1 /*
2 * Copyright (c) 1997, 2012, 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/thread.inline.hpp"
35 #include "runtime/vmThread.hpp"
36 #include "utilities/globalDefinitions.hpp"
37 #include "utilities/preserveException.hpp"
38 #include "utilities/top.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) {
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 // tracing
78 static void trace(const char* result_type, const char* header);
79
80 // Helper methods used to implement +ScavengeALot and +FullGCALot
81 static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); }
82 static void gc_alot();
83
84 static void walk_stack_from(vframe* start_vf);
85 static void walk_stack();
86
87 # ifdef ENABLE_ZAP_DEAD_LOCALS
88 static void zap_dead_locals_old();
89 # endif
90
91 static void zombieAll();
92 static void unlinkSymbols();
93 static void deoptimizeAll();
94 static void stress_derived_pointers();
95 static void verify_stack();
96 static void verify_last_frame();
97 # endif
98
99 public:
100 // OS dependent stuff
101 #ifdef TARGET_OS_FAMILY_linux
102 # include "interfaceSupport_linux.hpp"
103 #endif
104 #ifdef TARGET_OS_FAMILY_solaris
105 # include "interfaceSupport_solaris.hpp"
106 #endif
107 #ifdef TARGET_OS_FAMILY_windows
108 # include "interfaceSupport_windows.hpp"
109 #endif
110 #ifdef TARGET_OS_FAMILY_bsd
111 # include "interfaceSupport_bsd.hpp"
112 #endif
113
114 };
115
116
117 // Basic class for all thread transition classes.
118
119 class ThreadStateTransition : public StackObj {
120 protected:
121 JavaThread* _thread;
122 public:
123 ThreadStateTransition(JavaThread *thread) {
124 _thread = thread;
125 assert(thread != NULL && thread->is_Java_thread(), "must be Java thread");
126 }
127
128 // Change threadstate in a manner, so safepoint can detect changes.
129 // Time-critical: called on exit from every runtime routine
130 static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
131 assert(from != _thread_in_Java, "use transition_from_java");
132 assert(from != _thread_in_native, "use transition_from_native");
133 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
134 assert(thread->thread_state() == from, "coming from wrong thread state");
135 // Change to transition state (assumes total store ordering! -Urs)
136 thread->set_thread_state((JavaThreadState)(from + 1));
137
138 // Make sure new state is seen by VM thread
139 if (os::is_MP()) {
140 if (UseMembar) {
141 // Force a fence between the write above and read below
142 OrderAccess::fence();
143 } else {
144 // store to serialize page so VM thread can do pseudo remote membar
145 os::write_memory_serialize_page(thread);
146 }
147 }
148
149 if (SafepointSynchronize::do_call_back()) {
150 SafepointSynchronize::block(thread);
151 }
152 thread->set_thread_state(to);
153
154 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
155 }
156
157 // transition_and_fence must be used on any thread state transition
158 // where there might not be a Java call stub on the stack, in
159 // particular on Windows where the Structured Exception Handler is
160 // set up in the call stub. os::write_memory_serialize_page() can
161 // fault and we can't recover from it on Windows without a SEH in
162 // place.
163 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
164 assert(thread->thread_state() == from, "coming from wrong thread state");
165 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
166 // Change to transition state (assumes total store ordering! -Urs)
167 thread->set_thread_state((JavaThreadState)(from + 1));
168
169 // Make sure new state is seen by VM thread
170 if (os::is_MP()) {
171 if (UseMembar) {
172 // Force a fence between the write above and read below
173 OrderAccess::fence();
174 } else {
175 // Must use this rather than serialization page in particular on Windows
176 InterfaceSupport::serialize_memory(thread);
177 }
178 }
179
180 if (SafepointSynchronize::do_call_back()) {
181 SafepointSynchronize::block(thread);
182 }
183 thread->set_thread_state(to);
184
185 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
186 }
187
188 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we
189 // never block on entry to the VM. This will break the code, since e.g. preserve arguments
190 // have not been setup.
191 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {
192 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");
193 thread->set_thread_state(to);
194 }
195
196 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {
197 assert((to & 1) == 0, "odd numbers are transitions states");
198 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");
199 // Change to transition state (assumes total store ordering! -Urs)
200 thread->set_thread_state(_thread_in_native_trans);
201
202 // Make sure new state is seen by GC thread
203 if (os::is_MP()) {
204 if (UseMembar) {
205 // Force a fence between the write above and read below
206 OrderAccess::fence();
207 } else {
208 // Must use this rather than serialization page in particular on Windows
209 InterfaceSupport::serialize_memory(thread);
210 }
211 }
212
213 // We never install asynchronous exceptions when coming (back) in
214 // to the runtime from native code because the runtime is not set
215 // up to handle exceptions floating around at arbitrary points.
