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_INLINE_HPP
26 #define SHARE_VM_RUNTIME_INTERFACESUPPORT_INLINE_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 "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 unlinkSymbols();
64 static void deoptimizeAll();
65 static void stress_derived_pointers();
66 static void verify_stack();
67 static void verify_last_frame();
68 # endif
69
70 public:
71 static void serialize_thread_state_with_handler(JavaThread* thread) {
72 serialize_thread_state_internal(thread, true);
73 }
74
75 // Should only call this if we know that we have a proper SEH set up.
76 static void serialize_thread_state(JavaThread* thread) {
77 serialize_thread_state_internal(thread, false);
78 }
79
80 private:
81 static void serialize_thread_state_internal(JavaThread* thread, bool needs_exception_handler) {
82 // Make sure new state is seen by VM thread
83 if (os::is_MP()) {
84 if (UseMembar) {
85 // Force a fence between the write above and read below
86 OrderAccess::fence();
87 } else {
88 // store to serialize page so VM thread can do pseudo remote membar
89 if (needs_exception_handler) {
90 os::write_memory_serialize_page_with_handler(thread);
91 } else {
92 os::write_memory_serialize_page(thread);
93 }
94 }
95 }
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 InterfaceSupport::serialize_thread_state(thread);
122
123 SafepointMechanism::block_if_requested(thread);
124 thread->set_thread_state(to);
125
126 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
127 }
128
129 // transition_and_fence must be used on any thread state transition
130 // where there might not be a Java call stub on the stack, in
131 // particular on Windows where the Structured Exception Handler is
132 // set up in the call stub. os::write_memory_serialize_page() can
133 // fault and we can't recover from it on Windows without a SEH in
134 // place.
135 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
136 assert(thread->thread_state() == from, "coming from wrong thread state");
137 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
138 // Change to transition state
139 thread->set_thread_state((JavaThreadState)(from + 1));
140
141 InterfaceSupport::serialize_thread_state_with_handler(thread);
142
143 SafepointMechanism::block_if_requested(thread);
144 thread->set_thread_state(to);
145
146 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
147 }
148
149 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we
150 // never block on entry to the VM. This will break the code, since e.g. preserve arguments
151 // have not been setup.
152 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {
153 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");
154 thread->set_thread_state(to);
155 }
156
157 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {
158 assert((to & 1) == 0, "odd numbers are transitions states");
159 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");
160 // Change to transition state
161 thread->set_thread_state(_thread_in_native_trans);
162
163 InterfaceSupport::serialize_thread_state_with_handler(thread);
164
165 // We never install asynchronous exceptions when coming (back) in
166 // to the runtime from native code because the runtime is not set
167 // up to handle exceptions floating around at arbitrary points.
168 if (SafepointMechanism::poll(thread) || thread->is_suspend_after_native()) {
169 JavaThread::check_safepoint_and_suspend_for_native_trans(thread);
170
171 // Clear unhandled oops anywhere where we could block, even if we don't.
172 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
173 }
174
175 thread->set_thread_state(to);
176 }
177 protected:
178 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); }
179 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); }
180 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); }
181 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); }
182 };
183
184 class ThreadInVMForHandshake : public ThreadStateTransition {
185 const JavaThreadState _original_state;
186
187 void transition_back() {
188 // This can be invoked from transition states and must return to the original state properly
189 assert(_thread->thread_state() == _thread_in_vm, "should only call when leaving VM after handshake");
190 _thread->set_thread_state(_thread_in_vm_trans);
191
192 InterfaceSupport::serialize_thread_state(_thread);
193
194 SafepointMechanism::block_if_requested(_thread);
195
196 _thread->set_thread_state(_original_state);
197 }
198
199 public:
200
201 ThreadInVMForHandshake(JavaThread* thread) : ThreadStateTransition(thread),
202 _original_state(thread->thread_state()) {
203
204 if (thread->has_last_Java_frame()) {
205 thread->frame_anchor()->make_walkable(thread);
206 }
207
208 thread->set_thread_state(_thread_in_vm);
209 }
210
211 ~ThreadInVMForHandshake() {
212 transition_back();
213 }
214
215 };
216
217 class ThreadInVMfromJava : public ThreadStateTransition {
218 public:
219 ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) {
220 trans_from_java(_thread_in_vm);
221 }
222 ~ThreadInVMfromJava() {
223 if (_thread->stack_yellow_reserved_zone_disabled()) {
224 _thread->enable_stack_yellow_reserved_zone();
225 }
226 trans(_thread_in_vm, _thread_in_Java);
227 // Check for pending. async. exceptions or suspends.
228 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition();
229 }
230 };
231
232
233 class ThreadInVMfromUnknown {
234 private:
235 JavaThread* _thread;
236 public:
237 ThreadInVMfromUnknown() : _thread(NULL) {
238 Thread* t = Thread::current();
239 if (t->is_Java_thread()) {
240 JavaThread* t2 = (JavaThread*) t;
241 if (t2->thread_state() == _thread_in_native) {
242 _thread = t2;
243 ThreadStateTransition::transition_from_native(t2, _thread_in_vm);
244 // Used to have a HandleMarkCleaner but that is dangerous as
245 // it could free a handle in our (indirect, nested) caller.
246 // We expect any handles will be short lived and figure we
247 // don't need an actual HandleMark.
248 }
249 }
250 }
251 ~ThreadInVMfromUnknown() {
252 if (_thread) {
253 ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native);
254 }
255 }
256 };
257
258
259 class ThreadInVMfromNative : public ThreadStateTransition {
260 public:
261 ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) {
262 trans_from_native(_thread_in_vm);
263 }
264 ~ThreadInVMfromNative() {
265 trans_and_fence(_thread_in_vm, _thread_in_native);
266 }
267 };
268
269
270 class ThreadToNativeFromVM : public ThreadStateTransition {
271 public:
272 ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {
273 // We are leaving the VM at this point and going directly to native code.
