// Copyright 2006-2008 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 MacOS goes here. For the POSIX comaptible parts
// the implementation is in platform-posix.cc.
#include <dlfcn.h>
#include <unistd.h>
#include <sys/mman.h>
#include <mach/mach_init.h>
#include <mach-o/dyld.h>
#include <mach-o/getsect.h>
#include <AvailabilityMacros.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <libkern/OSAtomic.h>
#include <mach/mach.h>
#include <mach/semaphore.h>
#include <mach/task.h>
#include <mach/vm_statistics.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#undef MAP_TYPE
#include "v8.h"
#include "platform.h"
#include "vm-state-inl.h"
// Manually define these here as weak imports, rather than including execinfo.h.
// This lets us launch on 10.4 which does not have these calls.
extern "C" {
extern int backtrace(void**, int) __attribute__((weak_import));
extern char** backtrace_symbols(void* const*, int)
__attribute__((weak_import));
extern void backtrace_symbols_fd(void* const*, int, int)
__attribute__((weak_import));
}
namespace v8 {
namespace internal {
// 0 is never a valid thread id on MacOSX since a ptread_t is
// a pointer.
static const pthread_t kNoThread = (pthread_t) 0;
double ceiling(double x) {
// Correct Mac OS X Leopard 'ceil' behavior.
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 will 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();
}
// 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, ie, 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();
}
// Constants used for mmap.
// kMmapFd is used to pass vm_alloc flags to tag the region with the user
// defined tag 255 This helps identify V8-allocated regions in memory analysis
// tools like vmmap(1).
static const int kMmapFd = VM_MAKE_TAG(255);
static const off_t kMmapFdOffset = 0;
void* OS::Allocate(const size_t requested,
size_t* allocated,
bool is_executable) {
const size_t msize = RoundUp(requested, getpagesize());
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
void* mbase = mmap(NULL, msize, prot,
MAP_PRIVATE | MAP_ANON,
kMmapFd, kMmapFdOffset);
if (mbase == MAP_FAILED) {
LOG(Isolate::Current(), StringEvent("OS::Allocate", "mmap failed"));
return NULL;
}
*allocated = msize;
UpdateAllocatedSpaceLimits(mbase, msize);
return mbase;
}
void OS::Free(void* address, const size_t size) {
// TODO(1240712): munmap has a return value which is ignored here.
int result = munmap(address, size);
USE(result);
ASSERT(result == 0);
}
#ifdef ENABLE_HEAP_PROTECTION
void OS::Protect(void* address, size_t size) {
UNIMPLEMENTED();
}
void OS::Unprotect(void* address, size_t size, bool is_executable) {
UNIMPLEMENTED();
}
#endif
void OS::Sleep(int milliseconds) {
usleep(1000 * milliseconds);
}
void OS::Abort() {
// Redirect to std abort to signal abnormal program termination
abort();
}
void OS::DebugBreak() {
asm("int $3");
}
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_);
}
void OS::LogSharedLibraryAddresses() {
#ifdef ENABLE_LOGGING_AND_PROFILING
unsigned int images_count = _dyld_image_count();
for (unsigned int i = 0; i < images_count; ++i) {
const mach_header* header = _dyld_get_image_header(i);
if (header == NULL) continue;
#if V8_HOST_ARCH_X64
uint64_t size;
char* code_ptr = getsectdatafromheader_64(
reinterpret_cast<const mach_header_64*>(header),
SEG_TEXT,
SECT_TEXT,
&size);
#else
unsigned int size;
char* code_ptr = getsectdatafromheader(header, SEG_TEXT, SECT_TEXT, &size);
#endif
if (code_ptr == NULL) continue;
const uintptr_t slide = _dyld_get_image_vmaddr_slide(i);
const uintptr_t start = reinterpret_cast<uintptr_t>(code_ptr) + slide;
LOG(Isolate::Current(),
SharedLibraryEvent(_dyld_get_image_name(i), start, start + size));
}
#endif // ENABLE_LOGGING_AND_PROFILING
}
void OS::SignalCodeMovingGC() {
}
uint64_t OS::CpuFeaturesImpliedByPlatform() {
// MacOSX requires all these to install so we can assume they are present.
// These constants are defined by the CPUid instructions.
const uint64_t one = 1;
return (one << SSE2) | (one << CMOV) | (one << RDTSC) | (one << CPUID);
}
int OS::ActivationFrameAlignment() {
// OS X activation frames must be 16 byte-aligned; see "Mac OS X ABI
// Function Call Guide".
return 16;
}
void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
OSMemoryBarrier();
*ptr = value;
}
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));
}
int OS::StackWalk(Vector<StackFrame> frames) {
// If weak link to execinfo lib has failed, ie because we are on 10.4, abort.
if (backtrace == NULL)
return 0;
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;
}
VirtualMemory::VirtualMemory(size_t size) {
address_ = mmap(NULL, size, PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
kMmapFd, kMmapFdOffset);
size_ = size;
}
VirtualMemory::~VirtualMemory() {
if (IsReserved()) {
if (0 == munmap(address(), size())) address_ = MAP_FAILED;
}
}
bool VirtualMemory::IsReserved() {
return address_ != MAP_FAILED;
}
bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
if (MAP_FAILED == mmap(address, size, prot,
MAP_PRIVATE | MAP_ANON | MAP_FIXED,
kMmapFd, kMmapFdOffset)) {
return false;
}
UpdateAllocatedSpaceLimits(address, size);
return true;
}
bool VirtualMemory::Uncommit(void* address, size_t size) {
return mmap(address, size, PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED,
kMmapFd, kMmapFdOffset) != MAP_FAILED;
}
class Thread::PlatformData : public Malloced {
public:
PlatformData() : thread_(kNoThread) {}
pthread_t thread_; // Thread handle for pthread.
};
Thread::Thread(Isolate* isolate, const Options& options)
: data_(new PlatformData),
isolate_(isolate),
stack_size_(options.stack_size) {
set_name(options.name);
}
Thread::Thread(Isolate* isolate, const char* name)
: data_(new PlatformData),
isolate_(isolate),
stack_size_(0) {
set_name(name);
}
Thread::~Thread() {
delete data_;
}
static void SetThreadName(const char* name) {
// pthread_setname_np is only available in 10.6 or later, so test
// for it at runtime.
int (*dynamic_pthread_setname_np)(const char*);
*reinterpret_cast<void**>(&dynamic_pthread_setname_np) =
dlsym(RTLD_DEFAULT, "pthread_setname_np");
if (!dynamic_pthread_setname_np)
return;
// Mac OS X does not expose the length limit of the name, so hardcode it.
static const int kMaxNameLength = 63;
USE(kMaxNameLength);
ASSERT(Thread::kMaxThreadNameLength <= kMaxNameLength);
dynamic_pthread_setname_np(name);
}
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();
SetThreadName(thread->name());
ASSERT(thread->data()->thread_ != kNoThread);
Thread::SetThreadLocal(Isolate::isolate_key(), thread->isolate());
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);
}
#ifdef V8_FAST_TLS_SUPPORTED
static Atomic32 tls_base_offset_initialized = 0;
intptr_t kMacTlsBaseOffset = 0;
// It's safe to do the initialization more that once, but it has to be
// done at least once.
static void InitializeTlsBaseOffset() {
const size_t kBufferSize = 128;
char buffer[kBufferSize];
size_t buffer_size = kBufferSize;
int ctl_name[] = { CTL_KERN , KERN_OSRELEASE };
if (sysctl(ctl_name, 2, buffer, &buffer_size, NULL, 0) != 0) {
V8_Fatal(__FILE__, __LINE__, "V8 failed to get kernel version");
}
// The buffer now contains a string of the form XX.YY.ZZ, where
// XX is the major kernel version component.