216 if (SafepointSynchronize::do_call_back() || thread->is_suspend_after_native()) {
217 JavaThread::check_safepoint_and_suspend_for_native_trans(thread);
218
219 // Clear unhandled oops anywhere where we could block, even if we don't.
220 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
221 }
222
223 thread->set_thread_state(to);
224 }
225 protected:
226 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); }
227 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); }
228 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); }
229 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); }
230 };
231
232
233 class ThreadInVMfromJava : public ThreadStateTransition {
234 public:
235 ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) {
236 trans_from_java(_thread_in_vm);
237 }
238 ~ThreadInVMfromJava() {
239 trans(_thread_in_vm, _thread_in_Java);
240 // Check for pending. async. exceptions or suspends.
241 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition();
242 }
243 };
244
245
246 class ThreadInVMfromUnknown {
247 private:
248 JavaThread* _thread;
249 public:
250 ThreadInVMfromUnknown() : _thread(NULL) {
251 Thread* t = Thread::current();
252 if (t->is_Java_thread()) {
253 JavaThread* t2 = (JavaThread*) t;
254 if (t2->thread_state() == _thread_in_native) {
255 _thread = t2;
256 ThreadStateTransition::transition_from_native(t2, _thread_in_vm);
257 // Used to have a HandleMarkCleaner but that is dangerous as
258 // it could free a handle in our (indirect, nested) caller.
259 // We expect any handles will be short lived and figure we
260 // don't need an actual HandleMark.
261 }
262 }
263 }
264 ~ThreadInVMfromUnknown() {
265 if (_thread) {
266 ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native);
267 }
268 }
269 };
270
271
272 class ThreadInVMfromNative : public ThreadStateTransition {
273 public:
274 ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) {
275 trans_from_native(_thread_in_vm);
276 }
277 ~ThreadInVMfromNative() {
278 trans_and_fence(_thread_in_vm, _thread_in_native);
279 }
280 };
281
282
283 class ThreadToNativeFromVM : public ThreadStateTransition {
284 public:
285 ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {
286 // We are leaving the VM at this point and going directly to native code.
287 // Block, if we are in the middle of a safepoint synchronization.
288 assert(!thread->owns_locks(), "must release all locks when leaving VM");
289 thread->frame_anchor()->make_walkable(thread);
290 trans_and_fence(_thread_in_vm, _thread_in_native);
291 // Check for pending. async. exceptions or suspends.
292 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false);
293 }
294
295 ~ThreadToNativeFromVM() {
296 trans_from_native(_thread_in_vm);
297 // We don't need to clear_walkable because it will happen automagically when we return to java
298 }
299 };
300
301
302 class ThreadBlockInVM : public ThreadStateTransition {
303 public:
304 ThreadBlockInVM(JavaThread *thread)
305 : ThreadStateTransition(thread) {
306 // Once we are blocked vm expects stack to be walkable
307 thread->frame_anchor()->make_walkable(thread);
308 trans_and_fence(_thread_in_vm, _thread_blocked);
309 }
310 ~ThreadBlockInVM() {
311 trans_and_fence(_thread_blocked, _thread_in_vm);
312 // We don't need to clear_walkable because it will happen automagically when we return to java
313 }
314 };
315
316
317 // This special transition class is only used to prevent asynchronous exceptions
318 // from being installed on vm exit in situations where we can't tolerate them.
319 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705.
320 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition {
321 public:
322 ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) {
323 trans_from_java(_thread_in_vm);
324 }
325 ~ThreadInVMfromJavaNoAsyncException() {
326 trans(_thread_in_vm, _thread_in_Java);
327 // NOTE: We do not check for pending. async. exceptions.
328 // If we did and moved the pending async exception over into the
329 // pending exception field, we would need to deopt (currently C2
330 // only). However, to do so would require that we transition back
331 // to the _thread_in_vm state. Instead we postpone the handling of
332 // the async exception.
333
334 // Check for pending. suspends only.
