53 lines
1.8 KiB
C
53 lines
1.8 KiB
C
|
/*
|
||
|
|
* 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_
|