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//===-- Support/MutexGuard.h - Acquire/Release Mutex In Scope ---*- C++ -*-===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file defines a guard for a block of code that ensures a Mutex is locked
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// upon construction and released upon destruction.
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_SUPPORT_MUTEXGUARD_H
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#define LLVM_SUPPORT_MUTEXGUARD_H
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#include "llvm/System/Mutex.h"
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/// Instances of this class acquire a given Mutex Lock when constructed and
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/// hold that lock until destruction. The intention is to instantiate one of
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/// these on the stack at the top of some scope to be assured that C++
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/// destruction of the object will always release the Mutex and thus avoid
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/// a host of nasty multi-threading problems in the face of exceptions, etc.
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/// @brief Guard a section of code with a Mutex.
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MutexGuard(const MutexGuard &); // DO NOT IMPLEMENT
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void operator=(const MutexGuard &); // DO NOT IMPLEMENT
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MutexGuard(sys::Mutex &m) : M(m) { M.acquire(); }
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~MutexGuard() { M.release(); }
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/// holds - Returns true if this locker instance holds the specified lock.
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/// This is mostly used in assertions to validate that the correct mutex
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bool holds(const sys::Mutex& lock) const { return &M == &lock; }
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#endif // LLVM_SUPPORT_MUTEXGUARD_H