/* 
 * 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 1.39 2003/12/24 04:18:23 davygrvy Exp $
 * RCS: @(#) $Id: tclWinPipe.c,v 1.40 2004/01/20 05:18:22 davygrvy Exp $
 */

#include "tclWinInt.h"

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

 */

unsigned long
TclpGetPid(
    Tcl_Pid pid)		/* The HANDLE of the child process. */
{
    ProcInfo *infoPtr;

    PipeInit();

    Tcl_MutexLock(&pipeMutex);
    for (infoPtr = procList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
	if (infoPtr->hProcess == (HANDLE) pid) {
	    Tcl_MutexUnlock(&pipeMutex);
	    return infoPtr->dwProcessId;
	}

Tcl_Pid
Tcl_WaitPid(
    Tcl_Pid pid,
    int *statPtr,
    int options)
{
    ProcInfo *infoPtr, **prevPtrPtr;
    ProcInfo *infoPtr = NULL, **prevPtrPtr;
    DWORD flags;
    Tcl_Pid result;
    DWORD ret, exitCode;

    PipeInit();

    /*
     * If no pid is specified, do nothing.
     */
    
    if (pid == 0) {
	*statPtr = 0;
	return 0;
    }

    /*
     * Find the process on the process list.
     * Find the process and cut it from the process list.
     */

    Tcl_MutexLock(&pipeMutex);
    prevPtrPtr = &procList;
    for (infoPtr = procList; infoPtr != NULL;
	    prevPtrPtr = &infoPtr->nextPtr, infoPtr = infoPtr->nextPtr) {
	 if (infoPtr->hProcess == (HANDLE) pid) {
	    *prevPtrPtr = infoPtr->nextPtr;
	    break;
	}
    }
    Tcl_MutexUnlock(&pipeMutex);

    /*
     * If the pid is not one of the processes we know about (we started it)

    } else {
	flags = INFINITE;
    }
    ret = WaitForSingleObject(infoPtr->hProcess, flags);
    if (ret == WAIT_TIMEOUT) {
	*statPtr = 0;
	if (options & WNOHANG) {
	    /*
	     * Re-insert this infoPtr back on the list.
	     */
	    Tcl_MutexLock(&pipeMutex);
	    infoPtr->nextPtr = procList;
	    procList = infoPtr;
	    Tcl_MutexUnlock(&pipeMutex);
	    return 0;
	} else {
	    result = 0;
	}
    } else if (ret == WAIT_OBJECT_0) {
	GetExitCodeProcess(infoPtr->hProcess, &exitCode);
	if (exitCode & 0xC0000000) {

    } else {
	errno = ECHILD;
        *statPtr = ECHILD;
	result = (Tcl_Pid) -1;
    }

    /*
     * Remove the process from the process list and close the process handle.
     * Officially close the process handle.
     */

    CloseHandle(infoPtr->hProcess);
    *prevPtrPtr = infoPtr->nextPtr;
    ckfree((char*)infoPtr);

    return result;
}

/*
 *----------------------------------------------------------------------