critical_section.h

/*
    Copyright 2005-2010 Intel Corporation.  All Rights Reserved.

    The source code contained or described herein and all documents related
    to the source code ("Material") are owned by Intel Corporation or its
    suppliers or licensors.  Title to the Material remains with Intel
    Corporation or its suppliers and licensors.  The Material is protected
    by worldwide copyright laws and treaty provisions.  No part of the
    Material may be used, copied, reproduced, modified, published, uploaded,
    posted, transmitted, distributed, or disclosed in any way without
    Intel's prior express written permission.

    No license under any patent, copyright, trade secret or other
    intellectual property right is granted to or conferred upon you by
    disclosure or delivery of the Materials, either expressly, by
    implication, inducement, estoppel or otherwise.  Any license under such
    intellectual property rights must be express and approved by Intel in
    writing.
*/

#ifndef _TBB_CRITICAL_SECTION_H_
#define _TBB_CRITICAL_SECTION_H_

#if _WIN32||_WIN64
#include <windows.h>
#else
#include <pthread.h>
#include <errno.h>
#endif  // _WIN32||WIN64

#include "tbb_stddef.h"
#include "tbb_thread.h"
#include "tbb_exception.h"

#include "tbb_profiling.h"

namespace tbb {

    namespace internal {
class critical_section_v4 : internal::no_copy {
#if _WIN32||_WIN64
    CRITICAL_SECTION my_impl;
#else
    pthread_mutex_t my_impl;
#endif
    tbb_thread::id my_tid;
public:

    void __TBB_EXPORTED_METHOD internal_construct();

    critical_section_v4() { 
#if _WIN32||_WIN64
        InitializeCriticalSection(&my_impl);
#else
        pthread_mutex_init(&my_impl, NULL);
#endif
        internal_construct();
    }

    ~critical_section_v4() {
        __TBB_ASSERT(my_tid == tbb_thread::id(), "Destroying a still-held critical section");
#if _WIN32||_WIN64
        DeleteCriticalSection(&my_impl); 
#else
        pthread_mutex_destroy(&my_impl);
#endif
    }

    class scoped_lock : internal::no_copy {
    private:
        critical_section_v4 &my_crit;
    public:
        scoped_lock( critical_section_v4& lock_me) :my_crit(lock_me) {
            my_crit.lock();
        }

        ~scoped_lock() {
            my_crit.unlock();
        }
    };

    void lock() { 
        tbb_thread::id local_tid = this_tbb_thread::get_id();
        if(local_tid == my_tid) throw_exception( eid_improper_lock );
#if _WIN32||_WIN64
        EnterCriticalSection( &my_impl );
#else
        int rval = pthread_mutex_lock(&my_impl);
        __TBB_ASSERT_EX(!rval, "critical_section::lock: pthread_mutex_lock failed");
#endif
        __TBB_ASSERT(my_tid == tbb_thread::id(), NULL);
        my_tid = local_tid;
    }

    bool try_lock() {
        bool gotlock;
        tbb_thread::id local_tid = this_tbb_thread::get_id();
        if(local_tid == my_tid) return false;
#if _WIN32||_WIN64
        gotlock = TryEnterCriticalSection( &my_impl ) != 0;
#else
        int rval = pthread_mutex_trylock(&my_impl);
        // valid returns are 0 (locked) and [EBUSY]
        __TBB_ASSERT(rval == 0 || rval == EBUSY, "critical_section::trylock: pthread_mutex_trylock failed");
        gotlock = rval == 0;
#endif
        if(gotlock)  {
            my_tid = local_tid;
        }
        return gotlock;
    }

    void unlock() {
        __TBB_ASSERT(this_tbb_thread::get_id() == my_tid, "thread unlocking critical_section is not thread that locked it");
        my_tid = tbb_thread::id();
#if _WIN32||_WIN64
        LeaveCriticalSection( &my_impl );
#else
        int rval = pthread_mutex_unlock(&my_impl);
        __TBB_ASSERT_EX(!rval, "critical_section::unlock: pthread_mutex_unlock failed");
#endif
    }

    static const bool is_rw_mutex = false;
    static const bool is_recursive_mutex = false;
    static const bool is_fair_mutex = true;
}; // critical_section_v4
} // namespace internal
typedef internal::critical_section_v4 critical_section;

__TBB_DEFINE_PROFILING_SET_NAME(critical_section)
} // namespace tbb
#endif  // _TBB_CRITICAL_SECTION_H_

---

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