1 files changed, 12 insertions, 93 deletions

diff --git a/include/llvm/Support/Mutex.h b/include/llvm/Support/Mutex.h
index c3abfc7a7806..1d8a0d3c87cb 100644
--- a/include/llvm/Support/Mutex.h
+++ b/include/llvm/Support/Mutex.h
@@ -13,97 +13,31 @@
 #ifndef LLVM_SUPPORT_MUTEX_H
 #define LLVM_SUPPORT_MUTEX_H
 
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Threading.h"
 #include <cassert>
+#include <mutex>
 
 namespace llvm
 {
   namespace sys
   {
-    /// Platform agnostic Mutex class.
-    class MutexImpl
-    {
-    /// @name Constructors
-    /// @{
-    public:
-
-      /// Initializes the lock but doesn't acquire it. if \p recursive is set
-      /// to false, the lock will not be recursive which makes it cheaper but
-      /// also more likely to deadlock (same thread can't acquire more than
-      /// once).
-      /// Default Constructor.
-      explicit MutexImpl(bool recursive = true);
-
-      /// Releases and removes the lock
-      /// Destructor
-      ~MutexImpl();
-
-    /// @}
-    /// @name Methods
-    /// @{
-    public:
-
-      /// Attempts to unconditionally acquire the lock. If the lock is held by
-      /// another thread, this method will wait until it can acquire the lock.
-      /// @returns false if any kind of error occurs, true otherwise.
-      /// Unconditionally acquire the lock.
-      bool acquire();
-
-      /// Attempts to release the lock. If the lock is held by the current
-      /// thread, the lock is released allowing other threads to acquire the
-      /// lock.
-      /// @returns false if any kind of error occurs, true otherwise.
-      /// Unconditionally release the lock.
-      bool release();
-
-      /// Attempts to acquire the lock without blocking. If the lock is not
-      /// available, this function returns false quickly (without blocking). If
-      /// the lock is available, it is acquired.
-      /// @returns false if any kind of error occurs or the lock is not
-      /// available, true otherwise.
-      /// Try to acquire the lock.
-      bool tryacquire();
-
-    //@}
-    /// @name Platform Dependent Data
-    /// @{
-    private:
-#if defined(LLVM_ENABLE_THREADS) && LLVM_ENABLE_THREADS != 0
-      void* data_; ///< We don't know what the data will be
-#endif
-
-    /// @}
-    /// @name Do Not Implement
-    /// @{
-    private:
-      MutexImpl(const MutexImpl &) = delete;
-      void operator=(const MutexImpl &) = delete;
-    /// @}
-    };
-
-
     /// SmartMutex - A mutex with a compile time constant parameter that
     /// indicates whether this mutex should become a no-op when we're not
     /// running in multithreaded mode.
     template<bool mt_only>
     class SmartMutex {
-      MutexImpl impl;
-      unsigned acquired;
-      bool recursive;
-    public:
-      explicit SmartMutex(bool rec = true) :
-        impl(rec), acquired(0), recursive(rec) { }
+      std::recursive_mutex impl;
+      unsigned acquired = 0;
 
+    public:
       bool lock() {
         if (!mt_only || llvm_is_multithreaded()) {
-          return impl.acquire();
+          impl.lock();
+          return true;
         } else {
           // Single-threaded debugging code.  This would be racy in
           // multithreaded mode, but provides not sanity checks in single
           // threaded mode.
-          assert((recursive || acquired == 0) && "Lock already acquired!!");
           ++acquired;
           return true;
         }
@@ -111,13 +45,13 @@ namespace llvm
 
       bool unlock() {
         if (!mt_only || llvm_is_multithreaded()) {
-          return impl.release();
+          impl.unlock();
+          return true;
         } else {
           // Single-threaded debugging code.  This would be racy in
           // multithreaded mode, but provides not sanity checks in single
           // threaded mode.
-          assert(((recursive && acquired) || (acquired == 1)) &&
-                 "Lock not acquired before release!");
+          assert(acquired && "Lock not acquired before release!");
           --acquired;
           return true;
         }
@@ -125,31 +59,16 @@ namespace llvm
 
       bool try_lock() {
         if (!mt_only || llvm_is_multithreaded())
-          return impl.tryacquire();
+          return impl.try_lock();
         else return true;
       }
-
-      private:
-        SmartMutex(const SmartMutex<mt_only> & original);
-        void operator=(const SmartMutex<mt_only> &);
     };
 
     /// Mutex - A standard, always enforced mutex.
     typedef SmartMutex<false> Mutex;
 
-    template<bool mt_only>
-    class SmartScopedLock  {
-      SmartMutex<mt_only>& mtx;
-
-    public:
-      SmartScopedLock(SmartMutex<mt_only>& m) : mtx(m) {
-        mtx.lock();
-      }
-
-      ~SmartScopedLock() {
-        mtx.unlock();
-      }
-    };
+    template <bool mt_only>
+    using SmartScopedLock = std::lock_guard<SmartMutex<mt_only>>;
 
     typedef SmartScopedLock<false> ScopedLock;
   }