src/c_tcl_base_7_5_w_mods/tclwinnotify.c

/* $Header$ */
/* 
 * tclWinNotify.c --
 *
 *      This file contains Windows-specific procedures for the 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: tclwinnotify.c,v 1.1.1.1 2001/06/13 04:49:27 dtashley Exp $
 */

#include "tclWinInt.h"
#include <winsock.h>

/*
 * The follwing static indicates whether this module has been initialized.
 */

static int initialized = 0;

#define INTERVAL_TIMER 1        /* Handle of interval timer. */

#define WM_WAKEUP WM_USER       /* Message that is send by
                                 * Tcl_AlertNotifier. */
/*
 * The following static structure contains the state information for the
 * Windows implementation of the Tcl notifier.  One of these structures
 * is created for each thread that is using the notifier.  
 */

typedef struct ThreadSpecificData {
    CRITICAL_SECTION crit;      /* Monitor for this notifier. */
    DWORD thread;               /* Identifier for thread associated with this
                                 * notifier. */
    HANDLE event;               /* Event object used to wake up the notifier
                                 * thread. */
    int pending;                /* Alert message pending, this field is
                                 * locked by the notifierMutex. */
    HWND hwnd;                  /* Messaging window. */
    int timeout;                /* Current timeout value. */
    int timerActive;            /* 1 if interval timer is running. */
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

extern TclStubs tclStubs;
/*
 * The following static indicates the number of threads that have
 * initialized notifiers.  It controls the lifetime of the TclNotifier
 * window class.
 *
 * You must hold the notifierMutex lock before accessing this variable.
 */

static int notifierCount = 0;
TCL_DECLARE_MUTEX(notifierMutex)

/*
 * Static routines defined in this file.
 */

static LRESULT CALLBACK NotifierProc(HWND hwnd, UINT message,
                            WPARAM wParam, LPARAM lParam);


/*
 *----------------------------------------------------------------------
 *
 * Tcl_InitNotifier --
 *
 *      Initializes the platform specific notifier state.
 *
 * Results:
 *      Returns a handle to the notifier state for this thread..
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

ClientData
Tcl_InitNotifier()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    WNDCLASS class;

    /*
     * Register Notifier window class if this is the first thread to
     * use this module.
     */

    Tcl_MutexLock(&notifierMutex);
    if (notifierCount == 0) {
        class.style = 0;
        class.cbClsExtra = 0;
        class.cbWndExtra = 0;
        class.hInstance = TclWinGetTclInstance();
        class.hbrBackground = NULL;
        class.lpszMenuName = NULL;
        class.lpszClassName = "TclNotifier";
        class.lpfnWndProc = NotifierProc;
        class.hIcon = NULL;
        class.hCursor = NULL;

        if (!RegisterClassA(&class)) {
            panic("Unable to register TclNotifier window class");
        }
    }
    notifierCount++;
    Tcl_MutexUnlock(&notifierMutex);

    tsdPtr->pending = 0;
    tsdPtr->timerActive = 0;

    InitializeCriticalSection(&tsdPtr->crit);

    tsdPtr->hwnd = NULL;
    tsdPtr->thread = GetCurrentThreadId();
    tsdPtr->event = CreateEvent(NULL, TRUE /* manual */,
            FALSE /* !signaled */, NULL);

    return (ClientData) tsdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FinalizeNotifier --
 *
 *      This function is called to cleanup the notifier state before
 *      a thread is terminated.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      May dispose of the notifier window and class.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_FinalizeNotifier(clientData)
    ClientData clientData;      /* Pointer to notifier data. */
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData;

    DeleteCriticalSection(&tsdPtr->crit);
    CloseHandle(tsdPtr->event);

    /*
     * Clean up the timer and messaging window for this thread.
     */

    if (tsdPtr->hwnd) {
        KillTimer(tsdPtr->hwnd, INTERVAL_TIMER);
        DestroyWindow(tsdPtr->hwnd);
    }

    /*
     * If this is the last thread to use the notifier, unregister
     * the notifier window class.
     */

    Tcl_MutexLock(&notifierMutex);
    notifierCount--;
    if (notifierCount == 0) {
        UnregisterClassA("TclNotifier", TclWinGetTclInstance());
    }
    Tcl_MutexUnlock(&notifierMutex);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AlertNotifier --
 *
 *      Wake up the specified notifier from any thread. This routine
 *      is called by the platform independent notifier code whenever
 *      the Tcl_ThreadAlert routine is called.  This routine is
 *      guaranteed not to be called on a given notifier after
 *      Tcl_FinalizeNotifier is called for that notifier.  This routine
 *      is typically called from a thread other than the notifier's
 *      thread.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Sends a message to the messaging window for the notifier
 *      if there isn't already one pending.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AlertNotifier(clientData)
    ClientData clientData;      /* Pointer to thread data. */
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData;

    /*
     * Note that we do not need to lock around access to the hwnd
     * because the race condition has no effect since any race condition
     * implies that the notifier thread is already awake.
     */

    if (tsdPtr->hwnd) {
        /*
         * We do need to lock around access to the pending flag.
         */

        EnterCriticalSection(&tsdPtr->crit);
        if (!tsdPtr->pending) {
            PostMessage(tsdPtr->hwnd, WM_WAKEUP, 0, 0);
        }
        tsdPtr->pending = 1;
        LeaveCriticalSection(&tsdPtr->crit);
    } else {
        SetEvent(tsdPtr->event);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetTimer --
 *
 *      This procedure sets the current notifier timer value.  The
 *      notifier will ensure that Tcl_ServiceAll() is called after
 *      the specified interval, even if no events have occurred.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Replaces any previous timer.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetTimer(
    Tcl_Time *timePtr)          /* Maximum block time, or NULL. */
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    UINT timeout;

    /*
     * Allow the notifier to be hooked.  This may not make sense
     * on Windows, but mirrors the UNIX hook.
     */

    if (tclStubs.tcl_SetTimer != Tcl_SetTimer) {
        tclStubs.tcl_SetTimer(timePtr);
        return;
    }

    /*
     * We only need to set up an interval timer if we're being called
     * from an external event loop.  If we don't have a window handle
     * then we just return immediately and let Tcl_WaitForEvent handle
     * timeouts.
     */

    if (!tsdPtr->hwnd) {
        return;
    }

    if (!timePtr) {
        timeout = 0;
    } else {
        /*
         * Make sure we pass a non-zero value into the timeout argument.
         * Windows seems to get confused by zero length timers.
         */

        timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
        if (timeout == 0) {
            timeout = 1;
        }
    }
    tsdPtr->timeout = timeout;
    if (timeout != 0) {
        tsdPtr->timerActive = 1;
        SetTimer(tsdPtr->hwnd, INTERVAL_TIMER,
                    (unsigned long) tsdPtr->timeout, NULL);
    } else {
        tsdPtr->timerActive = 0;
        KillTimer(tsdPtr->hwnd, INTERVAL_TIMER);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ServiceModeHook --
 *
 *      This function is invoked whenever the service mode changes.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      If this is the first time the notifier is set into
 *      TCL_SERVICE_ALL, then the communication window is created.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_ServiceModeHook(mode)
    int mode;                   /* Either TCL_SERVICE_ALL, or
                                 * TCL_SERVICE_NONE. */
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    /*
     * If this is the first time that the notifier has been used from a
     * modal loop, then create a communication window.  Note that after
     * this point, the application needs to service events in a timely
     * fashion or Windows will hang waiting for the window to respond
     * to synchronous system messages.  At some point, we may want to
     * consider destroying the window if we leave the modal loop, but
     * for now we'll leave it around.
     */

    if (mode == TCL_SERVICE_ALL && !tsdPtr->hwnd) {
        tsdPtr->hwnd = CreateWindowA("TclNotifier", "TclNotifier", WS_TILED,
                0, 0, 0, 0, NULL, NULL, TclWinGetTclInstance(), NULL);
        /*
         * Send an initial message to the window to ensure that we wake up the
         * notifier once we get into the modal loop.  This will force the
         * notifier to recompute the timeout value and schedule a timer
         * if one is needed.
         */

        Tcl_AlertNotifier((ClientData)tsdPtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * NotifierProc --
 *
 *      This procedure is invoked by Windows to process events on
 *      the notifier window.  Messages will be sent to this window
 *      in response to external timer events or calls to
 *      TclpAlertTsdPtr->
 *
 * Results:
 *      A standard windows result.
 *
 * Side effects:
 *      Services any pending events.
 *
 *----------------------------------------------------------------------
 */

static LRESULT CALLBACK
NotifierProc(
    HWND hwnd,
    UINT message,
    WPARAM wParam,
    LPARAM lParam)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (message == WM_WAKEUP) {
        EnterCriticalSection(&tsdPtr->crit);
        tsdPtr->pending = 0;
        LeaveCriticalSection(&tsdPtr->crit);
    } else if (message != WM_TIMER) {
        return DefWindowProc(hwnd, message, wParam, lParam);
    }
        
    /*
     * Process all of the runnable events.
     */

    Tcl_ServiceAll();
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_WaitForEvent --
 *
 *      This function is called by Tcl_DoOneEvent to wait for new
 *      events on the message queue.  If the block time is 0, then
 *      Tcl_WaitForEvent just polls the event queue without blocking.
 *
 * Results:
 *      Returns -1 if a WM_QUIT message is detected, returns 1 if
 *      a message was dispatched, otherwise returns 0.
 *
 * Side effects:
 *      Dispatches a message to a window procedure, which could do
 *      anything.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_WaitForEvent(
    Tcl_Time *timePtr)          /* Maximum block time, or NULL. */
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    MSG msg;
    DWORD timeout, result;
    int status;

    /*
     * Allow the notifier to be hooked.  This may not make
     * sense on windows, but mirrors the UNIX hook.
     */

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

    /*
     * Compute the timeout in milliseconds.
     */

    if (timePtr) {
        timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
    } else {
        timeout = INFINITE;
    }

    /*
     * Check to see if there are any messages in the queue before waiting
     * because MsgWaitForMultipleObjects will not wake up if there are events
     * currently sitting in the queue.
     */

    if (!PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
        /*
         * Wait for something to happen (a signal from another thread, a
         * message, or timeout).
         */

        result = MsgWaitForMultipleObjects(1, &tsdPtr->event, FALSE, timeout,
                QS_ALLINPUT);
    }

    /*
     * Check to see if there are any messages to process.
     */

    if (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
        /*
         * Retrieve and dispatch the first message.
         */

        result = GetMessage(&msg, NULL, 0, 0);
        if (result == 0) {
            /*
             * We received a request to exit this thread (WM_QUIT), so
             * propagate the quit message and start unwinding.
             */

            PostQuitMessage(msg.wParam);
            status = -1;
        } else if (result == -1) {
            /*
             * We got an error from the system.  I have no idea why this would
             * happen, so we'll just unwind.
             */

            status = -1;
        } else {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
            status = 1;
        }
    } else {
        status = 0;
    }

    ResetEvent(tsdPtr->event);
    return status;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_Sleep --
 *
 *      Delay execution for the specified number of milliseconds.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Time passes.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_Sleep(ms)
    int ms;                     /* Number of milliseconds to sleep. */
{
    Sleep(ms);
}

/* End of tclwinnotify.c */
1	dashley	71	/* $Header$ */
2			/*
3			* tclWinNotify.c --
4			*
5			* This file contains Windows-specific procedures for the notifier,
6			* which is the lowest-level part of the Tcl event loop. This file
7			* works together with ../generic/tclNotify.c.
8			*
9			* Copyright (c) 1995-1997 Sun Microsystems, Inc.
10			*
11			* See the file "license.terms" for information on usage and redistribution
12			* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
13			*
14			* RCS: @(#) $Id: tclwinnotify.c,v 1.1.1.1 2001/06/13 04:49:27 dtashley Exp $
15			*/
16
17			#include "tclWinInt.h"
18			#include <winsock.h>
19
20			/*
21			* The follwing static indicates whether this module has been initialized.
22			*/
23
24			static int initialized = 0;
25
26			#define INTERVAL_TIMER 1 /* Handle of interval timer. */
27
28			#define WM_WAKEUP WM_USER /* Message that is send by
29			* Tcl_AlertNotifier. */
30			/*
31			* The following static structure contains the state information for the
32			* Windows implementation of the Tcl notifier. One of these structures
33			* is created for each thread that is using the notifier.
34			*/
35
36			typedef struct ThreadSpecificData {
37			CRITICAL_SECTION crit; /* Monitor for this notifier. */
38			DWORD thread; /* Identifier for thread associated with this
39			* notifier. */
40			HANDLE event; /* Event object used to wake up the notifier
41			* thread. */
42			int pending; /* Alert message pending, this field is
43			* locked by the notifierMutex. */
44			HWND hwnd; /* Messaging window. */
45			int timeout; /* Current timeout value. */
46			int timerActive; /* 1 if interval timer is running. */
47			} ThreadSpecificData;
48
49			static Tcl_ThreadDataKey dataKey;
50
51			extern TclStubs tclStubs;
52			/*
53			* The following static indicates the number of threads that have
54			* initialized notifiers. It controls the lifetime of the TclNotifier
55			* window class.
56			*
57			* You must hold the notifierMutex lock before accessing this variable.
58			*/
59
60			static int notifierCount = 0;
61			TCL_DECLARE_MUTEX(notifierMutex)
62
63			/*
64			* Static routines defined in this file.
65			*/
66
67			static LRESULT CALLBACK NotifierProc(HWND hwnd, UINT message,
68			WPARAM wParam, LPARAM lParam);
69
70
71			/*
72			*----------------------------------------------------------------------
73			*
74			* Tcl_InitNotifier --
75			*
76			* Initializes the platform specific notifier state.
77			*
78			* Results:
79			* Returns a handle to the notifier state for this thread..
80			*
81			* Side effects:
82			* None.
83			*
84			*----------------------------------------------------------------------
85			*/
86
87			ClientData
88			Tcl_InitNotifier()
89			{
90			ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
91			WNDCLASS class;
92
93			/*
94			* Register Notifier window class if this is the first thread to
95			* use this module.
96			*/
97
98			Tcl_MutexLock(&notifierMutex);
99			if (notifierCount == 0) {
100			class.style = 0;
101			class.cbClsExtra = 0;
102			class.cbWndExtra = 0;
103			class.hInstance = TclWinGetTclInstance();
104			class.hbrBackground = NULL;
105			class.lpszMenuName = NULL;
106			class.lpszClassName = "TclNotifier";
107			class.lpfnWndProc = NotifierProc;
108			class.hIcon = NULL;
109			class.hCursor = NULL;
110
111			if (!RegisterClassA(&class)) {
112			panic("Unable to register TclNotifier window class");
113			}
114			}
115			notifierCount++;
116			Tcl_MutexUnlock(&notifierMutex);
117
118			tsdPtr->pending = 0;
119			tsdPtr->timerActive = 0;
120
121			InitializeCriticalSection(&tsdPtr->crit);
122
123			tsdPtr->hwnd = NULL;
124			tsdPtr->thread = GetCurrentThreadId();
125			tsdPtr->event = CreateEvent(NULL, TRUE /* manual */,
126			FALSE /* !signaled */, NULL);
127
128			return (ClientData) tsdPtr;
129			}
130
131			/*
132			*----------------------------------------------------------------------
133			*
134			* Tcl_FinalizeNotifier --
135			*
136			* This function is called to cleanup the notifier state before
137			* a thread is terminated.
138			*
139			* Results:
140			* None.
141			*
142			* Side effects:
143			* May dispose of the notifier window and class.
144			*
145			*----------------------------------------------------------------------
146			*/
147
148			void
149			Tcl_FinalizeNotifier(clientData)
150			ClientData clientData; /* Pointer to notifier data. */
151			{
