Added a wait with timeout to the platform semaphore class

src/platform.h

 // 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 392 matching lines @@
 // A semaphore object is a synchronization object that maintains a count. The
 // count is decremented each time a thread completes a wait for the semaphore
 // object and incremented each time a thread signals the semaphore. When the
 // count reaches zero,  threads waiting for the semaphore blocks until the
 // count becomes non-zero.
 
 class Semaphore {
  public:
   virtual ~Semaphore() {}
 
-  // Suspends the calling thread until the counter is non zero
+  // Suspends the calling thread until the semaphore counter is non zero
   // and then decrements the semaphore counter.
   virtual void Wait() = 0;
 
+  // Suspends the calling thread until the counter is non zero or the timeout
+  // time has passsed. If timeout happens the return value is false and the
+  // counter is unchanged. Otherwise the semaphore counter is decremented and
+  // true is returned. The timeout value is specified in microseconds.
+  virtual bool Wait(int timeout) = 0;
+
   // Increments the semaphore counter.
   virtual void Signal() = 0;
 };
 
 
 // ----------------------------------------------------------------------------
 // Socket
 //
 
 class Socket {
@@ skipping 71 matching lines @@
   bool active_;
   PlatformData* data_;  // Platform specific data.
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_H_