// Make sure the buffer is 0-terminated.
buffer[kBufferSize - 1] = '\0';
char* period_pos = strchr(buffer, '.');
*period_pos = '\0';
int kernel_version_major =
static_cast<int>(strtol(buffer, NULL, 10)); // NOLINT
// The constants below are taken from pthreads.s from the XNU kernel
// sources archive at www.opensource.apple.com.
if (kernel_version_major < 11) {
// 8.x.x (Tiger), 9.x.x (Leopard), 10.x.x (Snow Leopard) have the
// same offsets.
#if defined(V8_HOST_ARCH_IA32)
kMacTlsBaseOffset = 0x48;
#else
kMacTlsBaseOffset = 0x60;
#endif
} else {
// 11.x.x (Lion) changed the offset.
kMacTlsBaseOffset = 0;
}
Release_Store(&tls_base_offset_initialized, 1);
}
static void CheckFastTls(Thread::LocalStorageKey key) {
void* expected = reinterpret_cast<void*>(0x1234CAFE);
Thread::SetThreadLocal(key, expected);
void* actual = Thread::GetExistingThreadLocal(key);
if (expected != actual) {
V8_Fatal(__FILE__, __LINE__,
"V8 failed to initialize fast TLS on current kernel");
}
Thread::SetThreadLocal(key, NULL);
}
#endif // V8_FAST_TLS_SUPPORTED
Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
#ifdef V8_FAST_TLS_SUPPORTED
bool check_fast_tls = false;
if (tls_base_offset_initialized == 0) {
check_fast_tls = true;
InitializeTlsBaseOffset();
}
#endif
pthread_key_t key;
int result = pthread_key_create(&key, NULL);
USE(result);
ASSERT(result == 0);
LocalStorageKey typed_key = static_cast<LocalStorageKey>(key);
#ifdef V8_FAST_TLS_SUPPORTED
// If we just initialized fast TLS support, make sure it works.
if (check_fast_tls) CheckFastTls(typed_key);
#endif
return typed_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 MacOSMutex : public Mutex {
public:
MacOSMutex() {
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
pthread_mutex_init(&mutex_, &attr);
}
virtual ~MacOSMutex() { pthread_mutex_destroy(&mutex_); }
virtual int Lock() { return pthread_mutex_lock(&mutex_); }
virtual int Unlock() { return pthread_mutex_unlock(&mutex_); }
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_;
};
Mutex* OS::CreateMutex() {
return new MacOSMutex();
}
class MacOSSemaphore : public Semaphore {
public:
explicit MacOSSemaphore(int count) {
semaphore_create(mach_task_self(), &semaphore_, SYNC_POLICY_FIFO, count);
}
~MacOSSemaphore() {
semaphore_destroy(mach_task_self(), semaphore_);
}
// The MacOS mach semaphore documentation claims it does not have spurious
// wakeups, the way pthreads semaphores do. So the code from the linux
// platform is not needed here.
void Wait() { semaphore_wait(semaphore_); }
bool Wait(int timeout);
void Signal() { semaphore_signal(semaphore_); }
private:
semaphore_t semaphore_;
};
bool MacOSSemaphore::Wait(int timeout) {
mach_timespec_t ts;
ts.tv_sec = timeout / 1000000;
ts.tv_nsec = (timeout % 1000000) * 1000;
return semaphore_timedwait(semaphore_, ts) != KERN_OPERATION_TIMED_OUT;
}
Semaphore* OS::CreateSemaphore(int count) {
return new MacOSSemaphore(count);
}
#ifdef ENABLE_LOGGING_AND_PROFILING
class Sampler::PlatformData : public Malloced {
public:
PlatformData() : profiled_thread_(mach_thread_self()) {}
~PlatformData() {
// Deallocate Mach port for thread.
mach_port_deallocate(mach_task_self(), profiled_thread_);
}
thread_act_t profiled_thread() { return profiled_thread_; }
private:
// Note: for profiled_thread_ Mach primitives are used instead of PThread's
// because the latter doesn't provide thread manipulation primitives required.
