[NaCl SDK] Upate atomic ops in nacl_io

native_client_sdk/src/libraries/sdk_util/ref_object.h

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef LIBRARIES_SDK_UTIL_REF_OBJECT
 #define LIBRARIES_SDK_UTIL_REF_OBJECT
 
 #include <stdlib.h>
 #include "pthread.h"
 
 #include "sdk_util/atomicops.h"
 
 class ScopedRefBase;
 
 /*
  * RefObject
  *
- * A reference counted object with a lock.  The lock protects the data within
- * the object, but not the reference counting which happens through atomic
- * operations.  RefObjects should only be handled by ScopedRef objects.
+ * A reference counted object. RefObjects should only be handled by ScopedRef
+ * objects.
  *
  * When the object is first created, it has a reference count of zero.  It's
  * first incremented when it gets assigned to a ScopedRef.  When the last
  * ScopedRef is reset or destroyed the object will get released.
  */
 
 class RefObject {
  public:
   RefObject() {
     ref_count_ = 0;
-    pthread_mutex_init(&lock_, NULL);
   }
 
   /*
    * RefCount
    *
    * RefCount returns an instantaneous snapshot of the RefCount, which may
    * change immediately after it is fetched.  This is only stable when all
    * pointers to the object are scoped pointers (ScopedRef), and the value
    * is one implying the current thread is the only one, with visibility to
    * the object.
    */
   int RefCount() const { return ref_count_; }
 
  protected:
+  virtual ~RefObject() {}
+
+  // Override to clean up object when last reference is released.
+  virtual void Destroy() {}
+
   void Acquire() {
     AtomicAddFetch(&ref_count_, 1);
   }
 
   bool Release() {
     Atomic32 val = AtomicAddFetch(&ref_count_, -1);
     if (val == 0) {
       Destroy();
       delete this;
       return false;
     }
     return true;
   }
 
-  virtual ~RefObject() {
-    pthread_mutex_destroy(&lock_);
-  }
-
-  // Override to clean up object when last reference is released.
-  virtual void Destroy() {}
-  pthread_mutex_t lock_;
-
  private:
   Atomic32 ref_count_;
 
   friend class ScopedRefBase;
 };
 
 #endif  // LIBRARIES_SDK_UTIL_REF_OBJECT