1 /*
2 * Copyright (c) 1997, 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 #ifndef SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP
26 #define SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP
27
28 #include "memory/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/vmThread.hpp"
35 #include "utilities/globalDefinitions.hpp"
36 #include "utilities/preserveException.hpp"
37 #include "utilities/top.hpp"
38 #ifdef TARGET_OS_FAMILY_linux
39 # include "thread_linux.inline.hpp"
40 #endif
41 #ifdef TARGET_OS_FAMILY_solaris
42 # include "thread_solaris.inline.hpp"
43 #endif
44 #ifdef TARGET_OS_FAMILY_windows
45 # include "thread_windows.inline.hpp"
46 #endif
47
48 // Wrapper for all entry points to the virtual machine.
49 // The HandleMarkCleaner is a faster version of HandleMark.
50 // It relies on the fact that there is a HandleMark further
51 // down the stack (in JavaCalls::call_helper), and just resets
52 // to the saved values in that HandleMark.
53
54 class HandleMarkCleaner: public StackObj {
55 private:
56 Thread* _thread;
57 public:
58 HandleMarkCleaner(Thread* thread) {
59 _thread = thread;
60 _thread->last_handle_mark()->push();
61 }
62 ~HandleMarkCleaner() {
63 _thread->last_handle_mark()->pop_and_restore();
64 }
65
66 private:
67 inline void* operator new(size_t size, void* ptr) {
68 return ptr;
69 }
70 };
71
72 // InterfaceSupport provides functionality used by the __LEAF and __ENTRY
73 // macros. These macros are used to guard entry points into the VM and
74 // perform checks upon leave of the VM.
75
76
77 class InterfaceSupport: AllStatic {
78 # ifdef ASSERT
79 public:
80 static long _scavenge_alot_counter;
81 static long _fullgc_alot_counter;
82 static long _number_of_calls;
83 static long _fullgc_alot_invocation;
84
85 // tracing
86 static void trace(const char* result_type, const char* header);
87
88 // Helper methods used to implement +ScavengeALot and +FullGCALot
89 static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); }
90 static void gc_alot();
91
92 static void walk_stack_from(vframe* start_vf);
93 static void walk_stack();
94
95 # ifdef ENABLE_ZAP_DEAD_LOCALS
96 static void zap_dead_locals_old();
97 # endif
98
99 static void zombieAll();
100 static void deoptimizeAll();
101 static void stress_derived_pointers();
102 static void verify_stack();
103 static void verify_last_frame();
104 # endif
105
106 public:
107 // OS dependent stuff
108 #ifdef TARGET_OS_FAMILY_linux
109 # include "interfaceSupport_linux.hpp"
110 #endif
111 #ifdef TARGET_OS_FAMILY_solaris
112 # include "interfaceSupport_solaris.hpp"
113 #endif
114 #ifdef TARGET_OS_FAMILY_windows
115 # include "interfaceSupport_windows.hpp"
116 #endif
117
118 };
119
120
121 // Basic class for all thread transition classes.
122
123 class ThreadStateTransition : public StackObj {
124 protected:
125 JavaThread* _thread;
126 public:
127 ThreadStateTransition(JavaThread *thread) {
128 _thread = thread;
129 assert(thread != NULL && thread->is_Java_thread(), "must be Java thread");
130 }
131
132 // Change threadstate in a manner, so safepoint can detect changes.
133 // Time-critical: called on exit from every runtime routine
134 static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
135 assert(from != _thread_in_Java, "use transition_from_java");
136 assert(from != _thread_in_native, "use transition_from_native");
137 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
138 assert(thread->thread_state() == from, "coming from wrong thread state");
139 // Change to transition state (assumes total store ordering! -Urs)
140 thread->set_thread_state((JavaThreadState)(from + 1));
141
142 // Make sure new state is seen by VM thread
143 if (os::is_MP()) {
144 if (UseMembar) {
145 // Force a fence between the write above and read below
146 OrderAccess::fence();
147 } else {
148 // store to serialize page so VM thread can do pseudo remote membar
149 os::write_memory_serialize_page(thread);
150 }
151 }
152
153 if (SafepointSynchronize::do_call_back()) {
154 SafepointSynchronize::block(thread);
155 }
156 thread->set_thread_state(to);
157
158 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
159 }
160
161 // transition_and_fence must be used on any thread state transition
162 // where there might not be a Java call stub on the stack, in
163 // particular on Windows where the Structured Exception Handler is
164 // set up in the call stub. os::write_memory_serialize_page() can
165 // fault and we can't recover from it on Windows without a SEH in
166 // place.
