1 /*
2 * Copyright (c) 1997, 2018, 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 "runtime/handles.inline.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "runtime/orderAccess.hpp"
31 #include "runtime/os.hpp"
32 #include "runtime/safepointMechanism.inline.hpp"
33 #include "runtime/safepointVerifiers.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 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 OrderAccess::fence();
83 }
84 };
85
86
87 // Basic class for all thread transition classes.
88
89 class ThreadStateTransition : public StackObj {
90 protected:
91 JavaThread* _thread;
92 public:
93 ThreadStateTransition(JavaThread *thread) {
94 _thread = thread;
95 assert(thread != NULL && thread->is_Java_thread(), "must be Java thread");
96 }
97
98 // Change threadstate in a manner, so safepoint can detect changes.
99 // Time-critical: called on exit from every runtime routine
100 static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
101 assert(from != _thread_in_Java, "use transition_from_java");
102 assert(from != _thread_in_native, "use transition_from_native");
103 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
104 assert(thread->thread_state() == from, "coming from wrong thread state");
105 // Change to transition state
106 thread->set_thread_state((JavaThreadState)(from + 1));
107
108 InterfaceSupport::serialize_thread_state(thread);
109
110 SafepointMechanism::block_if_requested(thread);
111 thread->set_thread_state(to);
112
113 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
114 }
115
116 // transition_and_fence must be used on any thread state transition
117 // where there might not be a Java call stub on the stack, in
118 // particular on Windows where the Structured Exception Handler is
119 // set up in the call stub.
120 static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
121 assert(thread->thread_state() == from, "coming from wrong thread state");
122 assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
123 // Change to transition state
124 thread->set_thread_state((JavaThreadState)(from + 1));
125
126 InterfaceSupport::serialize_thread_state_with_handler(thread);
127
128 SafepointMechanism::block_if_requested(thread);
129 thread->set_thread_state(to);
130
131 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
132 }
133
134 // Same as above, but assumes from = _thread_in_Java. This is simpler, since we
135 // never block on entry to the VM. This will break the code, since e.g. preserve arguments
136 // have not been setup.
137 static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {
138 assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");
139 thread->set_thread_state(to);
140 }
141
142 static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {
143 assert((to & 1) == 0, "odd numbers are transitions states");
144 assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");
145 // Change to transition state
146 thread->set_thread_state(_thread_in_native_trans);
147
148 InterfaceSupport::serialize_thread_state_with_handler(thread);
149
150 // We never install asynchronous exceptions when coming (back) in
151 // to the runtime from native code because the runtime is not set
152 // up to handle exceptions floating around at arbitrary points.
153 if (SafepointMechanism::should_block(thread) || thread->is_suspend_after_native()) {
154 JavaThread::check_safepoint_and_suspend_for_native_trans(thread);
155
156 // Clear unhandled oops anywhere where we could block, even if we don't.
157 CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
158 }
159
160 thread->set_thread_state(to);
161 }
162 protected:
163 void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); }
164 void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); }
165 void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); }
166 void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); }
167 };
168
169 class ThreadInVMForHandshake : public ThreadStateTransition {
170 const JavaThreadState _original_state;
171
172 void transition_back() {
173 // This can be invoked from transition states and must return to the original state properly
174 assert(_thread->thread_state() == _thread_in_vm, "should only call when leaving VM after handshake");
175 _thread->set_thread_state(_thread_in_vm_trans);
176
177 InterfaceSupport::serialize_thread_state(_thread);
178
179 SafepointMechanism::block_if_requested(_thread);
180
181 _thread->set_thread_state(_original_state);
182 }
183
184 public:
185
186 ThreadInVMForHandshake(JavaThread* thread) : ThreadStateTransition(thread),
187 _original_state(thread->thread_state()) {
188
189 if (thread->has_last_Java_frame()) {
190 thread->frame_anchor()->make_walkable(thread);
191 }
192
193 thread->set_thread_state(_thread_in_vm);
194 }
195
196 ~ThreadInVMForHandshake() {
197 transition_back();
198 }
199
200 };
201
202 class ThreadInVMfromJava : public ThreadStateTransition {
203 public:
204 ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) {
205 trans_from_java(_thread_in_vm);
206 }
207 ~ThreadInVMfromJava() {
208 if (_thread->stack_yellow_reserved_zone_disabled()) {
209 _thread->enable_stack_yellow_reserved_zone();
210 }
211 trans(_thread_in_vm, _thread_in_Java);
212 // Check for pending. async. exceptions or suspends.
