Tcl Source Code

typedef struct TclPipeThreadInfo {
    HANDLE evControl;		/* Auto-reset event used by the main thread to
				 * signal when the pipe thread should attempt
				 * to do read/write operation. Additionally
				 * used as signal to stop (state set to -1) */
    volatile LONG state;	/* Indicates current state of the thread */
    void *clientData;		/* Referenced data of the main thread */
    HANDLE evWakeUp;		/* Optional wake-up event worker set by shutdown */
} TclPipeThreadInfo;

/* If pipe-workers will use some tcl subsystem, we can use Tcl_Alloc without
 * more overhead for finalize thread (should be executed anyway)
 *
 * #define _PTI_USE_CKALLOC 1
 */

    PTI_STATE_STOP = 2,		/* thread should stop work (owns TI structure) */
    PTI_STATE_END = 4,		/* thread should stop work (worker is busy) */
    PTI_STATE_DOWN = 8		/* worker is down */
};

MODULE_SCOPE
TclPipeThreadInfo *	TclPipeThreadCreateTI(TclPipeThreadInfo **pipeTIPtr,
			    void *clientData, HANDLE wakeEvent);
MODULE_SCOPE int	TclPipeThreadWaitForSignal(
			    TclPipeThreadInfo **pipeTIPtr);

static inline void
TclPipeThreadSignal(
    TclPipeThreadInfo **pipeTIPtr)
{

    if (readFile != NULL) {
	/*
	 * Start the background reader thread.
	 */

	infoPtr->readable = CreateEventW(NULL, TRUE, TRUE, NULL);
	infoPtr->readThread = CreateThread(NULL, 256, PipeReaderThread,
	    TclPipeThreadCreateTI(&infoPtr->readTI, infoPtr, infoPtr->readable),
	    0, NULL);
	SetThreadPriority(infoPtr->readThread, THREAD_PRIORITY_HIGHEST);
	infoPtr->validMask |= TCL_READABLE;
    } else {
	infoPtr->readTI = NULL;
	infoPtr->readThread = 0;
    }
    if (writeFile != NULL) {
	/*
	 * Start the background writer thread.
	 */

	infoPtr->writable = CreateEventW(NULL, TRUE, TRUE, NULL);
	infoPtr->writeThread = CreateThread(NULL, 256, PipeWriterThread,
	    TclPipeThreadCreateTI(&infoPtr->writeTI, infoPtr, infoPtr->writable),
	    0, NULL);
	SetThreadPriority(infoPtr->writeThread, THREAD_PRIORITY_HIGHEST);
	infoPtr->validMask |= TCL_WRITABLE;
    } else {
	infoPtr->writeTI = NULL;
	infoPtr->writeThread = 0;
    }

 *
 *----------------------------------------------------------------------
 */

TclPipeThreadInfo *
TclPipeThreadCreateTI(
    TclPipeThreadInfo **pipeTIPtr,
    void *clientData,
    HANDLE wakeEvent)
{
    TclPipeThreadInfo *pipeTI;
#ifndef _PTI_USE_CKALLOC
    pipeTI = (TclPipeThreadInfo *)malloc(sizeof(TclPipeThreadInfo));
#else
    pipeTI = (TclPipeThreadInfo *)Tcl_Alloc(sizeof(TclPipeThreadInfo));
#endif /* !_PTI_USE_CKALLOC */
    pipeTI->evControl = CreateEventW(NULL, FALSE, FALSE, NULL);
    pipeTI->state = PTI_STATE_IDLE;
    pipeTI->clientData = clientData;
    pipeTI->evWakeUp = wakeEvent;
    return (*pipeTIPtr = pipeTI);
}

/*
 *----------------------------------------------------------------------
 *
 * TclPipeThreadWaitForSignal --

int
TclPipeThreadWaitForSignal(
    TclPipeThreadInfo **pipeTIPtr)
{
    TclPipeThreadInfo *pipeTI = *pipeTIPtr;
    LONG state;
    DWORD waitResult;
    HANDLE wakeEvent;

    if (!pipeTI) {
	return 0;
    }

    wakeEvent = pipeTI->evWakeUp;

    /*
     * Wait for the main thread to signal before attempting to do the work.
     */

    /*
     * Reset work state of thread (idle/waiting)
     */

  end:
    /*
     * End of work, check the owner of the TI structure.
     */

    if (state != PTI_STATE_STOP) {
	*pipeTIPtr = NULL;
    } else {
	pipeTI->evWakeUp = NULL;
    }
    if (wakeEvent) {
	SetEvent(wakeEvent);
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *

    HANDLE evControl;
    int state;

    if (!pipeTI) {
	return 1;
    }
    evControl = pipeTI->evControl;
    pipeTI->evWakeUp = wakeEvent;
    state = InterlockedCompareExchange(&pipeTI->state, PTI_STATE_STOP,
	    PTI_STATE_IDLE);
    switch (state) {
    case PTI_STATE_IDLE:
	/*
	 * Thread was idle/waiting, notify it goes teardown
	 */

    int state;

    if (!pipeTI) {
	return;
    }
    pipeTI = *pipeTIPtr;
    evControl = pipeTI->evControl;
    pipeTI->evWakeUp = NULL;

    /*
     * Try to sane stop the pipe worker, corresponding its current state
     */

    state = InterlockedCompareExchange(&pipeTI->state, PTI_STATE_STOP,
	    PTI_STATE_IDLE);

		}
	    }
	}
    }

    *pipeTIPtr = NULL;
    if (pipeTI) {
	if (pipeTI->evWakeUp) {
	    SetEvent(pipeTI->evWakeUp);
	}
	CloseHandle(pipeTI->evControl);
#ifndef _PTI_USE_CKALLOC
	free(pipeTI);
#else
	Tcl_Free(pipeTI);
#endif /* !_PTI_USE_CKALLOC */
    }

    if (!pipeTI) {
	return;
    }
    *pipeTIPtr = NULL;
    state = InterlockedExchange(&pipeTI->state, PTI_STATE_DOWN);
    if (state == PTI_STATE_STOP) {
	CloseHandle(pipeTI->evControl);
	if (pipeTI->evWakeUp) {
	    SetEvent(pipeTI->evWakeUp);
	}
#ifndef _PTI_USE_CKALLOC
	free(pipeTI);
#else
	Tcl_Free(pipeTI);
	/* be sure all subsystems used are finalized */
	Tcl_FinalizeThread();
#endif /* !_PTI_USE_CKALLOC */

	/*
	 * Initially the channel is writable and the writeThread is idle.
	 */

	infoPtr->osWrite.hEvent = CreateEventW(NULL, TRUE, FALSE, NULL);
	infoPtr->evWritable = CreateEventW(NULL, TRUE, TRUE, NULL);
	infoPtr->writeThread = CreateThread(NULL, 256, SerialWriterThread,
		TclPipeThreadCreateTI(&infoPtr->writeTI, infoPtr,
			infoPtr->evWritable), 0, NULL);
    }

    Tcl_SetChannelOption(NULL, infoPtr->channel, "-translation", "auto");

    return infoPtr->channel;
}