167 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
168 assert(thread->thread_state() == from, "coming from wrong thread state");
169 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
170 // Change to transition state (assumes total store ordering! -Urs)
171 thread->set_thread_state((JavaThreadState)(from + 1));
172
173 // Make sure new state is seen by VM thread
174 if (os::is_MP()) {
175 if (UseMembar) {
176 // Force a fence between the write above and read below
177 OrderAccess::fence();
178 } else {
179 // Must use this rather than serialization page in particular on Windows
180 InterfaceSupport::serialize_memory(thread);
181 }
182 }
183
184 if (SafepointSynchronize::do_call_back()) {
185 SafepointSynchronize::block(thread);
186 }
187 thread->set_thread_state(to);
188
189 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
190 }
191
192 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we
193 // never block on entry to the VM. This will break the code, since e.g. preserve arguments
194 // have not been setup.
195 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {
196 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");
197 thread->set_thread_state(to);
198 }
199
200 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {
201 assert((to & 1) == 0, "odd numbers are transitions states");
202 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");
203 // Change to transition state (assumes total store ordering! -Urs)
204 thread->set_thread_state(_thread_in_native_trans);
205
206 // Make sure new state is seen by GC thread
207 if (os::is_MP()) {
208 if (UseMembar) {
209 // Force a fence between the write above and read below
210 OrderAccess::fence();
211 } else {
212 // Must use this rather than serialization page in particular on Windows
213 InterfaceSupport::serialize_memory(thread);
214 }
215 }
216
217 // We never install asynchronous exceptions when coming (back) in
218 // to the runtime from native code because the runtime is not set
219 // up to handle exceptions floating around at arbitrary points.
220 if (SafepointSynchronize::do_call_back() || thread->is_suspend_after_native()) {
221 JavaThread::check_safepoint_and_suspend_for_native_trans(thread);
222
223 // Clear unhandled oops anywhere where we could block, even if we don't.
224 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
225 }
226
227 thread->set_thread_state(to);
228 }
229 protected:
230 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); }
231 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); }
232 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); }
233 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); }
234 };
235
236
237 class ThreadInVMfromJava : public ThreadStateTransition {
238 public:
239 ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) {
240 trans_from_java(_thread_in_vm);
241 }
242 ~ThreadInVMfromJava() {
243 trans(_thread_in_vm, _thread_in_Java);
244 // Check for pending. async. exceptions or suspends.
245 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition();
246 }
247 };
248
249
250 class ThreadInVMfromUnknown {
251 private:
252 JavaThread* _thread;
253 public:
254 ThreadInVMfromUnknown() : _thread(NULL) {
255 Thread* t = Thread::current();
256 if (t->is_Java_thread()) {
257 JavaThread* t2 = (JavaThread*) t;
258 if (t2->thread_state() == _thread_in_native) {
259 _thread = t2;
260 ThreadStateTransition::transition_from_native(t2, _thread_in_vm);
261 // Used to have a HandleMarkCleaner but that is dangerous as
262 // it could free a handle in our (indirect, nested) caller.
263 // We expect any handles will be short lived and figure we
264 // don't need an actual HandleMark.
265 }
266 }
267 }
268 ~ThreadInVMfromUnknown() {
269 if (_thread) {
270 ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native);
271 }
272 }
273 };
274
275
276 class ThreadInVMfromNative : public ThreadStateTransition {
277 public:
278 ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) {
279 trans_from_native(_thread_in_vm);
280 }
281 ~ThreadInVMfromNative() {
282 trans_and_fence(_thread_in_vm, _thread_in_native);
283 }
284 };
285
286
287 class ThreadToNativeFromVM : public ThreadStateTransition {
288 public:
289 ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {
290 // We are leaving the VM at this point and going directly to native code.
291 // Block, if we are in the middle of a safepoint synchronization.
292 assert(!thread->owns_locks(), "must release all locks when leaving VM");
293 thread->frame_anchor()->make_walkable(thread);
294 trans_and_fence(_thread_in_vm, _thread_in_native);
295 // Check for pending. async. exceptions or suspends.
296 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false);
297 }
298
299 ~ThreadToNativeFromVM() {
300 trans_from_native(_thread_in_vm);
301 // We don't need to clear_walkable because it will happen automagically when we return to java
302 }
303 };
304
305
306 class ThreadBlockInVM : public ThreadStateTransition {
307 public:
308 ThreadBlockInVM(JavaThread *thread)
309 : ThreadStateTransition(thread) {
310 // Once we are blocked vm expects stack to be walkable
311 thread->frame_anchor()->make_walkable(thread);
312 trans_and_fence(_thread_in_vm, _thread_blocked);
313 }
314 ~ThreadBlockInVM() {
315 trans_and_fence(_thread_blocked, _thread_in_vm);
316 // We don't need to clear_walkable because it will happen automagically when we return to java
317 }
318 };
319
320
321 // This special transition class is only used to prevent asynchronous exceptions
322 // from being installed on vm exit in situations where we can't tolerate them.
