| // Copyright 2013 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/base/platform/semaphore.h" |
| |
| #if V8_OS_MACOSX |
| #include <mach/mach_init.h> |
| #include <mach/task.h> |
| #endif |
| |
| #include <errno.h> |
| |
| #include "src/base/logging.h" |
| #include "src/base/platform/elapsed-timer.h" |
| #include "src/base/platform/time.h" |
| |
| namespace v8 { |
| namespace base { |
| |
| #if V8_OS_MACOSX |
| |
| Semaphore::Semaphore(int count) { |
| kern_return_t result = semaphore_create( |
| mach_task_self(), &native_handle_, SYNC_POLICY_FIFO, count); |
| DCHECK_EQ(KERN_SUCCESS, result); |
| USE(result); |
| } |
| |
| |
| Semaphore::~Semaphore() { |
| kern_return_t result = semaphore_destroy(mach_task_self(), native_handle_); |
| DCHECK_EQ(KERN_SUCCESS, result); |
| USE(result); |
| } |
| |
| void Semaphore::Signal() { |
| kern_return_t result = semaphore_signal(native_handle_); |
| DCHECK_EQ(KERN_SUCCESS, result); |
| USE(result); |
| } |
| |
| |
| void Semaphore::Wait() { |
| while (true) { |
| kern_return_t result = semaphore_wait(native_handle_); |
| if (result == KERN_SUCCESS) return; // Semaphore was signalled. |
| DCHECK_EQ(KERN_ABORTED, result); |
| } |
| } |
| |
| |
| bool Semaphore::WaitFor(const TimeDelta& rel_time) { |
| TimeTicks now = TimeTicks::Now(); |
| TimeTicks end = now + rel_time; |
| while (true) { |
| mach_timespec_t ts; |
| if (now >= end) { |
| // Return immediately if semaphore was not signalled. |
| ts.tv_sec = 0; |
| ts.tv_nsec = 0; |
| } else { |
| ts = (end - now).ToMachTimespec(); |
| } |
| kern_return_t result = semaphore_timedwait(native_handle_, ts); |
| if (result == KERN_SUCCESS) return true; // Semaphore was signalled. |
| if (result == KERN_OPERATION_TIMED_OUT) return false; // Timeout. |
| DCHECK_EQ(KERN_ABORTED, result); |
| now = TimeTicks::Now(); |
| } |
| } |
| |
| #elif V8_OS_POSIX |
| |
| Semaphore::Semaphore(int count) { |
| // The sem_init() does not check for alignment of the native handle. |
| // Unaligned native handle can later cause a failure in semaphore signal. |
| // Check the alignment here to catch the failure earlier. |
| // Context: crbug.com/605349. |
| #if V8_OS_AIX |
| // On aix sem_t is of type int |
| const uintptr_t kSemaphoreAlignmentMask = sizeof(int) - 1; |
| #else |
| const uintptr_t kSemaphoreAlignmentMask = sizeof(void*) - 1; |
| #endif |
| CHECK_EQ( |
| 0, reinterpret_cast<uintptr_t>(&native_handle_) & |
| kSemaphoreAlignmentMask); |
| DCHECK(count >= 0); |
| #if V8_LIBC_GLIBC |
| // sem_init in glibc prior to 2.1 does not zero out semaphores. |
| memset(&native_handle_, 0, sizeof(native_handle_)); |
| #endif |
| int result = sem_init(&native_handle_, 0, count); |
| DCHECK_EQ(0, result); |
| USE(result); |
| } |
| |
| |
| Semaphore::~Semaphore() { |
| int result = sem_destroy(&native_handle_); |
| DCHECK_EQ(0, result); |
| USE(result); |
| } |
| |
| void Semaphore::Signal() { |
| int result = sem_post(&native_handle_); |
| CHECK_EQ(0, result); |
| } |
| |
| |
| void Semaphore::Wait() { |
| while (true) { |
| int result = sem_wait(&native_handle_); |
| if (result == 0) return; // Semaphore was signalled. |
| // Signal caused spurious wakeup. |
| DCHECK_EQ(-1, result); |
| DCHECK_EQ(EINTR, errno); |
| } |
| } |
| |
| |
| bool Semaphore::WaitFor(const TimeDelta& rel_time) { |
| #if V8_OS_NACL |
| // PNaCL doesn't support sem_timedwait, do ugly busy waiting. |
| ElapsedTimer timer; |
| timer.Start(); |
| do { |
| int result = sem_trywait(&native_handle_); |
| if (result == 0) return true; |
| DCHECK(errno == EAGAIN || errno == EINTR); |
| } while (!timer.HasExpired(rel_time)); |
| return false; |
| #else |
| // Compute the time for end of timeout. |
| const Time time = Time::NowFromSystemTime() + rel_time; |
| const struct timespec ts = time.ToTimespec(); |
| |
| // Wait for semaphore signalled or timeout. |
| while (true) { |
| int result = sem_timedwait(&native_handle_, &ts); |
| if (result == 0) return true; // Semaphore was signalled. |
| #if V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4) |
| if (result > 0) { |
| // sem_timedwait in glibc prior to 2.3.4 returns the errno instead of -1. |
| errno = result; |
| result = -1; |
| } |
| #endif |
| if (result == -1 && errno == ETIMEDOUT) { |
| // Timed out while waiting for semaphore. |
| return false; |
| } |
| // Signal caused spurious wakeup. |
| DCHECK_EQ(-1, result); |
| DCHECK_EQ(EINTR, errno); |
| } |
| #endif |
| } |
| |
| #elif V8_OS_WIN |
| |
| Semaphore::Semaphore(int count) { |
| DCHECK(count >= 0); |
| native_handle_ = ::CreateSemaphoreA(NULL, count, 0x7fffffff, NULL); |
| DCHECK(native_handle_ != NULL); |
| } |
| |
| |
| Semaphore::~Semaphore() { |
| BOOL result = CloseHandle(native_handle_); |
| DCHECK(result); |
| USE(result); |
| } |
| |
| void Semaphore::Signal() { |
| LONG dummy; |
| BOOL result = ReleaseSemaphore(native_handle_, 1, &dummy); |
| DCHECK(result); |
| USE(result); |
| } |
| |
| |
| void Semaphore::Wait() { |
| DWORD result = WaitForSingleObject(native_handle_, INFINITE); |
| DCHECK(result == WAIT_OBJECT_0); |
| USE(result); |
| } |
| |
| |
| bool Semaphore::WaitFor(const TimeDelta& rel_time) { |
| TimeTicks now = TimeTicks::Now(); |
| TimeTicks end = now + rel_time; |
| while (true) { |
| int64_t msec = (end - now).InMilliseconds(); |
| if (msec >= static_cast<int64_t>(INFINITE)) { |
| DWORD result = WaitForSingleObject(native_handle_, INFINITE - 1); |
| if (result == WAIT_OBJECT_0) { |
| return true; |
| } |
| DCHECK(result == WAIT_TIMEOUT); |
| now = TimeTicks::Now(); |
| } else { |
| DWORD result = WaitForSingleObject( |
| native_handle_, (msec < 0) ? 0 : static_cast<DWORD>(msec)); |
| if (result == WAIT_TIMEOUT) { |
| return false; |
| } |
| DCHECK(result == WAIT_OBJECT_0); |
| return true; |
| } |
| } |
| } |
| |
| #endif // V8_OS_MACOSX |
| |
| } // namespace base |
| } // namespace v8 |