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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /security/sandbox/chromium/base/sequence_token.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'security/sandbox/chromium/base/sequence_token.h')
-rw-r--r-- | security/sandbox/chromium/base/sequence_token.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/sequence_token.h b/security/sandbox/chromium/base/sequence_token.h new file mode 100644 index 0000000000..6e7d191ae8 --- /dev/null +++ b/security/sandbox/chromium/base/sequence_token.h @@ -0,0 +1,115 @@ +// Copyright 2016 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 BASE_SEQUENCE_TOKEN_H_ +#define BASE_SEQUENCE_TOKEN_H_ + +#include "base/base_export.h" +#include "base/macros.h" + +namespace base { + +// A token that identifies a series of sequenced tasks (i.e. tasks that run one +// at a time in posting order). +class BASE_EXPORT SequenceToken { + public: + // Instantiates an invalid SequenceToken. + SequenceToken() = default; + + // Explicitly allow copy. + SequenceToken(const SequenceToken& other) = default; + SequenceToken& operator=(const SequenceToken& other) = default; + + // An invalid SequenceToken is not equal to any other SequenceToken, including + // other invalid SequenceTokens. + bool operator==(const SequenceToken& other) const; + bool operator!=(const SequenceToken& other) const; + + // Returns true if this is a valid SequenceToken. + bool IsValid() const; + + // Returns the integer uniquely representing this SequenceToken. This method + // should only be used for tracing and debugging. + int ToInternalValue() const; + + // Returns a valid SequenceToken which isn't equal to any previously returned + // SequenceToken. + static SequenceToken Create(); + + // Returns the SequenceToken associated with the task running on the current + // thread, as determined by the active ScopedSetSequenceTokenForCurrentThread + // if any. + static SequenceToken GetForCurrentThread(); + + private: + explicit SequenceToken(int token) : token_(token) {} + + static constexpr int kInvalidSequenceToken = -1; + int token_ = kInvalidSequenceToken; +}; + +// A token that identifies a task. +// +// This is used by ThreadCheckerImpl to determine whether calls to +// CalledOnValidThread() come from the same task and hence are deterministically +// single-threaded (vs. calls coming from different sequenced or parallel tasks, +// which may or may not run on the same thread). +class BASE_EXPORT TaskToken { + public: + // Instantiates an invalid TaskToken. + TaskToken() = default; + + // Explicitly allow copy. + TaskToken(const TaskToken& other) = default; + TaskToken& operator=(const TaskToken& other) = default; + + // An invalid TaskToken is not equal to any other TaskToken, including + // other invalid TaskTokens. + bool operator==(const TaskToken& other) const; + bool operator!=(const TaskToken& other) const; + + // Returns true if this is a valid TaskToken. + bool IsValid() const; + + // In the scope of a ScopedSetSequenceTokenForCurrentThread, returns a valid + // TaskToken which isn't equal to any TaskToken returned in the scope of a + // different ScopedSetSequenceTokenForCurrentThread. Otherwise, returns an + // invalid TaskToken. + static TaskToken GetForCurrentThread(); + + private: + friend class ScopedSetSequenceTokenForCurrentThread; + + explicit TaskToken(int token) : token_(token) {} + + // Returns a valid TaskToken which isn't equal to any previously returned + // TaskToken. This is private as it only meant to be instantiated by + // ScopedSetSequenceTokenForCurrentThread. + static TaskToken Create(); + + static constexpr int kInvalidTaskToken = -1; + int token_ = kInvalidTaskToken; +}; + +// Instantiate this in the scope where a single task runs. +class BASE_EXPORT ScopedSetSequenceTokenForCurrentThread { + public: + // Throughout the lifetime of the constructed object, + // SequenceToken::GetForCurrentThread() will return |sequence_token| and + // TaskToken::GetForCurrentThread() will return a TaskToken which is not equal + // to any TaskToken returned in the scope of another + // ScopedSetSequenceTokenForCurrentThread. + ScopedSetSequenceTokenForCurrentThread(const SequenceToken& sequence_token); + ~ScopedSetSequenceTokenForCurrentThread(); + + private: + const SequenceToken sequence_token_; + const TaskToken task_token_; + + DISALLOW_COPY_AND_ASSIGN(ScopedSetSequenceTokenForCurrentThread); +}; + +} // namespace base + +#endif // BASE_SEQUENCE_TOKEN_H_ |