213 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition();
214 }
215 };
216
217
218 class ThreadInVMfromUnknown {
219 private:
220 JavaThread* _thread;
221 public:
222 ThreadInVMfromUnknown() : _thread(NULL) {
223 Thread* t = Thread::current();
224 if (t->is_Java_thread()) {
225 JavaThread* t2 = (JavaThread*) t;
226 if (t2->thread_state() == _thread_in_native) {
227 _thread = t2;
228 ThreadStateTransition::transition_from_native(t2, _thread_in_vm);
229 // Used to have a HandleMarkCleaner but that is dangerous as
230 // it could free a handle in our (indirect, nested) caller.
231 // We expect any handles will be short lived and figure we
232 // don't need an actual HandleMark.
233 }
234 }
235 }
236 ~ThreadInVMfromUnknown() {
237 if (_thread) {
238 ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native);
239 }
240 }
241 };
242
243
244 class ThreadInVMfromNative : public ThreadStateTransition {
245 public:
246 ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) {
247 trans_from_native(_thread_in_vm);
248 }
249 ~ThreadInVMfromNative() {
250 trans_and_fence(_thread_in_vm, _thread_in_native);
251 }
252 };
253
254
255 class ThreadToNativeFromVM : public ThreadStateTransition {
256 public:
257 ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {
258 // We are leaving the VM at this point and going directly to native code.
259 // Block, if we are in the middle of a safepoint synchronization.
260 assert(!thread->owns_locks(), "must release all locks when leaving VM");
261 thread->frame_anchor()->make_walkable(thread);
262 trans_and_fence(_thread_in_vm, _thread_in_native);
263 // Check for pending. async. exceptions or suspends.
264 if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false);
265 }
266
267 ~ThreadToNativeFromVM() {
268 trans_from_native(_thread_in_vm);
269 assert(!_thread->is_pending_jni_exception_check(), "Pending JNI Exception Check");
270 // We don't need to clear_walkable because it will happen automagically when we return to java
271 }
272 };
273
274
275 class ThreadBlockInVM : public ThreadStateTransition {
276 public:
277 ThreadBlockInVM(JavaThread *thread)
278 : ThreadStateTransition(thread) {
279 // Once we are blocked vm expects stack to be walkable
280 thread->frame_anchor()->make_walkable(thread);
281 trans_and_fence(_thread_in_vm, _thread_blocked);
282 }
283 ~ThreadBlockInVM() {
284 trans_and_fence(_thread_blocked, _thread_in_vm);
285 // We don't need to clear_walkable because it will happen automagically when we return to java
286 }
287 };
288
289
290 // This special transition class is only used to prevent asynchronous exceptions
291 // from being installed on vm exit in situations where we can't tolerate them.
292 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705.
293 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition {
294 public:
295 ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) {
296 trans_from_java(_thread_in_vm);
297 }
298 ~ThreadInVMfromJavaNoAsyncException() {
299 if (_thread->stack_yellow_reserved_zone_disabled()) {
300 _thread->enable_stack_yellow_reserved_zone();
301 }
302 trans(_thread_in_vm, _thread_in_Java);
303 // NOTE: We do not check for pending. async. exceptions.
304 // If we did and moved the pending async exception over into the
305 // pending exception field, we would need to deopt (currently C2
306 // only). However, to do so would require that we transition back
307 // to the _thread_in_vm state. Instead we postpone the handling of
308 // the async exception.
309
310
311 // Check for pending. suspends only.
312 if (_thread->has_special_runtime_exit_condition())
313 _thread->handle_special_runtime_exit_condition(false);
314 }
315 };
316
317 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro.
