/* 
 * tclWinPipe.c --
 *
 *	This file implements the Windows-specific exec pipeline functions,
 *	the "pipe" channel driver, and the "pid" Tcl command.
 *
 * Copyright (c) 1996-1997 by Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclWinPipe.c,v 1.53 2004/12/01 23:18:55 dgp Exp $
 * RCS: @(#) $Id: tclWinPipe.c,v 1.54 2005/01/27 00:23:34 andreas_kupries Exp $
 */

#include "tclWinInt.h"

#include <fcntl.h>
#include <io.h>
#include <sys/stat.h>

static void		PipeSetupProc(ClientData clientData, int flags);
static void		PipeWatchProc(ClientData instanceData, int mask);
static DWORD WINAPI	PipeWriterThread(LPVOID arg);
static void		ProcExitHandler(ClientData clientData);
static int		TempFileName(WCHAR name[MAX_PATH]);
static int		WaitForRead(PipeInfo *infoPtr, int blocking);

static void             PipeThreadActionProc _ANSI_ARGS_ ((
			   ClientData instanceData, int action));

/*
 * This structure describes the channel type structure for command pipe
 * based IO.
 */

static Tcl_ChannelType pipeChannelType = {
    "pipe",			/* Type name. */
    TCL_CHANNEL_VERSION_2,	/* v2 channel */
    TCL_CHANNEL_VERSION_4,	/* v4 channel */
    TCL_CLOSE2PROC,		/* Close proc. */
    PipeInputProc,		/* Input proc. */
    PipeOutputProc,		/* Output proc. */
    NULL,			/* Seek proc. */
    NULL,			/* Set option proc. */
    NULL,			/* Get option proc. */
    PipeWatchProc,		/* Set up notifier to watch the channel. */
    PipeGetHandleProc,		/* Get an OS handle from channel. */
    PipeClose2Proc,		/* close2proc */
    PipeBlockModeProc,		/* Set blocking or non-blocking mode.*/
    NULL,			/* flush proc. */
    NULL,			/* handler proc. */
    NULL,                       /* wide seek proc */
    PipeThreadActionProc,       /* thread action proc */
};

/*
 *----------------------------------------------------------------------
 *
 * PipeInit --
 *

    infoPtr->writeFile = writeFile;
    infoPtr->errorFile = errorFile;
    infoPtr->numPids = numPids;
    infoPtr->pidPtr = pidPtr;
    infoPtr->writeBuf = 0;
    infoPtr->writeBufLen = 0;
    infoPtr->writeError = 0;
    infoPtr->channel = (Tcl_Channel) NULL;

    /*
     * Use one of the fds associated with the channel as the
     * channel id.
     */

    if (readFile) {

	/*
	 * Alert the foreground thread.  Note that we need to treat this like
	 * a critical section so the foreground thread does not terminate
	 * this thread while we are holding a mutex in the notifier code.
	 */

	Tcl_MutexLock(&pipeMutex);
	if (infoPtr->threadId != NULL) {
	    /* TIP #218. When in flight ignore the event, no one will receive it anyway */
	Tcl_ThreadAlert(infoPtr->threadId);
	    Tcl_ThreadAlert(infoPtr->threadId);
	}
	Tcl_MutexUnlock(&pipeMutex);
    }

    return 0;
}

/*

	/*
	 * Alert the foreground thread.  Note that we need to treat this like
	 * a critical section so the foreground thread does not terminate
	 * this thread while we are holding a mutex in the notifier code.
	 */

	Tcl_MutexLock(&pipeMutex);
	if (infoPtr->threadId != NULL) {
	    /* TIP #218. When in flight ignore the event, no one will receive it anyway */
	Tcl_ThreadAlert(infoPtr->threadId);
	    Tcl_ThreadAlert(infoPtr->threadId);
	}
	Tcl_MutexUnlock(&pipeMutex);
    }

    return 0;
}


/*
 *----------------------------------------------------------------------
 *
 * PipeThreadActionProc --
 *
 *	Insert or remove any thread local refs to this channel.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Changes thread local list of valid channels.
 *
 *----------------------------------------------------------------------
 */

static void
PipeThreadActionProc (instanceData, action)
     ClientData instanceData;
     int action;
{
    PipeInfo *infoPtr = (PipeInfo *) instanceData;

    /* We do not access firstPipePtr in the thread structures. This is
     * not for all pipes managed by the thread, but only those we are
     * watching. Removal of the filevent handlers before transfer thus
     * takes care of this structure.
     */

    Tcl_MutexLock(&pipeMutex);
    if (action == TCL_CHANNEL_THREAD_INSERT) {
        /* We can't copy the thread information from the channel when
	 * the channel is created. At this time the channel back
	 * pointer has not been set yet. However in that case the
	 * threadId has already been set by TclpCreateCommandChannel
	 * itself, so the structure is still good.
	 */

        PipeInit ();
        if (infoPtr->channel != NULL) {
	    infoPtr->threadId = Tcl_GetChannelThread (infoPtr->channel);
	}
    } else {
	infoPtr->threadId = NULL;
    }
    Tcl_MutexUnlock(&pipeMutex);
}