cuberite-2a/src/OSSupport/Semaphore.cpp

#include "Globals.h"  // NOTE: MSVC stupidness requires this to be the same across all modules





cSemaphore::cSemaphore( unsigned int a_MaxCount, unsigned int a_InitialCount /* = 0 */ )
#ifndef _WIN32
	: m_bNamed( false )
#endif
{
#ifndef _WIN32
	(void)a_MaxCount;
	m_Handle = new sem_t;
	if (sem_init( (sem_t*)m_Handle, 0, 0))
	{
		LOG("WARNING cSemaphore: Could not create unnamed semaphore, fallback to named.");
		delete (sem_t*)m_Handle;    // named semaphores return their own address
		m_bNamed = true;

		AString Name;
		Printf(Name, "cSemaphore%p", this );
		m_Handle = sem_open(Name.c_str(), O_CREAT, 777, a_InitialCount);
		if( m_Handle == SEM_FAILED )
		{
			LOG("ERROR: Could not create Semaphore. (%i)", errno );
		}
		else
		{
			if( sem_unlink(Name.c_str()) != 0 )
			{
				LOG("ERROR: Could not unlink cSemaphore. (%i)", errno);
			}
		}
	}
#else
	m_Handle = CreateSemaphore(
		NULL, // security attribute
		a_InitialCount, // initial count
		a_MaxCount, // maximum count
		0 // name (optional)
		);
#endif
}

cSemaphore::~cSemaphore()
{
#ifdef _WIN32
	CloseHandle( m_Handle );
#else
    if( m_bNamed )
    {
        if( sem_close( (sem_t*)m_Handle ) != 0 )
        {
            LOG("ERROR: Could not close cSemaphore. (%i)", errno);
        }
    }
    else
    {
        sem_destroy( (sem_t*)m_Handle );
        delete (sem_t*)m_Handle;
    }
	m_Handle = 0;

#endif
}

void cSemaphore::Wait()
{
#ifndef _WIN32
    if( sem_wait( (sem_t*)m_Handle ) != 0)
    {
        LOG("ERROR: Could not wait for cSemaphore. (%i)", errno);
    }
#else
	WaitForSingleObject( m_Handle, INFINITE);
#endif
}

void cSemaphore::Signal()
{
#ifndef _WIN32
	if( sem_post( (sem_t*)m_Handle ) != 0 )
	{
        LOG("ERROR: Could not signal cSemaphore. (%i)", errno);
	}
#else
	ReleaseSemaphore( m_Handle, 1, NULL );
#endif
}