1 //===-- Support/MutexGuard.h - Acquire/Release Mutex In Scope ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a guard for a block of code that ensures a Mutex is locked
11 // upon construction and released upon destruction.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_SUPPORT_MUTEXGUARD_H
16 #define LLVM_SUPPORT_MUTEXGUARD_H
18 #include <llvm/System/Mutex.h>
21 /// Instances of this class acquire a given Mutex Lock when constructed and
22 /// hold that lock until destruction. The intention is to instantiate one of
23 /// these on the stack at the top of some scope to be assured that C++
24 /// destruction of the object will always release the Mutex and thus avoid
25 /// a host of nasty multi-threading problems in the face of exceptions, etc.
26 /// @brief Guard a section of code with a Mutex.
29 MutexGuard(const MutexGuard &); // DO NOT IMPLEMENT
30 void operator=(const MutexGuard &); // DO NOT IMPLEMENT
32 MutexGuard(sys::Mutex &m) : M(m) { M.acquire(); }
33 ~MutexGuard() { M.release(); }
34 /// holds - Returns true if this locker instance holds the specified lock.
35 /// This is mostly used in assertions to validate that the correct mutex
37 bool holds(const sys::Mutex& lock) const { return &M == &lock; }
41 #endif // LLVM_SUPPORT_MUTEXGUARD_H