Cleanup Semaphore class.

src/platform/semaphore.cc

+// Copyright 2013 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.
+
+#include "platform/semaphore.h"
+
+#if V8_OS_MACOSX
+#include <mach/mach_init.h>
+#include <mach/task.h>
+#endif
+
+#include <cerrno>
+
+#include "checks.h"
+#include "platform/time.h"
+
+namespace v8 {
+namespace internal {
+
+#if V8_OS_MACOSX
+
+Semaphore::Semaphore(int count) {
+  kern_return_t result = semaphore_create(
+      mach_task_self(), &native_handle_, SYNC_POLICY_FIFO, count);
+  ASSERT_EQ(KERN_SUCCESS, result);
+  USE(result);
+}
+
+
+Semaphore::~Semaphore() {
+  kern_return_t result = semaphore_destroy(mach_task_self(), native_handle_);
+  ASSERT_EQ(KERN_SUCCESS, result);
+  USE(result);
+}
+
+
+void Semaphore::Signal() {
+  kern_return_t result = semaphore_signal(native_handle_);
+  ASSERT_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.
+    ASSERT_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.
+    ASSERT_EQ(KERN_ABORTED, result);
+    now = TimeTicks::Now();
+  }
+}
+
+#elif V8_OS_POSIX
+
+Semaphore::Semaphore(int count) {
+  ASSERT(count >= 0);
+  int result = sem_init(&native_handle_, 0, count);
+  ASSERT_EQ(0, result);
+  USE(result);
+}
+
+
+Semaphore::~Semaphore() {
+  int result = sem_destroy(&native_handle_);
+  ASSERT_EQ(0, result);
+  USE(result);
+}
+
+
+void Semaphore::Signal() {
+  int result = sem_post(&native_handle_);
+  ASSERT_EQ(0, result);
+  USE(result);
+}
+
+
+void Semaphore::Wait() {
+  while (true) {
+    int result = sem_wait(&native_handle_);
+    if (result == 0) return;  // Semaphore was signalled.
+    // Signal caused spurious wakeup.
+    ASSERT_EQ(-1, result);
+    ASSERT_EQ(EINTR, errno);
+  }
+}
+
+
+bool Semaphore::WaitFor(const TimeDelta& rel_time) {
+  // 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.
+    ASSERT_EQ(-1, result);
+    ASSERT_EQ(EINTR, errno);
+  }
+}
+
+#elif V8_OS_WIN
+
+Semaphore::Semaphore(int count) {
+  ASSERT(count >= 0);
+  native_handle_ = ::CreateSemaphoreA(NULL, count, 0x7fffffff, NULL);
+  ASSERT(native_handle_ != NULL);
+}
+
+
+Semaphore::~Semaphore() {
+  BOOL result = CloseHandle(native_handle_);
+  ASSERT(result);
+  USE(result);
+}
+
+
+void Semaphore::Signal() {
+  LONG dummy;
+  BOOL result = ReleaseSemaphore(native_handle_, 1, &dummy);
+  ASSERT(result);
+  USE(result);
+}
+
+
+void Semaphore::Wait() {
+  DWORD result = WaitForSingleObject(native_handle_, INFINITE);
+  ASSERT(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;
+      }
+      ASSERT(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;
+      }
+      ASSERT(result == WAIT_OBJECT_0);
+      return true;
+    }
+  }
+}
+
+#endif  // V8_OS_MACOSX
+
+} }  // namespace v8::internal