source: Sophya/trunk/SophyaExt/JThreadsC++/JTCSrc/Event.cpp@ 1016

// **********************************************************************
//
// Copyright (c) 2000
// Object Oriented Concepts, Inc.
// Billerica, MA, USA
//
// All Rights Reserved
//
// **********************************************************************

#include <JTC/Types.h>
#include <JTC/Syscall.h>
#include <JTC/Mutex.h>
#include <JTC/Event.h>
#include <JTC/Cond.h>
#include <JTC/Monitor.h>
#include <JTC/Sync.h>
#include <JTC/Exception.h>

#include <errno.h>

#ifdef HAVE_STD_IOSTREAM
using namespace std;
#endif

//
// This class encapsulates the functionality of a WIN32 event
// semaphore.
//

// ----------------------------------------------------------------------
// JTCEvent constructor and destructor
// ----------------------------------------------------------------------

JTCEvent::JTCEvent()

#ifndef WIN32
    : posted_(false)
#endif

{
#if defined(HAVE_POSIX_THREADS)
    JTC_SYSCALL_2(pthread_cond_init, &cond_, 0, != 0)
#endif

#if defined(HAVE_DCE_THREADS)
    JTC_SYSCALL_2(pthread_cond_init, &cond_, pthread_condattr_default, != 0)
#endif

#if defined(HAVE_WIN32_THREADS)
    JTC_SYSCALL_4(event_ = CreateEvent, 0, 1, 0, 0, == INVALID_HANDLE_VALUE)
#endif
}

JTCEvent::~JTCEvent()
{
#if defined(HAVE_POSIX_THREADS) || defined(HAVE_DCE_THREADS)
    pthread_cond_destroy(&cond_);
#endif

#if defined(HAVE_WIN32_THREADS)
    CloseHandle(event_);
#endif
}

// ----------------------------------------------------------------------
// JTCEvent public member implementation
// ----------------------------------------------------------------------

//
// Set the state of the event object to signalled. Wake any waiting
// threads.
//
void
JTCEvent::post()
{
#if defined(HAVE_POSIX_THREADS) || defined(HAVE_DCE_THREADS)
    JTCSynchronized sync(mut_);
    posted_ = true;

    //
    // Wake up all waiters.
    //
    JTC_SYSCALL_1(pthread_cond_broadcast, &cond_, != 0)
#endif

#if defined(HAVE_WIN32_THREADS)
    JTC_SYSCALL_1(SetEvent, event_, == 0)
#endif
}

//
// Wake any waiting threads.
//
void
JTCEvent::pulse()
{
#if defined(HAVE_POSIX_THREADS) || defined(HAVE_DCE_THREADS)
    JTCSynchronized sync(mut_);

    posted_ = false;

    //
    // Wake up one waiter.
    //
    JTC_SYSCALL_1(pthread_cond_signal, &cond_, != 0)
#endif
#if defined(HAVE_WIN32_THREADS)
    JTC_SYSCALL_1(PulseEvent, event_, == 0)
#endif
}

//
// Wait for the event object to become signalled.
//
void
JTCEvent::wait()
{
#if defined(HAVE_POSIX_THREADS) || defined(HAVE_DCE_THREADS)
    //
    // We want to lock the internal mutex. If we're not currently
    // posted then wait on the condition variable. next unlock the
    // internal mutex,
    //
    JTCSynchronized sync(mut_);
    if(!posted_)
    {
        for(;;)
        {
            try
            {
                JTC_SYSCALL_2(pthread_cond_wait, &cond_, &mut_.lock_, < 0)
            }
            catch(const JTCSystemCallException& e)
            {
                if(e.getError() == EINTR)
                    continue;
                throw;
            }
            break;
        }
    }
#endif

#if defined(HAVE_WIN32_THREADS)
    JTC_SYSCALL_2(WaitForSingleObject,event_, INFINITE, != WAIT_OBJECT_0)
#endif
}

//
// Set the state of the event object to unsignalled.
//
void
JTCEvent::reset()
{
#if defined(HAVE_POSIX_THREADS) || defined(HAVE_DCE_THREADS)
    JTCSynchronized sync(mut_);
    posted_ = false;
#endif

#if defined(HAVE_WIN32_THREADS)
    JTC_SYSCALL_1(ResetEvent, event_, == 0)
#endif
}

//
// Determine if the event object is signalled.
//
bool
JTCEvent::posted()
{
#if defined(HAVE_POSIX_THREADS) || defined(HAVE_DCE_THREADS)
    JTCSynchronized sync(mut_);
    return posted_;
#endif

#if defined(HAVE_WIN32_THREADS)
    long rc;
    JTC_SYSCALL_2(rc = WaitForSingleObject, event_, 0, == WAIT_FAILED)
    return rc != WAIT_TIMEOUT;
#endif
}