335 if (_thread->has_special_runtime_exit_condition())
336 _thread->handle_special_runtime_exit_condition(false);
337 }
338 };
339
340 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro.
341 // Can be used to verify properties on enter/exit of the VM.
342
343 #ifdef ASSERT
344 class VMEntryWrapper {
345 public:
346 VMEntryWrapper() {
347 if (VerifyLastFrame) {
348 InterfaceSupport::verify_last_frame();
349 }
350 }
351
352 ~VMEntryWrapper() {
353 InterfaceSupport::check_gc_alot();
354 if (WalkStackALot) {
355 InterfaceSupport::walk_stack();
356 }
357 #ifdef ENABLE_ZAP_DEAD_LOCALS
358 if (ZapDeadLocalsOld) {
359 InterfaceSupport::zap_dead_locals_old();
360 }
361 #endif
362 #ifdef COMPILER2
363 // This option is not used by Compiler 1
364 if (StressDerivedPointers) {
365 InterfaceSupport::stress_derived_pointers();
366 }
367 #endif
368 if (DeoptimizeALot || DeoptimizeRandom) {
369 InterfaceSupport::deoptimizeAll();
370 }
371 if (ZombieALot) {
372 InterfaceSupport::zombieAll();
373 }
374 if (UnlinkSymbolsALot) {
375 InterfaceSupport::unlinkSymbols();
376 }
377 // do verification AFTER potential deoptimization
378 if (VerifyStack) {
379 InterfaceSupport::verify_stack();
380 }
381
382 }
383 };
384
385
386 class VMNativeEntryWrapper {
387 public:
388 VMNativeEntryWrapper() {
389 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
390 }
391
392 ~VMNativeEntryWrapper() {
393 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
394 }
395 };
396
397 #endif
398
399
400 // VM-internal runtime interface support
401
402 #ifdef ASSERT
403
404 class RuntimeHistogramElement : public HistogramElement {
405 public:
406 RuntimeHistogramElement(const char* name);
407 };
408
409 #define TRACE_CALL(result_type, header) \
410 InterfaceSupport::_number_of_calls++; \
411 if (TraceRuntimeCalls) \
412 InterfaceSupport::trace(#result_type, #header); \
413 if (CountRuntimeCalls) { \
414 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \
415 if (e != NULL) e->increment_count(); \
416 }
417 #else
418 #define TRACE_CALL(result_type, header) \
419 /* do nothing */
420 #endif
421
422
423 // LEAF routines do not lock, GC or throw exceptions
424
425 #define VM_LEAF_BASE(result_type, header) \
426 TRACE_CALL(result_type, header) \
427 debug_only(NoHandleMark __hm;) \
428 os::verify_stack_alignment(); \
429 /* begin of body */
430
431
432 // ENTRY routines may lock, GC and throw exceptions
433
434 #define VM_ENTRY_BASE(result_type, header, thread) \
435 TRACE_CALL(result_type, header) \
436 HandleMarkCleaner __hm(thread); \
437 Thread* THREAD = thread; \
438 os::verify_stack_alignment(); \
439 /* begin of body */
440
441
442 // QUICK_ENTRY routines behave like ENTRY but without a handle mark
443
444 #define VM_QUICK_ENTRY_BASE(result_type, header, thread) \
445 TRACE_CALL(result_type, header) \
446 debug_only(NoHandleMark __hm;) \
447 Thread* THREAD = thread; \
448 os::verify_stack_alignment(); \
449 /* begin of body */
450
451
452 // Definitions for IRT (Interpreter Runtime)
453 // (thread is an argument passed in to all these routines)
454
455 #define IRT_ENTRY(result_type, header) \
456 result_type header { \
457 ThreadInVMfromJava __tiv(thread); \
458 VM_ENTRY_BASE(result_type, header, thread) \
459 debug_only(VMEntryWrapper __vew;)
460
461
462 #define IRT_LEAF(result_type, header) \
463 result_type header { \
464 VM_LEAF_BASE(result_type, header) \
465 debug_only(No_Safepoint_Verifier __nspv(true);)
466
467
468 #define IRT_ENTRY_NO_ASYNC(result_type, header) \
469 result_type header { \
470 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
471 VM_ENTRY_BASE(result_type, header, thread) \
472 debug_only(VMEntryWrapper __vew;)
473
474 // Another special case for nmethod_entry_point so the nmethod that the
475 // interpreter is about to branch to doesn't get flushed before as we
476 // branch to it's interpreter_entry_point. Skip stress testing here too.
