/* 
 * 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 1.1.2.7 1999/03/11 01:50:34 stanton Exp $
 * RCS: @(#) $Id: tclWinPipe.c,v 1.1.2.8 1999/03/14 18:55:11 stanton Exp $
 */

#include "tclWinInt.h"

#include <dos.h>
#include <fcntl.h>
#include <io.h>

	 * Clean up the background thread if necessary.  Note that this
	 * must be done before we can close the file, since the 
	 * thread may be blocking trying to read from the pipe.
	 */

	if (pipePtr->readThread) {
	    TerminateThread(pipePtr->readThread, 0);

	    /*
	     * Wait for the thread to terminate.  This ensures that we are
	     * completely cleaned up before we leave this function. 
	     */

	    WaitForSingleObject(pipePtr->readThread, INFINITE);
	    CloseHandle(pipePtr->readThread);
	    CloseHandle(pipePtr->readable);
	    CloseHandle(pipePtr->startReader);
	    pipePtr->readThread = NULL;
	}
	if (TclpCloseFile(pipePtr->readFile) != 0) {
	    errorCode = errno;

	 * terminate the thread and close the handles.  If the channel is
	 * nonblocking, there should be no pending write operations.
	 */

	if (pipePtr->writeThread) {
	    WaitForSingleObject(pipePtr->writable, INFINITE);
	    TerminateThread(pipePtr->writeThread, 0);
	    /*
	     * Wait for the thread to terminate.  This ensures that we are
	     * completely cleaned up before we leave this function. 
	     */

	    WaitForSingleObject(pipePtr->writeThread, INFINITE);
	    CloseHandle(pipePtr->writeThread);
	    CloseHandle(pipePtr->writable);
	    CloseHandle(pipePtr->startWriter);
	    pipePtr->writeThread = NULL;
	}
	if (TclpCloseFile(pipePtr->writeFile) != 0) {
	    if (errorCode == 0) {