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/*
* Copyright 2017 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef RTC_BASE_REFCOUNTER_H_
#define RTC_BASE_REFCOUNTER_H_
#include "rtc_base/atomicops.h"
#include "rtc_base/refcount.h"
namespace webrtc {
namespace webrtc_impl {
class RefCounter {
public:
explicit RefCounter(int ref_count) : ref_count_(ref_count) {}
RefCounter() = delete;
void IncRef() { rtc::AtomicOps::Increment(&ref_count_); }
// TODO(nisse): Switch return type to RefCountReleaseStatus?
// Returns true if this was the last reference, and the resource protected by
// the reference counter can be deleted.
rtc::RefCountReleaseStatus DecRef() {
return (rtc::AtomicOps::Decrement(&ref_count_) == 0)
? rtc::RefCountReleaseStatus::kDroppedLastRef
: rtc::RefCountReleaseStatus::kOtherRefsRemained;
}
// Return whether the reference count is one. If the reference count is used
// in the conventional way, a reference count of 1 implies that the current
// thread owns the reference and no other thread shares it. This call performs
// the test for a reference count of one, and performs the memory barrier
// needed for the owning thread to act on the resource protected by the
// reference counter, knowing that it has exclusive access.
bool HasOneRef() const {
return rtc::AtomicOps::AcquireLoad(&ref_count_) == 1;
}
private:
volatile int ref_count_;
};
} // namespace webrtc_impl
} // namespace webrtc
#endif // RTC_BASE_REFCOUNTER_H_
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