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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:13:27 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:13:27 +0000 |
commit | 40a355a42d4a9444dc753c04c6608dade2f06a23 (patch) | |
tree | 871fc667d2de662f171103ce5ec067014ef85e61 /third_party/libwebrtc/api/ref_count.h | |
parent | Adding upstream version 124.0.1. (diff) | |
download | firefox-40a355a42d4a9444dc753c04c6608dade2f06a23.tar.xz firefox-40a355a42d4a9444dc753c04c6608dade2f06a23.zip |
Adding upstream version 125.0.1.upstream/125.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/api/ref_count.h')
-rw-r--r-- | third_party/libwebrtc/api/ref_count.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/ref_count.h b/third_party/libwebrtc/api/ref_count.h new file mode 100644 index 0000000000..5209277038 --- /dev/null +++ b/third_party/libwebrtc/api/ref_count.h @@ -0,0 +1,67 @@ +/* + * Copyright 2011 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 API_REF_COUNT_H_ +#define API_REF_COUNT_H_ + +namespace webrtc { + +// Refcounted objects should implement the following informal interface: +// +// void AddRef() const ; +// RefCountReleaseStatus Release() const; +// +// You may access members of a reference-counted object, including the AddRef() +// and Release() methods, only if you already own a reference to it, or if +// you're borrowing someone else's reference. (A newly created object is a +// special case: the reference count is zero on construction, and the code that +// creates the object should immediately call AddRef(), bringing the reference +// count from zero to one, e.g., by constructing an rtc::scoped_refptr). +// +// AddRef() creates a new reference to the object. +// +// Release() releases a reference to the object; the caller now has one less +// reference than before the call. Returns kDroppedLastRef if the number of +// references dropped to zero because of this (in which case the object destroys +// itself). Otherwise, returns kOtherRefsRemained, to signal that at the precise +// time the caller's reference was dropped, other references still remained (but +// if other threads own references, this may of course have changed by the time +// Release() returns). +// +// The caller of Release() must treat it in the same way as a delete operation: +// Regardless of the return value from Release(), the caller mustn't access the +// object. The object might still be alive, due to references held by other +// users of the object, but the object can go away at any time, e.g., as the +// result of another thread calling Release(). +// +// Calling AddRef() and Release() manually is discouraged. It's recommended to +// use rtc::scoped_refptr to manage all pointers to reference counted objects. +// Note that rtc::scoped_refptr depends on compile-time duck-typing; formally +// implementing the below RefCountInterface is not required. + +enum class RefCountReleaseStatus { kDroppedLastRef, kOtherRefsRemained }; + +// Interfaces where refcounting is part of the public api should +// inherit this abstract interface. The implementation of these +// methods is usually provided by the RefCountedObject template class, +// applied as a leaf in the inheritance tree. +class RefCountInterface { + public: + virtual void AddRef() const = 0; + virtual RefCountReleaseStatus Release() const = 0; + + // Non-public destructor, because Release() has exclusive responsibility for + // destroying the object. + protected: + virtual ~RefCountInterface() {} +}; + +} // namespace webrtc + +#endif // API_REF_COUNT_H_ |