274 // Block, if we are in the middle of a safepoint synchronization.
275 assert(!thread->owns_locks(), "must release all locks when leaving VM");
276 thread->frame_anchor()->make_walkable(thread);
277 trans_and_fence(_thread_in_vm, _thread_in_native);
278 // Check for pending. async. exceptions or suspends.
279 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false);
280 }
281
282 ~ThreadToNativeFromVM() {
283 trans_from_native(_thread_in_vm);
284 assert(!_thread->is_pending_jni_exception_check(), "Pending JNI Exception Check");
285 // We don't need to clear_walkable because it will happen automagically when we return to java
286 }
287 };
288
289
290 class ThreadBlockInVM : public ThreadStateTransition {
291 public:
292 ThreadBlockInVM(JavaThread *thread)
293 : ThreadStateTransition(thread) {
294 // Once we are blocked vm expects stack to be walkable
295 thread->frame_anchor()->make_walkable(thread);
296 trans_and_fence(_thread_in_vm, _thread_blocked);
297 }
298 ~ThreadBlockInVM() {
299 trans_and_fence(_thread_blocked, _thread_in_vm);
300 // We don't need to clear_walkable because it will happen automagically when we return to java
301 }
302 };
303
304
305 // This special transition class is only used to prevent asynchronous exceptions
306 // from being installed on vm exit in situations where we can't tolerate them.
307 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705.
308 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition {
309 public:
310 ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) {
311 trans_from_java(_thread_in_vm);
312 }
313 ~ThreadInVMfromJavaNoAsyncException() {
314 if (_thread->stack_yellow_reserved_zone_disabled()) {
315 _thread->enable_stack_yellow_reserved_zone();
316 }
317 trans(_thread_in_vm, _thread_in_Java);
318 // NOTE: We do not check for pending. async. exceptions.
319 // If we did and moved the pending async exception over into the
320 // pending exception field, we would need to deopt (currently C2
321 // only). However, to do so would require that we transition back
322 // to the _thread_in_vm state. Instead we postpone the handling of
323 // the async exception.
324
325
326 // Check for pending. suspends only.
327 if (_thread->has_special_runtime_exit_condition())
328 _thread->handle_special_runtime_exit_condition(false);
329 }
330 };
331
332 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro.
333 // Can be used to verify properties on enter/exit of the VM.
334
335 #ifdef ASSERT
336 class VMEntryWrapper {
337 public:
338 VMEntryWrapper();
339 ~VMEntryWrapper();
340 };
341
342
343 class VMNativeEntryWrapper {
344 public:
345 VMNativeEntryWrapper() {
346 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
347 }
348
349 ~VMNativeEntryWrapper() {
350 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
351 }
352 };
353
354 #endif
355
356
357 // VM-internal runtime interface support
358
359 #ifdef ASSERT
360
361 class RuntimeHistogramElement : public HistogramElement {
362 public:
363 RuntimeHistogramElement(const char* name);
364 };
365
366 #define TRACE_CALL(result_type, header) \
367 InterfaceSupport::_number_of_calls++; \
368 if (CountRuntimeCalls) { \
369 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \
370 if (e != NULL) e->increment_count(); \
371 }
372 #else
373 #define TRACE_CALL(result_type, header) \
374 /* do nothing */
375 #endif
376
377
378 // LEAF routines do not lock, GC or throw exceptions
379
380 #define VM_LEAF_BASE(result_type, header) \
381 TRACE_CALL(result_type, header) \
382 debug_only(NoHandleMark __hm;) \
383 os::verify_stack_alignment(); \
384 /* begin of body */
385
386 #define VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) \
387 TRACE_CALL(result_type, header) \
388 debug_only(ResetNoHandleMark __rnhm;) \
389 HandleMarkCleaner __hm(thread); \
390 Thread* THREAD = thread; \
391 os::verify_stack_alignment(); \
392 /* begin of body */
393
394
395 // ENTRY routines may lock, GC and throw exceptions
396
397 #define VM_ENTRY_BASE(result_type, header, thread) \
398 TRACE_CALL(result_type, header) \
399 HandleMarkCleaner __hm(thread); \
400 Thread* THREAD = thread; \
401 os::verify_stack_alignment(); \
402 /* begin of body */
403
404
405 // QUICK_ENTRY routines behave like ENTRY but without a handle mark
406
407 #define VM_QUICK_ENTRY_BASE(result_type, header, thread) \
408 TRACE_CALL(result_type, header) \
409 debug_only(NoHandleMark __hm;) \
410 Thread* THREAD = thread; \
411 os::verify_stack_alignment(); \
412 /* begin of body */
413
414
415 // Definitions for IRT (Interpreter Runtime)
416 // (thread is an argument passed in to all these routines)
417
418 #define IRT_ENTRY(result_type, header) \
419 result_type header { \
420 ThreadInVMfromJava __tiv(thread); \
421 VM_ENTRY_BASE(result_type, header, thread) \
422 debug_only(VMEntryWrapper __vew;)
423
424
425 #define IRT_LEAF(result_type, header) \
426 result_type header { \
427 VM_LEAF_BASE(result_type, header) \
428 debug_only(NoSafepointVerifier __nspv(true);)
429
430
431 #define IRT_ENTRY_NO_ASYNC(result_type, header) \
432 result_type header { \
433 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
434 VM_ENTRY_BASE(result_type, header, thread) \
435 debug_only(VMEntryWrapper __vew;)
436
437 #define IRT_END }
438
439
440 // Definitions for JRT (Java (Compiler/Shared) Runtime)
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