CSemaphore_WIN.cpp

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */

#include "base-precomp.h"  // Precompiled headers



#include <mrpt/config.h>

#ifdef MRPT_OS_WINDOWS

#include <windows.h>

#include <mrpt/synch/CSemaphore.h>
#include <mrpt/utils/CStream.h>

using namespace mrpt;
using namespace mrpt::synch;

/*---------------------------------------------------------------
                                                CSemaphore
---------------------------------------------------------------*/
CSemaphore::CSemaphore(
    unsigned int    initialCount,
    unsigned int    maxCount)
{
        MRPT_START

        HANDLE hSem = CreateSemaphoreA(
                NULL,                   // pointer to security attributes
                initialCount,   // initial count
                maxCount,               // maximum count
                NULL /*name*/ );

        if (!hSem)      THROW_EXCEPTION("Error creating semaphore!");

        m_data.resize( sizeof(HANDLE) );

        * m_data.getAsPtr<HANDLE>() = hSem;

        MRPT_END
}

/*---------------------------------------------------------------
                                                ~CSemaphore
---------------------------------------------------------------*/
CSemaphore::~CSemaphore()
{
        if (m_data.alias_count()==1)
        {
                CloseHandle( * m_data.getAsPtr<HANDLE>() );
        }
}

/*---------------------------------------------------------------
Blocks until the count of the semaphore to be non-zero.
\param timeout_ms The timeout in milliseconds, or set to zero to wait indefinidely.
\return true if the semaphore has been signaled, false on timeout or any other error.
---------------------------------------------------------------*/
bool CSemaphore::waitForSignal( unsigned int timeout_ms )
{
        MRPT_START

        DWORD tim = (timeout_ms==0) ? INFINITE : timeout_ms;
        DWORD ret = WaitForSingleObject( * m_data.getAsPtr<HANDLE>(), tim );

        return (ret==WAIT_OBJECT_0);

        MRPT_END
}

/*---------------------------------------------------------------
        Increments the count of the semaphore by a given amount.
---------------------------------------------------------------*/
void CSemaphore::release(unsigned int increaseCount )
{
        MRPT_START

        if (!ReleaseSemaphore(
                *m_data.getAsPtr<HANDLE>(),             // handle of the semaphore object
                increaseCount,          // amount to add to current count
                NULL ))                         // address of previous count
                        THROW_EXCEPTION("Error increasing semaphore count!");

        MRPT_END
}


#endif // Windows