/
interfaceSupport.inline.hpp
499 lines (409 loc) · 19.5 KB
/
interfaceSupport.inline.hpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
/*
* Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_RUNTIME_INTERFACESUPPORT_INLINE_HPP
#define SHARE_RUNTIME_INTERFACESUPPORT_INLINE_HPP
#include "runtime/handles.inline.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/orderAccess.hpp"
#include "runtime/os.hpp"
#include "runtime/safepointMechanism.inline.hpp"
#include "runtime/safepointVerifiers.hpp"
#include "runtime/thread.hpp"
#include "runtime/vmOperations.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/histogram.hpp"
#include "utilities/macros.hpp"
#include "utilities/preserveException.hpp"
// Wrapper for all entry points to the virtual machine.
// InterfaceSupport provides functionality used by the VM_LEAF_BASE and
// VM_ENTRY_BASE macros. These macros are used to guard entry points into
// the VM and perform checks upon leave of the VM.
class InterfaceSupport: AllStatic {
# ifdef ASSERT
public:
static unsigned int _scavenge_alot_counter;
static unsigned int _fullgc_alot_counter;
static int _fullgc_alot_invocation;
// Helper methods used to implement +ScavengeALot and +FullGCALot
static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); }
static void gc_alot();
static void walk_stack_from(vframe* start_vf);
static void walk_stack();
static void zombieAll();
static void deoptimizeAll();
static void verify_stack();
static void verify_last_frame();
# endif
};
// Basic class for all thread transition classes.
class ThreadStateTransition : public StackObj {
protected:
JavaThread* _thread;
public:
ThreadStateTransition(JavaThread *thread) {
_thread = thread;
assert(thread != NULL, "must be active Java thread");
}
// Change threadstate in a manner, so safepoint can detect changes.
// Time-critical: called on exit from every runtime routine
static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) {
assert(from != _thread_in_Java, "use transition_from_java");
assert(from != _thread_in_native, "use transition_from_native");
assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");
assert(thread->thread_state() == from, "coming from wrong thread state");
// Check NoSafepointVerifier
// This also clears unhandled oops if CheckUnhandledOops is used.
thread->check_possible_safepoint();
// Change to transition state and ensure it is seen by the VM thread.
thread->set_thread_state_fence((JavaThreadState)(from + 1));
SafepointMechanism::process_if_requested(thread);
thread->set_thread_state(to);
}
// Same as above, but assumes from = _thread_in_Java. This is simpler, since we
// never block on entry to the VM. This will break the code, since e.g. preserve arguments
// have not been setup.
static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {
assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");
thread->set_thread_state(to);
}
static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {
assert((to & 1) == 0, "odd numbers are transitions states");
assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");
// Change to transition state and ensure it is seen by the VM thread.
thread->set_thread_state_fence(_thread_in_native_trans);
// We never install asynchronous exceptions when coming (back) in
// to the runtime from native code because the runtime is not set
// up to handle exceptions floating around at arbitrary points.
if (SafepointMechanism::should_process(thread) || thread->is_suspend_after_native()) {
JavaThread::check_safepoint_and_suspend_for_native_trans(thread);
}
thread->set_thread_state(to);
}
protected:
void trans(JavaThreadState from, JavaThreadState to) { transition(_thread, from, to); }
void trans_from_java(JavaThreadState to) { transition_from_java(_thread, to); }
void trans_from_native(JavaThreadState to) { transition_from_native(_thread, to); }
};
class ThreadInVMForHandshake : public ThreadStateTransition {
const JavaThreadState _original_state;
public:
ThreadInVMForHandshake(JavaThread* thread) : ThreadStateTransition(thread),
_original_state(thread->thread_state()) {
if (thread->has_last_Java_frame()) {
thread->frame_anchor()->make_walkable(thread);
}
thread->set_thread_state(_thread_in_vm);
// Threads shouldn't block if they are in the middle of printing, but...
ttyLocker::break_tty_lock_for_safepoint(os::current_thread_id());
}
~ThreadInVMForHandshake() {
assert(_thread->thread_state() == _thread_in_vm, "should only call when leaving VM after handshake");
_thread->set_thread_state(_original_state);
}
};
class ThreadInVMfromJava : public ThreadStateTransition {
public:
ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) {
trans_from_java(_thread_in_vm);
}
~ThreadInVMfromJava() {
if (_thread->stack_overflow_state()->stack_yellow_reserved_zone_disabled()) {
_thread->stack_overflow_state()->enable_stack_yellow_reserved_zone();
}
trans(_thread_in_vm, _thread_in_Java);
// Check for pending. async. exceptions or suspends.
if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition();
}
};
class ThreadInVMfromUnknown {
JavaThread* _thread;
public:
ThreadInVMfromUnknown() : _thread(NULL) {
Thread* t = Thread::current();
if (t->is_Java_thread()) {
JavaThread* t2 = t->as_Java_thread();
if (t2->thread_state() == _thread_in_native) {
_thread = t2;
ThreadStateTransition::transition_from_native(t2, _thread_in_vm);
// Used to have a HandleMarkCleaner but that is dangerous as
// it could free a handle in our (indirect, nested) caller.
// We expect any handles will be short lived and figure we
// don't need an actual HandleMark.
}
}
}
~ThreadInVMfromUnknown() {
if (_thread) {
ThreadStateTransition::transition(_thread, _thread_in_vm, _thread_in_native);
}
}
};
class ThreadInVMfromNative : public ThreadStateTransition {
public:
ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) {
trans_from_native(_thread_in_vm);
}
~ThreadInVMfromNative() {
trans(_thread_in_vm, _thread_in_native);
}
};
class ThreadToNativeFromVM : public ThreadStateTransition {
public:
ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {
// We are leaving the VM at this point and going directly to native code.
// Block, if we are in the middle of a safepoint synchronization.
assert(!thread->owns_locks(), "must release all locks when leaving VM");
thread->frame_anchor()->make_walkable(thread);
trans(_thread_in_vm, _thread_in_native);
// Check for pending. async. exceptions or suspends.
if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false);
}
~ThreadToNativeFromVM() {
trans_from_native(_thread_in_vm);
assert(!_thread->is_pending_jni_exception_check(), "Pending JNI Exception Check");
// We don't need to clear_walkable because it will happen automagically when we return to java
}
};
class ThreadBlockInVM : public ThreadStateTransition {
public:
ThreadBlockInVM(JavaThread *thread)
: ThreadStateTransition(thread) {
// Once we are blocked vm expects stack to be walkable
thread->frame_anchor()->make_walkable(thread);
trans(_thread_in_vm, _thread_blocked);
}
~ThreadBlockInVM() {
trans(_thread_blocked, _thread_in_vm);
OrderAccess::cross_modify_fence();
// We don't need to clear_walkable because it will happen automagically when we return to java
}
};
// Unlike ThreadBlockInVM, this class is designed to avoid certain deadlock scenarios while making
// transitions inside class Mutex in cases where we need to block for a safepoint or handshake. It
// receives an extra argument compared to ThreadBlockInVM, the address of a pointer to the mutex we
// are trying to acquire. This will be used to access and release the mutex if needed to avoid
// said deadlocks.
// It works like ThreadBlockInVM but differs from it in two ways:
// - When transitioning in (constructor), it checks for safepoints without blocking, i.e., calls
// back if needed to allow a pending safepoint to continue but does not block in it.
// - When transitioning back (destructor), if there is a pending safepoint or handshake it releases
// the mutex that is only partially acquired.
class ThreadBlockInVMWithDeadlockCheck : public ThreadStateTransition {
private:
Mutex** _in_flight_mutex_addr;
void release_mutex() {
assert(_in_flight_mutex_addr != NULL, "_in_flight_mutex_addr should have been set on constructor");
Mutex* in_flight_mutex = *_in_flight_mutex_addr;
if (in_flight_mutex != NULL) {
in_flight_mutex->release_for_safepoint();
*_in_flight_mutex_addr = NULL;
}
}
public:
ThreadBlockInVMWithDeadlockCheck(JavaThread* thread, Mutex** in_flight_mutex_addr)
: ThreadStateTransition(thread), _in_flight_mutex_addr(in_flight_mutex_addr) {
// Once we are blocked vm expects stack to be walkable
thread->frame_anchor()->make_walkable(thread);
// All unsafe states are treated the same by the VMThread
// so we can skip the _thread_in_vm_trans state here. Since
// we don't read poll, it's enough to order the stores.
OrderAccess::storestore();
thread->set_thread_state(_thread_blocked);
}
~ThreadBlockInVMWithDeadlockCheck() {
// Change to transition state and ensure it is seen by the VM thread.
_thread->set_thread_state_fence((JavaThreadState)(_thread_blocked_trans));
if (SafepointMechanism::should_process(_thread)) {
release_mutex();
SafepointMechanism::process_if_requested(_thread);
}
_thread->set_thread_state(_thread_in_vm);
OrderAccess::cross_modify_fence();
}
};
// This special transition class is only used to prevent asynchronous exceptions
// from being installed on vm exit in situations where we can't tolerate them.
// See bugs: 4324348, 4854693, 4998314, 5040492, 5050705.
class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition {
public:
ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) {
trans_from_java(_thread_in_vm);
}
~ThreadInVMfromJavaNoAsyncException() {
if (_thread->stack_overflow_state()->stack_yellow_reserved_zone_disabled()) {
_thread->stack_overflow_state()->enable_stack_yellow_reserved_zone();
}
trans(_thread_in_vm, _thread_in_Java);
// NOTE: We do not check for pending. async. exceptions.
// If we did and moved the pending async exception over into the
// pending exception field, we would need to deopt (currently C2
// only). However, to do so would require that we transition back
// to the _thread_in_vm state. Instead we postpone the handling of
// the async exception.
// Check for pending. suspends only.
if (_thread->has_special_runtime_exit_condition())
_thread->handle_special_runtime_exit_condition(false);
}
};
// Debug class instantiated in JRT_ENTRY macro.
// Can be used to verify properties on enter/exit of the VM.
#ifdef ASSERT
class VMEntryWrapper {
public:
VMEntryWrapper();
~VMEntryWrapper();
};
class VMNativeEntryWrapper {
public:
VMNativeEntryWrapper();
~VMNativeEntryWrapper();
};
class RuntimeHistogramElement : public HistogramElement {
public:
RuntimeHistogramElement(const char* name);
};
#endif // ASSERT
#ifdef ASSERT
#define TRACE_CALL(result_type, header) \
if (CountRuntimeCalls) { \
static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \
if (e != NULL) e->increment_count(); \
}
#else
#define TRACE_CALL(result_type, header) \
/* do nothing */
#endif // ASSERT
// LEAF routines do not lock, GC or throw exceptions
#define VM_LEAF_BASE(result_type, header) \
TRACE_CALL(result_type, header) \
debug_only(NoHandleMark __hm;) \
os::verify_stack_alignment(); \
/* begin of body */
#define VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread) \
TRACE_CALL(result_type, header) \
debug_only(ResetNoHandleMark __rnhm;) \
HandleMarkCleaner __hm(thread); \
Thread* THREAD = thread; \
os::verify_stack_alignment(); \
/* begin of body */
// ENTRY routines may lock, GC and throw exceptions
#define VM_ENTRY_BASE(result_type, header, thread) \
TRACE_CALL(result_type, header) \
HandleMarkCleaner __hm(thread); \
Thread* THREAD = thread; \
os::verify_stack_alignment(); \
/* begin of body */
#define JRT_ENTRY(result_type, header) \
result_type header { \
ThreadInVMfromJava __tiv(thread); \
VM_ENTRY_BASE(result_type, header, thread) \
debug_only(VMEntryWrapper __vew;)
// JRT_LEAF currently can be called from either _thread_in_Java or
// _thread_in_native mode.
//
// JRT_LEAF rules:
// A JRT_LEAF method may not interfere with safepointing by
// 1) acquiring or blocking on a Mutex or JavaLock - checked
// 2) allocating heap memory - checked
// 3) executing a VM operation - checked
// 4) executing a system call (including malloc) that could block or grab a lock
// 5) invoking GC
// 6) reaching a safepoint
// 7) running too long
// Nor may any method it calls.
#define JRT_LEAF(result_type, header) \
result_type header { \
VM_LEAF_BASE(result_type, header) \
debug_only(NoSafepointVerifier __nsv;)
#define JRT_ENTRY_NO_ASYNC(result_type, header) \
result_type header { \
ThreadInVMfromJavaNoAsyncException __tiv(thread); \
VM_ENTRY_BASE(result_type, header, thread) \
debug_only(VMEntryWrapper __vew;)
// Same as JRT Entry but allows for return value after the safepoint
// to get back into Java from the VM
#define JRT_BLOCK_ENTRY(result_type, header) \
result_type header { \
TRACE_CALL(result_type, header) \
HandleMarkCleaner __hm(thread);
#define JRT_BLOCK \
{ \
ThreadInVMfromJava __tiv(thread); \
Thread* THREAD = thread; \
debug_only(VMEntryWrapper __vew;)
#define JRT_BLOCK_NO_ASYNC \
{ \
ThreadInVMfromJavaNoAsyncException __tiv(thread); \
Thread* THREAD = thread; \
debug_only(VMEntryWrapper __vew;)
#define JRT_BLOCK_END }
#define JRT_END }
// Definitions for JNI
#define JNI_ENTRY(result_type, header) \
JNI_ENTRY_NO_PRESERVE(result_type, header) \
WeakPreserveExceptionMark __wem(thread);
#define JNI_ENTRY_NO_PRESERVE(result_type, header) \
extern "C" { \
result_type JNICALL header { \
JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
ThreadInVMfromNative __tiv(thread); \
debug_only(VMNativeEntryWrapper __vew;) \
VM_ENTRY_BASE(result_type, header, thread)
#define JNI_LEAF(result_type, header) \
extern "C" { \
result_type JNICALL header { \
JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \
VM_LEAF_BASE(result_type, header)
// Close the routine and the extern "C"
#define JNI_END } }
// Definitions for JVM
#define JVM_ENTRY(result_type, header) \
extern "C" { \
result_type JNICALL header { \
JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
ThreadInVMfromNative __tiv(thread); \
debug_only(VMNativeEntryWrapper __vew;) \
VM_ENTRY_BASE(result_type, header, thread)
#define JVM_ENTRY_NO_ENV(result_type, header) \
extern "C" { \
result_type JNICALL header { \
JavaThread* thread = JavaThread::current(); \
ThreadInVMfromNative __tiv(thread); \
debug_only(VMNativeEntryWrapper __vew;) \
VM_ENTRY_BASE(result_type, header, thread)
#define JVM_LEAF(result_type, header) \
extern "C" { \
result_type JNICALL header { \
VM_Exit::block_if_vm_exited(); \
VM_LEAF_BASE(result_type, header)
#define JVM_ENTRY_FROM_LEAF(env, result_type, header) \
{ { \
JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
ThreadInVMfromNative __tiv(thread); \
debug_only(VMNativeEntryWrapper __vew;) \
VM_ENTRY_BASE_FROM_LEAF(result_type, header, thread)
#define JVM_END } }
#endif // SHARE_RUNTIME_INTERFACESUPPORT_INLINE_HPP