// For details, consult "Mac OS X Internals" book, Section 7.3.
thread_act_t profiled_thread_;
};
class SamplerThread : public Thread {
public:
explicit SamplerThread(int interval)
: Thread(NULL, "SamplerThread"),
interval_(interval) {}
static void AddActiveSampler(Sampler* sampler) {
ScopedLock lock(mutex_);
SamplerRegistry::AddActiveSampler(sampler);
if (instance_ == NULL) {
instance_ = new SamplerThread(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::WakeUpRuntimeProfilerThreadBeforeShutdown();
instance_->Join();
delete instance_;
instance_ = NULL;
}
}
// 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) {
if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
return;
}
}
if (runtime_profiler_enabled) {
if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
return;
}
}
OS::Sleep(interval_);
}
}
static void DoCpuProfile(Sampler* sampler, void* raw_sampler_thread) {
if (!sampler->isolate()->IsInitialized()) return;
if (!sampler->IsProfiling()) return;
SamplerThread* sampler_thread =
reinterpret_cast<SamplerThread*>(raw_sampler_thread);
sampler_thread->SampleContext(sampler);
}
static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
if (!sampler->isolate()->IsInitialized()) return;
sampler->isolate()->runtime_profiler()->NotifyTick();
}
void SampleContext(Sampler* sampler) {
thread_act_t profiled_thread = sampler->platform_data()->profiled_thread();
TickSample sample_obj;
TickSample* sample = CpuProfiler::TickSampleEvent(sampler->isolate());
if (sample == NULL) sample = &sample_obj;
if (KERN_SUCCESS != thread_suspend(profiled_thread)) return;
#if V8_HOST_ARCH_X64
thread_state_flavor_t flavor = x86_THREAD_STATE64;
x86_thread_state64_t state;
mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;
#if __DARWIN_UNIX03
#define REGISTER_FIELD(name) __r ## name
#else
#define REGISTER_FIELD(name) r ## name
#endif // __DARWIN_UNIX03
#elif V8_HOST_ARCH_IA32
thread_state_flavor_t flavor = i386_THREAD_STATE;
i386_thread_state_t state;
mach_msg_type_number_t count = i386_THREAD_STATE_COUNT;
#if __DARWIN_UNIX03
#define REGISTER_FIELD(name) __e ## name
#else
#define REGISTER_FIELD(name) e ## name
#endif // __DARWIN_UNIX03
#else
#error Unsupported Mac OS X host architecture.
#endif // V8_HOST_ARCH
if (thread_get_state(profiled_thread,
flavor,
reinterpret_cast<natural_t*>(&state),
&count) == KERN_SUCCESS) {
sample->state = sampler->isolate()->current_vm_state();
sample->pc = reinterpret_cast<Address>(state.REGISTER_FIELD(ip));
sample->sp = reinterpret_cast<Address>(state.REGISTER_FIELD(sp));
sample->fp = reinterpret_cast<Address>(state.REGISTER_FIELD(bp));
sampler->SampleStack(sample);
sampler->Tick(sample);
}
thread_resume(profiled_thread);
}
const int interval_;
RuntimeProfilerRateLimiter rate_limiter_;
// Protects the process wide state below.
static Mutex* mutex_;
static SamplerThread* instance_;
DISALLOW_COPY_AND_ASSIGN(SamplerThread);
};
#undef REGISTER_FIELD
Mutex* SamplerThread::mutex_ = OS::CreateMutex();
SamplerThread* SamplerThread::instance_ = NULL;
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);
SamplerThread::AddActiveSampler(this);
}
void Sampler::Stop() {
ASSERT(IsActive());
SamplerThread::RemoveActiveSampler(this);
SetActive(false);
}
#endif // ENABLE_LOGGING_AND_PROFILING
} } // namespace v8::internal