477 // Also we don't allow async exceptions because it is just too painful.
478 #define IRT_ENTRY_FOR_NMETHOD(result_type, header) \
479 result_type header { \
480 nmethodLocker _nmlock(nm); \
481 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
482 VM_ENTRY_BASE(result_type, header, thread)
483
484 #define IRT_END }
485
486
487 // Definitions for JRT (Java (Compiler/Shared) Runtime)
488
489 #define JRT_ENTRY(result_type, header) \
490 result_type header { \
491 ThreadInVMfromJava __tiv(thread); \
492 VM_ENTRY_BASE(result_type, header, thread) \
493 debug_only(VMEntryWrapper __vew;)
494
495
496 #define JRT_LEAF(result_type, header) \
497 result_type header { \
498 VM_LEAF_BASE(result_type, header) \
499 debug_only(JRT_Leaf_Verifier __jlv;)
500
501
502 #define JRT_ENTRY_NO_ASYNC(result_type, header) \
503 result_type header { \
504 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
505 VM_ENTRY_BASE(result_type, header, thread) \
506 debug_only(VMEntryWrapper __vew;)
507
508 // Same as JRT Entry but allows for return value after the safepoint
509 // to get back into Java from the VM
510 #define JRT_BLOCK_ENTRY(result_type, header) \
511 result_type header { \
512 TRACE_CALL(result_type, header) \
513 HandleMarkCleaner __hm(thread);
514
515 #define JRT_BLOCK \
516 { \
517 ThreadInVMfromJava __tiv(thread); \
518 Thread* THREAD = thread; \
519 debug_only(VMEntryWrapper __vew;)
520
521 #define JRT_BLOCK_END }
522
523 #define JRT_END }
524
525 // Definitions for JNI
526
527 #define JNI_ENTRY(result_type, header) \
528 JNI_ENTRY_NO_PRESERVE(result_type, header) \
529 WeakPreserveExceptionMark __wem(thread);
530
531 #define JNI_ENTRY_NO_PRESERVE(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_ENTRY_BASE(result_type, header, thread)
539
540
541 // Ensure that the VMNativeEntryWrapper constructor, which can cause
542 // a GC, is called outside the NoHandleMark (set via VM_QUICK_ENTRY_BASE).
543 #define JNI_QUICK_ENTRY(result_type, header) \
544 extern "C" { \
545 result_type JNICALL header { \
546 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
547 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
548 ThreadInVMfromNative __tiv(thread); \
549 debug_only(VMNativeEntryWrapper __vew;) \
550 VM_QUICK_ENTRY_BASE(result_type, header, thread)
551
552
553 #define JNI_LEAF(result_type, header) \
554 extern "C" { \
555 result_type JNICALL header { \
556 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
557 assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
558 VM_LEAF_BASE(result_type, header)
559
560
561 // Close the routine and the extern "C"
562 #define JNI_END } }
563
564
565
566 // Definitions for JVM
567
568 #define JVM_ENTRY(result_type, header) \
569 extern "C" { \
570 result_type JNICALL header { \
571 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
572 ThreadInVMfromNative __tiv(thread); \
573 debug_only(VMNativeEntryWrapper __vew;) \
574 VM_ENTRY_BASE(result_type, header, thread)
575
576
577 #define JVM_ENTRY_NO_ENV(result_type, header) \
578 extern "C" { \
579 result_type JNICALL header { \
580 JavaThread* thread = (JavaThread*)ThreadLocalStorage::thread(); \
581 ThreadInVMfromNative __tiv(thread); \
582 debug_only(VMNativeEntryWrapper __vew;) \
583 VM_ENTRY_BASE(result_type, header, thread)
584
585
586 #define JVM_QUICK_ENTRY(result_type, header) \
587 extern "C" { \
588 result_type JNICALL header { \
589 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
590 ThreadInVMfromNative __tiv(thread); \
591 debug_only(VMNativeEntryWrapper __vew;) \
592 VM_QUICK_ENTRY_BASE(result_type, header, thread)
593
594
595 #define JVM_LEAF(result_type, header) \
596 extern "C" { \
597 result_type JNICALL header { \
598 VM_Exit::block_if_vm_exited(); \
599 VM_LEAF_BASE(result_type, header)
600
601
602 #define JVM_END } }
603
604 #endif // SHARE_VM_RUNTIME_INTERFACESUPPORT_HPP