323 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705.
324 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition {
325 public:
326 ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) {
327 trans_from_java(_thread_in_vm);
328 }
329 ~ThreadInVMfromJavaNoAsyncException() {
330 trans(_thread_in_vm, _thread_in_Java);
331 // NOTE: We do not check for pending. async. exceptions.
332 // If we did and moved the pending async exception over into the
333 // pending exception field, we would need to deopt (currently C2
334 // only). However, to do so would require that we transition back
335 // to the _thread_in_vm state. Instead we postpone the handling of
336 // the async exception.
337
338 // Check for pending. suspends only.
339 if (_thread->has_special_runtime_exit_condition())
340 _thread->handle_special_runtime_exit_condition(false);
341 }
342 };
343
344 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro.
345 // Can be used to verify properties on enter/exit of the VM.
346
347 #ifdef ASSERT
348 class VMEntryWrapper {
349 public:
350 VMEntryWrapper() {
351 if (VerifyLastFrame) {
352 InterfaceSupport::verify_last_frame();
353 }
354 }
355
356 ~VMEntryWrapper() {
357 InterfaceSupport::check_gc_alot();
358 if (WalkStackALot) {
359 InterfaceSupport::walk_stack();
360 }
361 #ifdef ENABLE_ZAP_DEAD_LOCALS
362 if (ZapDeadLocalsOld) {
363 InterfaceSupport::zap_dead_locals_old();
364 }
365 #endif
366 #ifdef COMPILER2
367 // This option is not used by Compiler 1
368 if (StressDerivedPointers) {
369 InterfaceSupport::stress_derived_pointers();
370 }
371 #endif
372 if (DeoptimizeALot || DeoptimizeRandom) {
373 InterfaceSupport::deoptimizeAll();
374 }
375 if (ZombieALot) {
376 InterfaceSupport::zombieAll();
377 }
378 // do verification AFTER potential deoptimization
379 if (VerifyStack) {
380 InterfaceSupport::verify_stack();
381 }
382
383 }
384 };
385
386
387 class VMNativeEntryWrapper {
388 public:
389 VMNativeEntryWrapper() {
390 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
391 }
392
393 ~VMNativeEntryWrapper() {
394 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
395 }
396 };
397
398 #endif
399
400
401 // VM-internal runtime interface support
402
403 #ifdef ASSERT
404
405 class RuntimeHistogramElement : public HistogramElement {
406 public:
407 RuntimeHistogramElement(const char* name);
408 };
409
410 #define TRACE_CALL(result_type, header) \
411 InterfaceSupport::_number_of_calls++; \
412 if (TraceRuntimeCalls) \
413 InterfaceSupport::trace(#result_type, #header); \
414 if (CountRuntimeCalls) { \
415 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \
416 if (e != NULL) e->increment_count(); \
417 }
418 #else
419 #define TRACE_CALL(result_type, header) \
420 /* do nothing */
421 #endif
422
423
424 // LEAF routines do not lock, GC or throw exceptions
425
426 #define __LEAF(result_type, header) \
427 TRACE_CALL(result_type, header) \
428 debug_only(NoHandleMark __hm;) \
429 /* begin of body */
430
431
432 // ENTRY routines may lock, GC and throw exceptions
433
434 #define __ENTRY(result_type, header, thread) \
435 TRACE_CALL(result_type, header) \
436 HandleMarkCleaner __hm(thread); \
437 Thread* THREAD = thread; \
438 /* begin of body */
439
440
441 // QUICK_ENTRY routines behave like ENTRY but without a handle mark
442
443 #define __QUICK_ENTRY(result_type, header, thread) \
444 TRACE_CALL(result_type, header) \
445 debug_only(NoHandleMark __hm;) \
446 Thread* THREAD = thread; \
447 /* begin of body */
448
449
450 // Definitions for IRT (Interpreter Runtime)
451 // (thread is an argument passed in to all these routines)
452
453 #define IRT_ENTRY(result_type, header) \
454 result_type header { \
455 ThreadInVMfromJava __tiv(thread); \
456 __ENTRY(result_type, header, thread) \
457 debug_only(VMEntryWrapper __vew;)
458
459
460 #define IRT_LEAF(result_type, header) \
461 result_type header { \
462 __LEAF(result_type, header) \
463 debug_only(No_Safepoint_Verifier __nspv(true);)
464
465
466 #define IRT_ENTRY_NO_ASYNC(result_type, header) \
467 result_type header { \
468 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
469 __ENTRY(result_type, header, thread) \
470 debug_only(VMEntryWrapper __vew;)
471
472 // Another special case for nmethod_entry_point so the nmethod that the
473 // interpreter is about to branch to doesn't get flushed before as we
474 // branch to it's interpreter_entry_point. Skip stress testing here too.
