment(); \
413 /* begin of body */
414
415 #define VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) \
416 TRACE_CALL(result_type, header) \
417 debug_only(ResetNoHandleMark __rnhm;) \
418 HandleMarkCleaner __hm(thread); \
419 Thread* THREAD = thread; \
420 os::verify_stack_alignment(); \
421 /* begin of body */
422
423
424 // ENTRY routines may lock, GC and throw exceptions
425
426 #define VM_ENTRY_BASE(result_type, header, thread) \
427 TRACE_CALL(result_type, header) \
428 HandleMarkCleaner __hm(thread); \
429 Thread* THREAD = thread; \
430 os::verify_stack_alignment(); \
431 /* begin of body */
432
433
434 // QUICK_ENTRY routines behave like ENTRY but without a handle mark
435
436 #define VM_QUICK_ENTRY_BASE(result_type, header, thread) \
437 TRACE_CALL(result_type, header) \
438 debug_only(NoHandleMark __hm;) \
439 Thread* THREAD = thread; \
440 os::verify_stack_alignment(); \
441 /* begin of body */
442
443
444 // Definitions for IRT (Interpreter Runtime)
445 // (thread is an argument passed in to all these routines)
446
447 #define IRT_ENTRY(result_type, header) \
448 result_type header { \
449 ThreadInVMfromJava __tiv(thread); \
450 VM_ENTRY_BASE(result_type, header, thread) \
451 debug_only(VMEntryWrapper __vew;)
452
453
454 #define IRT_LEAF(result_type, header) \
455 result_type header { \
456 VM_LEAF_BASE(result_type, header) \
457 debug_only(NoSafepointVerifier __nspv(true);)
458
459
460 #define IRT_ENTRY_NO_ASYNC(result_type, header) \
461 result_type header { \
462 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
463 VM_ENTRY_BASE(result_type, header, thread) \
464 debug_only(VMEntryWrapper __vew;)
465
466 #define IRT_END }
467
468
469 // Definitions for JRT (Java (Compiler/Shared) Runtime)
470
471 #define JRT_ENTRY(result_type, header) \
472 result_type header { \
473 ThreadInVMfromJava __tiv(thread); \
474 VM_ENTRY_BASE(result_type, header, thread) \
475 debug_only(VMEntryWrapper __vew;)
476
477
478 #define JRT_LEAF(result_type, header) \
479 result_type header { \
480 VM_LEAF_BASE(result_type, header) \
481 debug_only(JRTLeafVerifier __jlv;)
482
483
484 #define JRT_ENTRY_NO_ASYNC(result_type, header) \
485 result_type header { \
486 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
487 VM_ENTRY_BASE(result_type, header, thread) \
488 debug_only(VMEntryWrapper __vew;)
489
490 // Same as JRT Entry but allows for return value after the safepoint
491 // to get back into Java from the VM
492 #define JRT_BLOCK_ENTRY(result_type, header) \
493 result_type header { \
494 TRACE_CALL(result_type, header) \
495 HandleMarkCleaner __hm(thread);
496
497 #define JRT_BLOCK \
498 { \
499 ThreadInVMfromJava __tiv(thread); \
500 Thread* THREAD = thread; \
501 debug_only(VMEntryWrapper __vew;)
502
503 #define JRT_BLOCK_NO_ASYNC \
504 { \
505 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
506 Thread* THREAD = thread; \
507 debug_only(VMEntryWrapper __vew;)
508
509 #define JRT_BLOCK_END }
510
511 #define JRT_END }
512
513 // Definitions for JNI
514
515 #define JNI_ENTRY(result_type, header) \
516 JNI_ENTRY_NO_PRESERVE(result_type, header) \
517 WeakPreserveExceptionMark __wem(thread);
518
519 #define JNI_ENTRY_NO_PRESERVE(result_type, header) \
520 extern "C" { \
521 result_type JNICALL header { \
522 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
523 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
524 ThreadInVMfromNative __tiv(thread); \
525 debug_only(VMNativeEntryWrapper __vew;) \
526 VM_ENTRY_BASE(result_type, header, thread)
527
528
529 // Ensure that the VMNativeEntryWrapper constructor, which can cause
530 // a GC, is called outside the NoHandleMark (set via VM_QUICK_ENTRY_BASE).
531 #define JNI_QUICK_ENTRY(result_type, header) \
532 extern "C" { \
533 result_type JNICALL header { \
534 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
535 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
536 ThreadInVMfromNative __tiv(thread); \
537 debug_only(VMNativeEntryWrapper __vew;) \
538 VM_QUICK_ENTRY_BASE(result_type, header, thread)
539
540
541 #define JNI_LEAF(result_type, header) \
542 extern "C" { \
543 result_type JNICALL header { \
544 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
545 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
546 VM_LEAF_BASE(result_type, header)
547
548
549 // Close the routine and the extern "C"
550 #define JNI_END } }
551
552
553
554 // Definitions for JVM
555
556 #define JVM_ENTRY(result_type, header) \
557 extern "C" { \
558 result_type JNICALL header { \
559 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
560 ThreadInVMfromNative __tiv(thread); \
561 debug_only(VMNativeEntryWrapper __vew;) \
562 VM_ENTRY_BASE(result_type, header, thread)
563
564
565 #define JVM_ENTRY_NO_ENV(result_type, header) \
566 extern "C" { \
567 result_type JNICALL header { \
568 JavaThread* thread = JavaThread::current(); \
569 ThreadInVMfromNative __tiv(thread); \
570 debug_only(VMNativeEntryWrapper __vew;) \
571 VM_ENTRY_BASE(result_type, header, thread)
572
573
574 #define JVM_QUICK_ENTRY(result_type, header) \
575 extern "C" { \
576 result_type JNICALL header { \
577 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
578 ThreadInVMfromNative __tiv(thread); \
579 debug_only(VMNativeEntryWrapper __vew;) \
580 VM_QUICK_ENTRY_BASE(result_type, header, thread)
581
582
583 #define JVM_LEAF(result_type, header) \
584 extern "C" { \
585 result_type JNICALL header { \
586 VM_Exit::block_if_vm_exited(); \
587 VM_LEAF_BASE(result_type, header)
588
589
590 #define JVM_ENTRY_FROM_LEAF(env, result_type, header) \
591 { { \
592 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
593 ThreadInVMfromNative __tiv(thread); \
594 debug_only(VMNativeEntryWrapper __vew;) \
595 VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread)
596
597
598 #define JVM_END } }
599
600 #endif // SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP