/*
 * tclUnixNotify.c --
 *
 *	This file contains the implementation of the select-based
 *	Unix-specific notifier, which is the lowest-level part of the
 *	Tcl event loop.  This file works together with
 *	../generic/tclNotify.c.
 *
 * Copyright (c) 1995-1997 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: tclUnixNotfy.c,v 1.5 1999/07/02 06:05:34 welch Exp $
 */

#include "tclInt.h"
#include "tclPort.h"
#include <signal.h> 

extern TclStubs tclStubs;

/*
 * This structure is used to keep track of the notifier info for a 
 * a registered file.
 */

typedef struct FileHandler {

    Tcl_Time *timePtr;		/* Timeout value, may be NULL. */
{
    /*
     * The interval timer doesn't do anything in this implementation,
     * because the only event loop is via Tcl_DoOneEvent, which passes
     * timeout values to Tcl_WaitForEvent.
     */

    if (tclStubs.tcl_SetTimer != Tcl_SetTimer) {
	tclStubs.tcl_SetTimer(timePtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ServiceModeHook --
 *

    Tcl_FileProc *proc;		/* Procedure to call for each
				 * selected event. */
    ClientData clientData;	/* Arbitrary data to pass to proc. */
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    FileHandler *filePtr;
    int index, bit;

    if (tclStubs.tcl_CreateFileHandler != Tcl_CreateFileHandler) {
	tclStubs.tcl_CreateFileHandler(fd, mask, proc, clientData);
	return;
    }

    for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL;
	 filePtr = filePtr->nextPtr) {
	if (filePtr->fd == fd) {
	    break;
	}
    }

Tcl_DeleteFileHandler(fd)
    int fd;		/* Stream id for which to remove callback procedure. */
{
    FileHandler *filePtr, *prevPtr;
    int index, bit, i;
    unsigned long flags;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (tclStubs.tcl_DeleteFileHandler != Tcl_DeleteFileHandler) {
	tclStubs.tcl_DeleteFileHandler(fd);
	return;
    }

    /*
     * Find the entry for the given file (and return if there isn't one).
     */

    for (prevPtr = NULL, filePtr = tsdPtr->firstFileHandlerPtr; ;
	 prevPtr = filePtr, filePtr = filePtr->nextPtr) {

    int bit, index, mask;
#ifdef TCL_THREADS
    int waitForFiles;
#else
    int numFound;
#endif
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (tclStubs.tcl_WaitForEvent != Tcl_WaitForEvent) {
	return tclStubs.tcl_WaitForEvent(timePtr);
    }

    /*
     * Set up the timeout structure.  Note that if there are no events to
     * check for, we return with a negative result rather than blocking
     * forever.
     */