475 // Also we don't allow async exceptions because it is just too painful.
476 #define IRT_ENTRY_FOR_NMETHOD(result_type, header) \
477 result_type header { \
478 nmethodLocker _nmlock(nm); \
479 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
480 __ENTRY(result_type, header, thread)
481
482 #define IRT_END }
483
484
485 // Definitions for JRT (Java (Compiler/Shared) Runtime)
486
487 #define JRT_ENTRY(result_type, header) \
488 result_type header { \
489 ThreadInVMfromJava __tiv(thread); \
490 __ENTRY(result_type, header, thread) \
491 debug_only(VMEntryWrapper __vew;)
492
493
494 #define JRT_LEAF(result_type, header) \
495 result_type header { \
496 __LEAF(result_type, header) \
497 debug_only(JRT_Leaf_Verifier __jlv;)
498
499
500 #define JRT_ENTRY_NO_ASYNC(result_type, header) \
501 result_type header { \
502 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
503 __ENTRY(result_type, header, thread) \
504 debug_only(VMEntryWrapper __vew;)
505
506 // Same as JRT Entry but allows for return value after the safepoint
507 // to get back into Java from the VM
508 #define JRT_BLOCK_ENTRY(result_type, header) \
509 result_type header { \
510 TRACE_CALL(result_type, header) \
511 HandleMarkCleaner __hm(thread);
512
513 #define JRT_BLOCK \
514 { \
515 ThreadInVMfromJava __tiv(thread); \
516 Thread* THREAD = thread; \
517 debug_only(VMEntryWrapper __vew;)
518
519 #define JRT_BLOCK_END }
520
521 #define JRT_END }
522
523 // Definitions for JNI
524
525 #define JNI_ENTRY(result_type, header) \
526 JNI_ENTRY_NO_PRESERVE(result_type, header) \
527 WeakPreserveExceptionMark __wem(thread);
528
529 #define JNI_ENTRY_NO_PRESERVE(result_type, header) \
530 extern "C" { \
531 result_type JNICALL header { \
532 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
533 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
534 ThreadInVMfromNative __tiv(thread); \
535 debug_only(VMNativeEntryWrapper __vew;) \
536 __ENTRY(result_type, header, thread)
537
538
539 // Ensure that the VMNativeEntryWrapper constructor, which can cause
540 // a GC, is called outside the NoHandleMark (set via __QUICK_ENTRY).
541 #define JNI_QUICK_ENTRY(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 ThreadInVMfromNative __tiv(thread); \
547 debug_only(VMNativeEntryWrapper __vew;) \
548 __QUICK_ENTRY(result_type, header, thread)
549
550
551 #define JNI_LEAF(result_type, header) \
552 extern "C" { \
553 result_type JNICALL header { \
554 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
555 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
556 __LEAF(result_type, header)
557
558
559 // Close the routine and the extern "C"
560 #define JNI_END } }
561
562
563
564 // Definitions for JVM
565
566 #define JVM_ENTRY(result_type, header) \
567 extern "C" { \
568 result_type JNICALL header { \
569 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
570 ThreadInVMfromNative __tiv(thread); \
571 debug_only(VMNativeEntryWrapper __vew;) \
572 __ENTRY(result_type, header, thread)
573
574
575 #define JVM_ENTRY_NO_ENV(result_type, header) \
576 extern "C" { \
577 result_type JNICALL header { \
578 JavaThread* thread = (JavaThread*)ThreadLocalStorage::thread(); \
579 ThreadInVMfromNative __tiv(thread); \
580 debug_only(VMNativeEntryWrapper __vew;) \
581 __ENTRY(result_type, header, thread)
582
583
584 #define JVM_QUICK_ENTRY(result_type, header) \
585 extern "C" { \
586 result_type JNICALL header { \
587 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
588 ThreadInVMfromNative __tiv(thread); \
589 debug_only(VMNativeEntryWrapper __vew;) \
590 __QUICK_ENTRY(result_type, header, thread)
591
592
593 #define JVM_LEAF(result_type, header) \
594 extern "C" { \
595 result_type JNICALL header { \
596 VM_Exit::block_if_vm_exited(); \
597 __LEAF(result_type, header)
598
599
600 #define JVM_END } }
601
602 #endif // SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP