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
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
|
// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Platform specific code for FreeBSD goes here. For the POSIX comaptible parts
// the implementation is in platform-posix.cc.
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/ucontext.h>
#include <stdlib.h>
#include <sys/types.h> // mmap & munmap
#include <sys/mman.h> // mmap & munmap
#include <sys/stat.h> // open
#include <sys/fcntl.h> // open
#include <unistd.h> // getpagesize
// If you don't have execinfo.h then you need devel/libexecinfo from ports.
#include <execinfo.h> // backtrace, backtrace_symbols
#include <strings.h> // index
#include <errno.h>
#include <stdarg.h>
#include <limits.h>
#undef MAP_TYPE
#include "v8.h"
#include "v8threads.h"
#include "platform.h"
#include "vm-state-inl.h"
namespace v8 {
namespace internal {
// 0 is never a valid thread id on FreeBSD since tids and pids share a
// name space and pid 0 is used to kill the group (see man 2 kill).
static const pthread_t kNoThread = (pthread_t) 0;
double ceiling(double x) {
// Correct as on OS X
if (-1.0 < x && x < 0.0) {
return -0.0;
} else {
return ceil(x);
}
}
static Mutex* limit_mutex = NULL;
void OS::SetUp() {
// Seed the random number generator.
// Convert the current time to a 64-bit integer first, before converting it
// to an unsigned. Going directly can cause an overflow and the seed to be
// set to all ones. The seed will be identical for different instances that
// call this setup code within the same millisecond.
uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
srandom(static_cast<unsigned int>(seed));
limit_mutex = CreateMutex();
}
void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
__asm__ __volatile__("" : : : "memory");
*ptr = value;
}
uint64_t OS::CpuFeaturesImpliedByPlatform() {
return 0; // FreeBSD runs on anything.
}
int OS::ActivationFrameAlignment() {
// 16 byte alignment on FreeBSD
return 16;
}
const char* OS::LocalTimezone(double time) {
if (isnan(time)) return "";
time_t tv = static_cast<time_t>(floor(time/msPerSecond));
struct tm* t = localtime(&tv);
if (NULL == t) return "";
return t->tm_zone;
}
double OS::LocalTimeOffset() {
time_t tv = time(NULL);
struct tm* t = localtime(&tv);
// tm_gmtoff includes any daylight savings offset, so subtract it.
return static_cast<double>(t->tm_gmtoff * msPerSecond -
(t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
}
// We keep the lowest and highest addresses mapped as a quick way of
// determining that pointers are outside the heap (used mostly in assertions
// and verification). The estimate is conservative, i.e., not all addresses in
// 'allocated' space are actually allocated to our heap. The range is
// [lowest, highest), inclusive on the low and and exclusive on the high end.
static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
static void* highest_ever_allocated = reinterpret_cast<void*>(0);
static void UpdateAllocatedSpaceLimits(void* address, int size) {
ASSERT(limit_mutex != NULL);
ScopedLock lock(limit_mutex);
lowest_ever_allocated = Min(lowest_ever_allocated, address);
highest_ever_allocated =
Max(highest_ever_allocated,
reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
}
bool OS::IsOutsideAllocatedSpace(void* address) {
return address < lowest_ever_allocated || address >= highest_ever_allocated;
}
size_t OS::AllocateAlignment() {
return getpagesize();
}
void* OS::Allocate(const size_t requested,
size_t* allocated,
bool executable) {
const size_t msize = RoundUp(requested, getpagesize());
int prot = PROT_READ | PROT_WRITE | (executable ? PROT_EXEC : 0);
void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANON, -1, 0);
if (mbase == MAP_FAILED) {
LOG(ISOLATE, StringEvent("OS::Allocate", "mmap failed"));
return NULL;
}
*allocated = msize;
UpdateAllocatedSpaceLimits(mbase, msize);
return mbase;
}
void OS::Free(void* buf, const size_t length) {
// TODO(1240712): munmap has a return value which is ignored here.
int result = munmap(buf, length);
USE(result);
ASSERT(result == 0);
}
void OS::Sleep(int milliseconds) {
unsigned int ms = static_cast<unsigned int>(milliseconds);
usleep(1000 * ms);
}
void OS::Abort() {
// Redirect to std abort to signal abnormal program termination.
abort();
}
void OS::DebugBreak() {
#if (defined(__arm__) || defined(__thumb__))
# if defined(CAN_USE_ARMV5_INSTRUCTIONS)
asm("bkpt 0");
# endif
#else
asm("int $3");
#endif
}
class PosixMemoryMappedFile : public OS::MemoryMappedFile {
public:
PosixMemoryMappedFile(FILE* file, void* memory, int size)
: file_(file), memory_(memory), size_(size) { }
virtual ~PosixMemoryMappedFile();
virtual void* memory() { return memory_; }
virtual int size() { return size_; }
private:
FILE* file_;
void* memory_;
int size_;
};
OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) {
FILE* file = fopen(name, "r+");
if (file == NULL) return NULL;
fseek(file, 0, SEEK_END);
int size = ftell(file);
void* memory =
mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
return new PosixMemoryMappedFile(file, memory, size);
}
OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
void* initial) {
FILE* file = fopen(name, "w+");
if (file == NULL) return NULL;
int result = fwrite(initial, size, 1, file);
if (result < 1) {
fclose(file);
return NULL;
}
void* memory =
mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
return new PosixMemoryMappedFile(file, memory, size);
}
PosixMemoryMappedFile::~PosixMemoryMappedFile() {
if (memory_) munmap(memory_, size_);
fclose(file_);
}
static unsigned StringToLong(char* buffer) {
return static_cast<unsigned>(strtol(buffer, NULL, 16)); // NOLINT
}
void OS::LogSharedLibraryAddresses() {
static const int MAP_LENGTH = 1024;
int fd = open("/proc/self/maps", O_RDONLY);
if (fd < 0) return;
while (true) {
char addr_buffer[11];
addr_buffer[0] = '0';
addr_buffer[1] = 'x';
addr_buffer[10] = 0;
int result = read(fd, addr_buffer + 2, 8);
if (result < 8) break;
unsigned start = StringToLong(addr_buffer);
result = read(fd, addr_buffer + 2, 1);
if (result < 1) break;
if (addr_buffer[2] != '-') break;
result = read(fd, addr_buffer + 2, 8);
if (result < 8) break;
unsigned end = StringToLong(addr_buffer);
char buffer[MAP_LENGTH];
int bytes_read = -1;
do {
bytes_read++;
if (bytes_read >= MAP_LENGTH - 1)
break;
result = read(fd, buffer + bytes_read, 1);
if (result < 1) break;
} while (buffer[bytes_read] != '\n');
buffer[bytes_read] = 0;
// Ignore mappings that are not executable.
if (buffer[3] != 'x') continue;
char* start_of_path = index(buffer, '/');
// There may be no filename in this line. Skip to next.
if (start_of_path == NULL) continue;
buffer[bytes_read] = 0;
LOG(i::Isolate::Current(), SharedLibraryEvent(start_of_path, start, end));
}
close(fd);
}
void OS::SignalCodeMovingGC() {
}
int OS::StackWalk(Vector<OS::StackFrame> frames) {
int frames_size = frames.length();
ScopedVector<void*> addresses(frames_size);
int frames_count = backtrace(addresses.start(), frames_size);
char** symbols = backtrace_symbols(addresses.start(), frames_count);
if (symbols == NULL) {
return kStackWalkError;
}
for (int i = 0; i < frames_count; i++) {
frames[i].address = addresses[i];
// Format a text representation of the frame based on the information
// available.
SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen),
"%s",
symbols[i]);
// Make sure line termination is in place.
frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
}
free(symbols);
return frames_count;
}
// Constants used for mmap.
static const int kMmapFd = -1;
static const int kMmapFdOffset = 0;
VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
VirtualMemory::VirtualMemory(size_t size) {
address_ = ReserveRegion(size);
size_ = size;
}
VirtualMemory::VirtualMemory(size_t size, size_t alignment)
: address_(NULL), size_(0) {
ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
size_t request_size = RoundUp(size + alignment,
static_cast<intptr_t>(OS::AllocateAlignment()));
void* reservation = mmap(OS::GetRandomMmapAddr(),
request_size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
kMmapFd,
kMmapFdOffset);
if (reservation == MAP_FAILED) return;
Address base = static_cast<Address>(reservation);
Address aligned_base = RoundUp(base, alignment);
ASSERT_LE(base, aligned_base);
// Unmap extra memory reserved before and after the desired block.
if (aligned_base != base) {
size_t prefix_size = static_cast<size_t>(aligned_base - base);
OS::Free(base, prefix_size);
request_size -= prefix_size;
}
size_t aligned_size = RoundUp(size, OS::AllocateAlignment());
ASSERT_LE(aligned_size, request_size);
if (aligned_size != request_size) {
size_t suffix_size = request_size - aligned_size;
OS::Free(aligned_base + aligned_size, suffix_size);
request_size -= suffix_size;
}
ASSERT(aligned_size == request_size);
address_ = static_cast<void*>(aligned_base);
size_ = aligned_size;
}
VirtualMemory::~VirtualMemory() {
if (IsReserved()) {
bool result = ReleaseRegion(address(), size());
ASSERT(result);
USE(result);
}
}
bool VirtualMemory::IsReserved() {
return address_ != NULL;
}
void VirtualMemory::Reset() {
address_ = NULL;
size_ = 0;
}
bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
return CommitRegion(address, size, is_executable);
}
bool VirtualMemory::Uncommit(void* address, size_t size) {
return UncommitRegion(address, size);
}
void* VirtualMemory::ReserveRegion(size_t size) {
void* result = mmap(OS::GetRandomMmapAddr(),
size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
kMmapFd,
kMmapFdOffset);
if (result == MAP_FAILED) return NULL;
return result;
}
bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
if (MAP_FAILED == mmap(base,
size,
prot,
MAP_PRIVATE | MAP_ANON | MAP_FIXED,
kMmapFd,
kMmapFdOffset)) {
return false;
}
UpdateAllocatedSpaceLimits(base, size);
return true;
}
bool VirtualMemory::UncommitRegion(void* base, size_t size) {
return mmap(base,
size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED,
kMmapFd,
kMmapFdOffset) != MAP_FAILED;
}
bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
return munmap(base, size) == 0;
}
class Thread::PlatformData : public Malloced {
public:
pthread_t thread_; // Thread handle for pthread.
};
Thread::Thread(const Options& options)
: data_(new PlatformData),
stack_size_(options.stack_size()) {
set_name(options.name());
}
Thread::~Thread() {
delete data_;
}
static void* ThreadEntry(void* arg) {
Thread* thread = reinterpret_cast<Thread*>(arg);
// This is also initialized by the first argument to pthread_create() but we
// don't know which thread will run first (the original thread or the new
// one) so we initialize it here too.
thread->data()->thread_ = pthread_self();
ASSERT(thread->data()->thread_ != kNoThread);
thread->Run();
return NULL;
}
void Thread::set_name(const char* name) {
strncpy(name_, name, sizeof(name_));
name_[sizeof(name_) - 1] = '\0';
}
void Thread::Start() {
pthread_attr_t* attr_ptr = NULL;
pthread_attr_t attr;
if (stack_size_ > 0) {
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_));
attr_ptr = &attr;
}
pthread_create(&data_->thread_, attr_ptr, ThreadEntry, this);
ASSERT(data_->thread_ != kNoThread);
}
void Thread::Join() {
pthread_join(data_->thread_, NULL);
}
Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
pthread_key_t key;
int result = pthread_key_create(&key, NULL);
USE(result);
ASSERT(result == 0);
return static_cast<LocalStorageKey>(key);
}
void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
int result = pthread_key_delete(pthread_key);
USE(result);
ASSERT(result == 0);
}
void* Thread::GetThreadLocal(LocalStorageKey key) {
pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
return pthread_getspecific(pthread_key);
}
void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
pthread_setspecific(pthread_key, value);
}
void Thread::YieldCPU() {
sched_yield();
}
class FreeBSDMutex : public Mutex {
public:
FreeBSDMutex() {
pthread_mutexattr_t attrs;
int result = pthread_mutexattr_init(&attrs);
ASSERT(result == 0);
result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
ASSERT(result == 0);
result = pthread_mutex_init(&mutex_, &attrs);
ASSERT(result == 0);
}
virtual ~FreeBSDMutex() { pthread_mutex_destroy(&mutex_); }
virtual int Lock() {
int result = pthread_mutex_lock(&mutex_);
return result;
}
virtual int Unlock() {
int result = pthread_mutex_unlock(&mutex_);
return result;
}
virtual bool TryLock() {
int result = pthread_mutex_trylock(&mutex_);
// Return false if the lock is busy and locking failed.
if (result == EBUSY) {
return false;
}
ASSERT(result == 0); // Verify no other errors.
return true;
}
private:
pthread_mutex_t mutex_; // Pthread mutex for POSIX platforms.
};
Mutex* OS::CreateMutex() {
return new FreeBSDMutex();
}
class FreeBSDSemaphore : public Semaphore {
public:
explicit FreeBSDSemaphore(int count) { sem_init(&sem_, 0, count); }
virtual ~FreeBSDSemaphore() { sem_destroy(&sem_); }
virtual void Wait();
virtual bool Wait(int timeout);
virtual void Signal() { sem_post(&sem_); }
private:
sem_t sem_;
};
void FreeBSDSemaphore::Wait() {
while (true) {
int result = sem_wait(&sem_);
if (result == 0) return; // Successfully got semaphore.
CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup.
}
}
bool FreeBSDSemaphore::Wait(int timeout) {
const long kOneSecondMicros = 1000000; // NOLINT
// Split timeout into second and nanosecond parts.
struct timeval delta;
delta.tv_usec = timeout % kOneSecondMicros;
delta.tv_sec = timeout / kOneSecondMicros;
struct timeval current_time;
// Get the current time.
if (gettimeofday(¤t_time, NULL) == -1) {
return false;
}
// Calculate time for end of timeout.
struct timeval end_time;
timeradd(¤t_time, &delta, &end_time);
struct timespec ts;
TIMEVAL_TO_TIMESPEC(&end_time, &ts);
while (true) {
int result = sem_timedwait(&sem_, &ts);
if (result == 0) return true; // Successfully got semaphore.
if (result == -1 && errno == ETIMEDOUT) return false; // Timeout.
CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup.
}
}
Semaphore* OS::CreateSemaphore(int count) {
return new FreeBSDSemaphore(count);
}
static pthread_t GetThreadID() {
pthread_t thread_id = pthread_self();
return thread_id;
}
class Sampler::PlatformData : public Malloced {
public:
PlatformData() : vm_tid_(GetThreadID()) {}
pthread_t vm_tid() const { return vm_tid_; }
private:
pthread_t vm_tid_;
};
static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
USE(info);
if (signal != SIGPROF) return;
Isolate* isolate = Isolate::UncheckedCurrent();
if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) {
// We require a fully initialized and entered isolate.
return;
}
if (v8::Locker::IsActive() &&
!isolate->thread_manager()->IsLockedByCurrentThread()) {
return;
}
Sampler* sampler = isolate->logger()->sampler();
if (sampler == NULL || !sampler->IsActive()) return;
TickSample sample_obj;
TickSample* sample = CpuProfiler::TickSampleEvent(isolate);
if (sample == NULL) sample = &sample_obj;
// Extracting the sample from the context is extremely machine dependent.
ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
mcontext_t& mcontext = ucontext->uc_mcontext;
sample->state = isolate->current_vm_state();
#if V8_HOST_ARCH_IA32
sample->pc = reinterpret_cast<Address>(mcontext.mc_eip);
sample->sp = reinterpret_cast<Address>(mcontext.mc_esp);
sample->fp = reinterpret_cast<Address>(mcontext.mc_ebp);
#elif V8_HOST_ARCH_X64
sample->pc = reinterpret_cast<Address>(mcontext.mc_rip);
sample->sp = reinterpret_cast<Address>(mcontext.mc_rsp);
sample->fp = reinterpret_cast<Address>(mcontext.mc_rbp);
#elif V8_HOST_ARCH_ARM
sample->pc = reinterpret_cast<Address>(mcontext.mc_r15);
sample->sp = reinterpret_cast<Address>(mcontext.mc_r13);
sample->fp = reinterpret_cast<Address>(mcontext.mc_r11);
#endif
sampler->SampleStack(sample);
sampler->Tick(sample);
}
class SignalSender : public Thread {
public:
enum SleepInterval {
HALF_INTERVAL,
FULL_INTERVAL
};
static const int kSignalSenderStackSize = 32 * KB;
explicit SignalSender(int interval)
: Thread(Thread::Options("SignalSender", kSignalSenderStackSize)),
interval_(interval) {}
static void AddActiveSampler(Sampler* sampler) {
ScopedLock lock(mutex_);
SamplerRegistry::AddActiveSampler(sampler);
if (instance_ == NULL) {
// Install a signal handler.
