Added a wait with timeout to the platform semaphore class

src/platform-linux.cc

 // 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
@@ skipping 574 matching lines @@
   return new LinuxMutex();
 }
 
 
 class LinuxSemaphore : public Semaphore {
  public:
   explicit LinuxSemaphore(int count) {  sem_init(&sem_, 0, count); }
   virtual ~LinuxSemaphore() { sem_destroy(&sem_); }
 
   virtual void Wait();
+  virtual bool Wait(int timeout);
   virtual void Signal() { sem_post(&sem_); }
  private:
   sem_t sem_;
 };
 
+
 void LinuxSemaphore::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 LinuxSemaphore::Wait(int timeout) {
+  const long kOneSecondMicros = 1000000;  // NOLINT
+  const long kOneSecondNanos = 1000000000;  // NOLINT
+
+  // Split timeout into second and nanosecond parts.
+  long nanos = (timeout % kOneSecondMicros) * 1000;  // NOLINT
+  time_t secs = timeout / kOneSecondMicros;
+
+  // Get the current realtime clock.
+  struct timespec ts;
+  if (clock_gettime(CLOCK_REALTIME, &ts) == -1) {
+    return false;
+  }
+
+  // Calculate real time for end of timeout.
+  ts.tv_nsec += nanos;
+  if (ts.tv_nsec >= kOneSecondNanos) {
+    ts.tv_nsec -= kOneSecondNanos;
+    ts.tv_nsec++;
+  }
+  ts.tv_sec += secs;
+
+  // Wait for semaphore signalled or timeout.
+  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 LinuxSemaphore(count);
 }
 
 
 // ----------------------------------------------------------------------------
 // Linux socket support.
 //
 
 class LinuxSocket : public Socket {
@@ skipping 236 matching lines @@
   }
 
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
   active_ = false;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal