Revert the latest set of platform changes.

src/platform-posix.cc

 // Copyright 2012 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 738 matching lines @@
 
 
 void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
   pthread_key_t pthread_key = LocalKeyToPthreadKey(key);
   int result = pthread_setspecific(pthread_key, value);
   ASSERT_EQ(0, result);
   USE(result);
 }
 
 
+class POSIXMutex : public Mutex {
+ public:
+  POSIXMutex() {
+    pthread_mutexattr_t attr;
+    memset(&attr, 0, sizeof(attr));
+    int result = pthread_mutexattr_init(&attr);
+    ASSERT(result == 0);
+    result = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    ASSERT(result == 0);
+    result = pthread_mutex_init(&mutex_, &attr);
+    ASSERT(result == 0);
+    result = pthread_mutexattr_destroy(&attr);
+    ASSERT(result == 0);
+    USE(result);
+  }
+
+  virtual ~POSIXMutex() { 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_;   // Pthread mutex for POSIX platforms.
+};
+
+
+Mutex* OS::CreateMutex() {
+  return new POSIXMutex();
+}
+
+
 // ----------------------------------------------------------------------------
 // POSIX socket support.
 //
 
 class POSIXSocket : public Socket {
  public:
   explicit POSIXSocket() {
     // Create the socket.
     socket_ = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
     if (IsValid()) {
@@ skipping 179 matching lines @@
   return ntohl(value);
 }
 
 
 Socket* OS::CreateSocket() {
   return new POSIXSocket();
 }
 
 
 } }  // namespace v8::internal