318 // Can be used to verify properties on enter/exit of the VM.
319
320 #ifdef ASSERT
321 class VMEntryWrapper {
322 public:
323 VMEntryWrapper();
324 ~VMEntryWrapper();
325 };
326
327
328 class VMNativeEntryWrapper {
329 public:
330 VMNativeEntryWrapper() {
331 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
332 }
333
334 ~VMNativeEntryWrapper() {
335 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
336 }
337 };
338
339 #endif
340
341
342 // VM-internal runtime interface support
343
344 // Definitions for JRT (Java (Compiler/Shared) Runtime)
345
346 // JRT_LEAF currently can be called from either _thread_in_Java or
347 // _thread_in_native mode. In _thread_in_native, it is ok
348 // for another thread to trigger GC. The rest of the JRT_LEAF
349 // rules apply.
350 class JRTLeafVerifier : public NoSafepointVerifier {
351 static bool should_verify_GC();
352 public:
353 #ifdef ASSERT
354 JRTLeafVerifier();
355 ~JRTLeafVerifier();
356 #else
357 JRTLeafVerifier() {}
358 ~JRTLeafVerifier() {}
359 #endif
360 };
361
362 #ifdef ASSERT
363
364 class RuntimeHistogramElement : public HistogramElement {
365 public:
366 RuntimeHistogramElement(const char* name);
367 };
368
369 #define TRACE_CALL(result_type, header) \
370 InterfaceSupport::_number_of_calls++; \
371 if (CountRuntimeCalls) { \
372 static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \
373 if (e != NULL) e->increment_count(); \
374 }
375 #else
376 #define TRACE_CALL(result_type, header) \
377 /* do nothing */
378 #endif
379
380
381 // LEAF routines do not lock, GC or throw exceptions
382
383 #define VM_LEAF_BASE(result_type, header) \
384 TRACE_CALL(result_type, header) \
385 debug_only(NoHandleMark __hm;) \
386 os::verify_stack_alignment(); \
387 /* begin of body */
388
389 #define VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) \
390 TRACE_CALL(result_type, header) \
391 debug_only(ResetNoHandleMark __rnhm;) \
392 HandleMarkCleaner __hm(thread); \
393 Thread* THREAD = thread; \
394 os::verify_stack_alignment(); \
395 /* begin of body */
396
397
398 // ENTRY routines may lock, GC and throw exceptions
399
400 #define VM_ENTRY_BASE(result_type, header, thread) \
401 TRACE_CALL(result_type, header) \
402 HandleMarkCleaner __hm(thread); \
403 Thread* THREAD = thread; \
404 os::verify_stack_alignment(); \
405 /* begin of body */
406
407
408 // QUICK_ENTRY routines behave like ENTRY but without a handle mark
409
410 #define VM_QUICK_ENTRY_BASE(result_type, header, thread) \
411 TRACE_CALL(result_type, header) \
412 debug_only(NoHandleMark __hm;) \
413 Thread* THREAD = thread; \
414 os::verify_stack_alignment(); \
415 /* begin of body */
416
417
418 // Definitions for IRT (Interpreter Runtime)
419 // (thread is an argument passed in to all these routines)
420
421 #define IRT_ENTRY(result_type, header) \
422 result_type header { \
423 ThreadInVMfromJava __tiv(thread); \
424 VM_ENTRY_BASE(result_type, header, thread) \
425 debug_only(VMEntryWrapper __vew;)
426
427
428 #define IRT_LEAF(result_type, header) \
429 result_type header { \
430 VM_LEAF_BASE(result_type, header) \
431 debug_only(NoSafepointVerifier __nspv(true);)
432
433
434 #define IRT_ENTRY_NO_ASYNC(result_type, header) \
435 result_type header { \
436 ThreadInVMfromJavaNoAsyncException __tiv(thread); \
437 VM_ENTRY_BASE(result_type, header, thread) \
438 debug_only(VMEntryWrapper __vew;)
439
440 #define IRT_END }
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