111 lines
2.0 KiB
C++
111 lines
2.0 KiB
C++
/* SPDX-License-Identifier: MIT */
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/**
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@file lock.h
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@brief Declares the AJALock class.
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@copyright (C) 2009-2021 AJA Video Systems, Inc. All rights reserved.
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**/
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#ifndef AJA_LOCK_H
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#define AJA_LOCK_H
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#include "ajabase/common/public.h"
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#if defined(AJA_USE_CPLUSPLUS11)
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#include <mutex>
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#include <string>
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using std::recursive_timed_mutex;
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using std::string;
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#endif
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#define LOCK_TIME_INFINITE 0xffffffff
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// forward declarations
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class AJALockImpl;
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/**
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* Class to coordinate access to non reentrant code.
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* @ingroup AJAGroupSystem
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*/
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class AJA_EXPORT AJALock
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{
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public:
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/**
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* Constructor obtains a lockable object from the system.
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*
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* Specify a name if the lock is to be shared system wide.
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*
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* @param pName Name of a shared lock object.
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*/
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AJALock(const char* pName = NULL);
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virtual ~AJALock();
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/**
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* Request the lock.
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*
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* @param[in] timeout Request timeout in milliseconds (0xffffffff infinite).
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* @return AJA_STATUS_SUCCESS Object locked
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* AJA_STATUS_TIMEOUT Lock wait timeout
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* AJA_STATUS_OPEN Lock not initialized
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* AJA_STATUS_FAIL Lock failed
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*/
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virtual AJAStatus Lock(uint32_t timeout = LOCK_TIME_INFINITE);
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/**
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* Release the lock.
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*
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* @return AJA_STATUS_SUCCESS Lock released
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* AJA_STATUS_OPEN Lock not initialized
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*/
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virtual AJAStatus Unlock();
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/**
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* @return True if valid (has implementation).
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* False if not valid.
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*/
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virtual inline bool IsValid(void) const
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{
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#if defined(AJA_USE_CPLUSPLUS11)
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return mpMutex != nullptr;
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#else
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return mpImpl != NULL;
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#endif
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}
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private:
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#if defined(AJA_USE_CPLUSPLUS11)
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recursive_timed_mutex* mpMutex={nullptr};
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string name;
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#else
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AJALockImpl* mpImpl;
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#endif
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};
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/**
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* Automatically obtain and release a lock.
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*/
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class AJA_EXPORT AJAAutoLock
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{
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public:
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/**
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* Constructor waits for lock.
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*
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* @param[in] pLock The required lock.
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*/
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AJAAutoLock(AJALock* pLock = NULL);
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/**
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* Destructor releases lock.
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*/
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virtual ~AJAAutoLock();
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private:
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AJALock* mpLock;
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};
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#endif // AJA_LOCK_H
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