1193323Sed//===-- Support/MutexGuard.h - Acquire/Release Mutex In Scope ---*- C++ -*-===// 2193323Sed// 3193323Sed// The LLVM Compiler Infrastructure 4193323Sed// 5193323Sed// This file is distributed under the University of Illinois Open Source 6193323Sed// License. See LICENSE.TXT for details. 7193323Sed// 8193323Sed//===----------------------------------------------------------------------===// 9193323Sed// 10193323Sed// This file defines a guard for a block of code that ensures a Mutex is locked 11193323Sed// upon construction and released upon destruction. 12193323Sed// 13193323Sed//===----------------------------------------------------------------------===// 14193323Sed 15193323Sed#ifndef LLVM_SUPPORT_MUTEXGUARD_H 16193323Sed#define LLVM_SUPPORT_MUTEXGUARD_H 17193323Sed 18218893Sdim#include "llvm/Support/Mutex.h" 19193323Sed 20193323Sednamespace llvm { 21193323Sed /// Instances of this class acquire a given Mutex Lock when constructed and 22193323Sed /// hold that lock until destruction. The intention is to instantiate one of 23193323Sed /// these on the stack at the top of some scope to be assured that C++ 24193323Sed /// destruction of the object will always release the Mutex and thus avoid 25193323Sed /// a host of nasty multi-threading problems in the face of exceptions, etc. 26193323Sed /// @brief Guard a section of code with a Mutex. 27193323Sed class MutexGuard { 28193323Sed sys::Mutex &M; 29245431Sdim MutexGuard(const MutexGuard &) LLVM_DELETED_FUNCTION; 30245431Sdim void operator=(const MutexGuard &) LLVM_DELETED_FUNCTION; 31193323Sed public: 32193323Sed MutexGuard(sys::Mutex &m) : M(m) { M.acquire(); } 33193323Sed ~MutexGuard() { M.release(); } 34193323Sed /// holds - Returns true if this locker instance holds the specified lock. 35193323Sed /// This is mostly used in assertions to validate that the correct mutex 36193323Sed /// is held. 37193323Sed bool holds(const sys::Mutex& lock) const { return &M == &lock; } 38193323Sed }; 39193323Sed} 40193323Sed 41193323Sed#endif // LLVM_SUPPORT_MUTEXGUARD_H 42