Initial commit: Final state of the master project

Research/inc/tbb/queuing_mutex.h

@@ -0,0 +1,123 @@
+/*
+    Copyright 2005-2015 Intel Corporation.  All Rights Reserved.
+
+    This file is part of Threading Building Blocks. Threading Building Blocks is free software;
+    you can redistribute it and/or modify it under the terms of the GNU General Public License
+    version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks is
+    distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
+    implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+    See  the GNU General Public License for more details.   You should have received a copy of
+    the  GNU General Public License along with Threading Building Blocks; if not, write to the
+    Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA
+
+    As a special exception,  you may use this file  as part of a free software library without
+    restriction.  Specifically,  if other files instantiate templates  or use macros or inline
+    functions from this file, or you compile this file and link it with other files to produce
+    an executable,  this file does not by itself cause the resulting executable to be covered
+    by the GNU General Public License. This exception does not however invalidate any other
+    reasons why the executable file might be covered by the GNU General Public License.
+*/
+
+#ifndef __TBB_queuing_mutex_H
+#define __TBB_queuing_mutex_H
+
+#include "tbb_config.h"
+
+#if !TBB_USE_EXCEPTIONS && _MSC_VER
+    // Suppress "C++ exception handler used, but unwind semantics are not enabled" warning in STL headers
+    #pragma warning (push)
+    #pragma warning (disable: 4530)
+#endif
+
+#include <cstring>
+
+#if !TBB_USE_EXCEPTIONS && _MSC_VER
+    #pragma warning (pop)
+#endif
+
+#include "atomic.h"
+#include "tbb_profiling.h"
+
+namespace tbb {
+
+//! Queuing mutex with local-only spinning.
+/** @ingroup synchronization */
+class queuing_mutex : internal::mutex_copy_deprecated_and_disabled {
+public:
+    //! Construct unacquired mutex.
+    queuing_mutex() {
+        q_tail = NULL;
+#if TBB_USE_THREADING_TOOLS
+        internal_construct();
+#endif
+    }
+
+    //! The scoped locking pattern
+    /** It helps to avoid the common problem of forgetting to release lock.
+        It also nicely provides the "node" for queuing locks. */
+    class scoped_lock: internal::no_copy {
+        //! Initialize fields to mean "no lock held".
+        void initialize() {
+            mutex = NULL;
+#if TBB_USE_ASSERT
+            internal::poison_pointer(next);
+#endif /* TBB_USE_ASSERT */
+        }
+
+    public:
+        //! Construct lock that has not acquired a mutex.
+        /** Equivalent to zero-initialization of *this. */
+        scoped_lock() {initialize();}
+
+        //! Acquire lock on given mutex.
+        scoped_lock( queuing_mutex& m ) {
+            initialize();
+            acquire(m);
+        }
+
+        //! Release lock (if lock is held).
+        ~scoped_lock() {
+            if( mutex ) release();
+        }
+
+        //! Acquire lock on given mutex.
+        void __TBB_EXPORTED_METHOD acquire( queuing_mutex& m );
+
+        //! Acquire lock on given mutex if free (i.e. non-blocking)
+        bool __TBB_EXPORTED_METHOD try_acquire( queuing_mutex& m );
+
+        //! Release lock.
+        void __TBB_EXPORTED_METHOD release();
+
+    private:
+        //! The pointer to the mutex owned, or NULL if not holding a mutex.
+        queuing_mutex* mutex;
+
+        //! The pointer to the next competitor for a mutex
+        scoped_lock *next;
+
+        //! The local spin-wait variable
+        /** Inverted (0 - blocked, 1 - acquired the mutex) for the sake of
+            zero-initialization.  Defining it as an entire word instead of
+            a byte seems to help performance slightly. */
+        uintptr_t going;
+    };
+
+    void __TBB_EXPORTED_METHOD internal_construct();
+
+    // Mutex traits
+    static const bool is_rw_mutex = false;
+    static const bool is_recursive_mutex = false;
+    static const bool is_fair_mutex = true;
+
+private:
+    //! The last competitor requesting the lock
+    atomic<scoped_lock*> q_tail;
+
+};
+
+__TBB_DEFINE_PROFILING_SET_NAME(queuing_mutex)
+
+} // namespace tbb
+
+#endif /* __TBB_queuing_mutex_H */