struct sigaction sa;
sa.sa_sigaction = ProfilerSignalHandler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART | SA_SIGINFO;
signal_handler_installed_ =
(sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
// Start a thread that sends SIGPROF signal to VM threads.
instance_ = new SignalSender(sampler->interval());
instance_->Start();
} else {
ASSERT(instance_->interval_ == sampler->interval());
}
}
static void RemoveActiveSampler(Sampler* sampler) {
ScopedLock lock(mutex_);
SamplerRegistry::RemoveActiveSampler(sampler);
if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
delete instance_;
instance_ = NULL;
// Restore the old signal handler.
if (signal_handler_installed_) {
sigaction(SIGPROF, &old_signal_handler_, 0);
signal_handler_installed_ = false;
}
}
}
// Implement Thread::Run().
virtual void Run() {
SamplerRegistry::State state;
while ((state = SamplerRegistry::GetState()) !=
SamplerRegistry::HAS_NO_SAMPLERS) {
bool cpu_profiling_enabled =
(state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS);
bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled();
// When CPU profiling is enabled both JavaScript and C++ code is
// profiled. We must not suspend.
if (!cpu_profiling_enabled) {
if (rate_limiter_.SuspendIfNecessary()) continue;
}
if (cpu_profiling_enabled && runtime_profiler_enabled) {
if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
return;
}
Sleep(HALF_INTERVAL);
if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
return;
}
Sleep(HALF_INTERVAL);
} else {
if (cpu_profiling_enabled) {
if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile,
this)) {
return;
}
}
if (runtime_profiler_enabled) {
if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile,
NULL)) {
return;
}
}
Sleep(FULL_INTERVAL);
}
}
}
static void DoCpuProfile(Sampler* sampler, void* raw_sender) {
if (!sampler->IsProfiling()) return;
SignalSender* sender = reinterpret_cast<SignalSender*>(raw_sender);
sender->SendProfilingSignal(sampler->platform_data()->vm_tid());
}
static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
if (!sampler->isolate()->IsInitialized()) return;
sampler->isolate()->runtime_profiler()->NotifyTick();
}
void SendProfilingSignal(pthread_t tid) {
if (!signal_handler_installed_) return;
pthread_kill(tid, SIGPROF);
}
void Sleep(SleepInterval full_or_half) {
// Convert ms to us and subtract 100 us to compensate delays
// occuring during signal delivery.
useconds_t interval = interval_ * 1000 - 100;
if (full_or_half == HALF_INTERVAL) interval /= 2;
int result = usleep(interval);
#ifdef DEBUG
if (result != 0 && errno != EINTR) {
fprintf(stderr,
"SignalSender usleep error; interval = %u, errno = %d\n",
interval,
errno);
ASSERT(result == 0 || errno == EINTR);
}
#endif
USE(result);
}
const int interval_;
RuntimeProfilerRateLimiter rate_limiter_;
// Protects the process wide state below.
static Mutex* mutex_;
static SignalSender* instance_;
static bool signal_handler_installed_;
static struct sigaction old_signal_handler_;
private:
DISALLOW_COPY_AND_ASSIGN(SignalSender);
};
Mutex* SignalSender::mutex_ = OS::CreateMutex();
SignalSender* SignalSender::instance_ = NULL;
struct sigaction SignalSender::old_signal_handler_;
bool SignalSender::signal_handler_installed_ = false;
Sampler::Sampler(Isolate* isolate, int interval)
: isolate_(isolate),
interval_(interval),
profiling_(false),
active_(false),
samples_taken_(0) {
data_ = new PlatformData;
}
Sampler::~Sampler() {
ASSERT(!IsActive());
delete data_;
}
void Sampler::Start() {
ASSERT(!IsActive());
SetActive(true);
SignalSender::AddActiveSampler(this);
}
void Sampler::Stop() {
ASSERT(IsActive());
SignalSender::RemoveActiveSampler(this);
SetActive(false);
}
} } // namespace v8::internal
|