X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FMutexGuard.h;h=21c756d50b94174ace7326b18d0c1ef608161580;hb=80a75bfae980df96f969f1c05b0c4a80ce975240;hp=427e0c3a22074e0b8e7459e3e444eefef0995165;hpb=4046846d2cb36a6281b853c73776584063cca19d;p=oota-llvm.git

diff --git a/include/llvm/Support/MutexGuard.h b/include/llvm/Support/MutexGuard.h
index 427e0c3a220..21c756d50b9 100644
--- a/include/llvm/Support/MutexGuard.h
+++ b/include/llvm/Support/MutexGuard.h
@@ -1,42 +1,41 @@
-//===-- Support/ThreadSupport.h - Generic threading support -----*- C++ -*-===//
-// 
+//===-- Support/MutexGuard.h - Acquire/Release Mutex In Scope ---*- C++ -*-===//
+//
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by the LLVM research group and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+//
 //===----------------------------------------------------------------------===//
 //
-// This file defines platform-agnostic interfaces that can be used to write
-// multi-threaded programs.  Autoconf is used to chose the correct
-// implementation of these interfaces, or default to a non-thread-capable system
-// if no matching system support is available.
+// This file defines a guard for a block of code that ensures a Mutex is locked
+// upon construction and released upon destruction.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_THREADSUPPORT_H
-#define SUPPORT_THREADSUPPORT_H
-
-#undef HAVE_PTHREAD_MUTEX_LOCK
+#ifndef LLVM_SUPPORT_MUTEXGUARD_H
+#define LLVM_SUPPORT_MUTEXGUARD_H
 
-#ifdef HAVE_PTHREAD_MUTEX_LOCK
-#include "llvm/Support/ThreadSupport-PThreads.h"
-#else
-#include "llvm/Support/ThreadSupport-NoSupport.h"
-#endif // If no system support is available
+#include <llvm/System/Mutex.h>
 
 namespace llvm {
-  /// MutexLocker - Instances of this class acquire a given Lock when
-  /// constructed and hold that lock until destruction.
-  ///
-  class MutexLocker {
-    Mutex &M;
-    MutexLocker(const MutexLocker &);    // DO NOT IMPLEMENT
-    void operator=(const MutexLocker &); // DO NOT IMPLEMENT
+  /// Instances of this class acquire a given Mutex Lock when constructed and
+  /// hold that lock until destruction. The intention is to instantiate one of
+  /// these on the stack at the top of some scope to be assured that C++
+  /// destruction of the object will always release the Mutex and thus avoid
+  /// a host of nasty multi-threading problems in the face of exceptions, etc.
+  /// @brief Guard a section of code with a Mutex.
+  class MutexGuard {
+    sys::Mutex &M;
+    MutexGuard(const MutexGuard &);    // DO NOT IMPLEMENT
+    void operator=(const MutexGuard &); // DO NOT IMPLEMENT
   public:
-    MutexLocker(Mutex &m) : M(m) { M.acquire(); }
-    ~MutexLocker() { M.release(); }
+    MutexGuard(sys::Mutex &m) : M(m) { M.acquire(); }
+    ~MutexGuard() { M.release(); }
+    /// holds - Returns true if this locker instance holds the specified lock.
+    /// This is mostly used in assertions to validate that the correct mutex
+    /// is held.
+    bool holds(const sys::Mutex& lock) const { return &M == &lock; }
   };
 }
 
-#endif // SUPPORT_THREADSUPPORT_H
+#endif // LLVM_SUPPORT_MUTEXGUARD_H