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