synchronized.h

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/*
* Copyright (c) 2011-2012 MLBA-Team. All rights reserved.
*
* @MLBA_OPEN_LICENSE_HEADER_START@
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @MLBA_OPEN_LICENSE_HEADER_END@
*/



#ifndef SYNCHRONIZED_H_
#define SYNCHRONIZED_H_

#ifndef __XDISPATCH_INDIRECT__
#error "Please #include <xdispatch/dispatch.h> instead of this file directly."
#endif

#include <string>

__XDISPATCH_BEGIN_NAMESPACE

class XDISPATCH_EXPORT synclock;


class XDISPATCH_EXPORT synclock {

public:
    synclock();
    synclock(const synclock&);
    ~synclock();

    operator bool() const;

    void unlock();

private:
    struct data;
    data* _d;

    synclock& operator= (synclock);

    friend XDISPATCH_EXPORT synclock get_lock_for_key(const std::string&);
    friend XDISPATCH_EXPORT synclock get_lock_for_key( dispatch_semaphore_t );
    synclock(dispatch_semaphore_t);
};


XDISPATCH_EXPORT void init_semaphore_for_synclock(void*);
XDISPATCH_EXPORT XDISPATCH_DEPRECATED( synclock get_lock_for_key(const std::string& key) );
inline synclock get_lock_for_key( dispatch_semaphore_t sem ){ return synclock(sem); }
inline synclock get_lock_for_key( synclock& s ){ return s; }


# define XDISPATCH_CONCAT(A,B) A ## B
# define XDISPATCH_LOCK_VAR(X) XDISPATCH_CONCAT(xd_synclock_, X)
# define XDISPATCH_LOCK_VAR_SEM(X) XDISPATCH_CONCAT( __xd_synclock_sem_, X)
# define XDISPATCH_LOCK_VAR_ONCE(X) XDISPATCH_CONCAT( __xd_synclock_once_, X)
# define XDISPATCH_SYNC_HEADER( lock ) for( xdispatch::synclock XDISPATCH_LOCK_VAR(__LINE__)(lock) ; XDISPATCH_LOCK_VAR(__LINE__) ; XDISPATCH_LOCK_VAR(__LINE__).unlock() )
# define XDISPATCH_SYNC_DECL( id ) \
    static dispatch_semaphore_t XDISPATCH_LOCK_VAR_SEM( id ); \
    static dispatch_once_t XDISPATCH_LOCK_VAR_ONCE( id ); \
    dispatch_once_f( &XDISPATCH_LOCK_VAR_ONCE( id ), &XDISPATCH_LOCK_VAR_SEM( id ), xdispatch::init_semaphore_for_synclock ); \
    XDISPATCH_SYNC_HEADER( xdispatch::get_lock_for_key( XDISPATCH_LOCK_VAR_SEM( id ) ) )

#  define XDISPATCH_SYNCHRONIZE( lock ) XDISPATCH_SYNC_HEADER( xdispatch::get_lock_for_key( lock ) )

#  define XDISPATCH_SYNCHRONIZED XDISPATCH_SYNC_DECL( __COUNTER__ )

#ifndef XDISPATCH_NO_KEYWORDS
# ifndef synchronize
#  define synchronize( lock ) XDISPATCH_SYNCHRONIZE(lock)
# endif

# ifndef synchronized
#  define synchronized XDISPATCH_SYNCHRONIZED
# endif
#endif

__XDISPATCH_END_NAMESPACE

#endif /* SYNCHRONIZED_H_ */