152			ThreadSpecificData tsdPtr = (ThreadSpecificData ) clientData;
153
154			DeleteCriticalSection(&tsdPtr->crit);
155			CloseHandle(tsdPtr->event);
156
157			/*
158			* Clean up the timer and messaging window for this thread.
159			*/
160
161			if (tsdPtr->hwnd) {
162			KillTimer(tsdPtr->hwnd, INTERVAL_TIMER);
163			DestroyWindow(tsdPtr->hwnd);
164			}
165
166			/*
167			* If this is the last thread to use the notifier, unregister
168			* the notifier window class.
169			*/
170
171			Tcl_MutexLock(&notifierMutex);
172			notifierCount--;
173			if (notifierCount == 0) {
174			UnregisterClassA("TclNotifier", TclWinGetTclInstance());
175			}
176			Tcl_MutexUnlock(&notifierMutex);
177			}
178
179			/*
180			*----------------------------------------------------------------------
181			*
182			* Tcl_AlertNotifier --
183			*
184			* Wake up the specified notifier from any thread. This routine
185			* is called by the platform independent notifier code whenever
186			* the Tcl_ThreadAlert routine is called. This routine is
187			* guaranteed not to be called on a given notifier after
188			* Tcl_FinalizeNotifier is called for that notifier. This routine
189			* is typically called from a thread other than the notifier's
190			* thread.
191			*
192			* Results:
193			* None.
194			*
195			* Side effects:
196			* Sends a message to the messaging window for the notifier
197			* if there isn't already one pending.
198			*
199			*----------------------------------------------------------------------
200			*/
201
202			void
203			Tcl_AlertNotifier(clientData)
204			ClientData clientData; /* Pointer to thread data. */
205			{
206			ThreadSpecificData tsdPtr = (ThreadSpecificData ) clientData;
207
208			/*
209			* Note that we do not need to lock around access to the hwnd
210			* because the race condition has no effect since any race condition
211			* implies that the notifier thread is already awake.
212			*/
213
214			if (tsdPtr->hwnd) {
215			/*
216			* We do need to lock around access to the pending flag.
217			*/
218
219			EnterCriticalSection(&tsdPtr->crit);
220			if (!tsdPtr->pending) {
221			PostMessage(tsdPtr->hwnd, WM_WAKEUP, 0, 0);
222			}
223			tsdPtr->pending = 1;
224			LeaveCriticalSection(&tsdPtr->crit);
225			} else {
226			SetEvent(tsdPtr->event);
227			}
228			}
229
230			/*
231			*----------------------------------------------------------------------
232			*
233			* Tcl_SetTimer --
234			*
235			* This procedure sets the current notifier timer value. The
236			* notifier will ensure that Tcl_ServiceAll() is called after
237			* the specified interval, even if no events have occurred.
238			*
239			* Results:
240			* None.
241			*
242			* Side effects:
243			* Replaces any previous timer.
244			*
245			*----------------------------------------------------------------------
246			*/
247
248			void
249			Tcl_SetTimer(
250			Tcl_Time timePtr) / Maximum block time, or NULL. */
251			{
252			ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
253			UINT timeout;
254
255			/*
256			* Allow the notifier to be hooked. This may not make sense
257			* on Windows, but mirrors the UNIX hook.
258			*/
259
260			if (tclStubs.tcl_SetTimer != Tcl_SetTimer) {
261			tclStubs.tcl_SetTimer(timePtr);
262			return;
263			}
264
265			/*
266			* We only need to set up an interval timer if we're being called
267			* from an external event loop. If we don't have a window handle
268			* then we just return immediately and let Tcl_WaitForEvent handle
269			* timeouts.
270			*/
271
272			if (!tsdPtr->hwnd) {
273			return;
274			}
275
276			if (!timePtr) {
277			timeout = 0;
278			} else {
279			/*
280			* Make sure we pass a non-zero value into the timeout argument.
281			* Windows seems to get confused by zero length timers.
282			*/
283
284			timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
285			if (timeout == 0) {
286			timeout = 1;
287			}
288			}
289			tsdPtr->timeout = timeout;
290			if (timeout != 0) {
291			tsdPtr->timerActive = 1;
292			SetTimer(tsdPtr->hwnd, INTERVAL_TIMER,
293			(unsigned long) tsdPtr->timeout, NULL);
294			} else {
295			tsdPtr->timerActive = 0;
296			KillTimer(tsdPtr->hwnd, INTERVAL_TIMER);
297			}
298			}
299
300			/*
301			*----------------------------------------------------------------------
302			*
303			* Tcl_ServiceModeHook --
304			*
305			* This function is invoked whenever the service mode changes.
306			*
307			* Results:
308			* None.
309			*
310			* Side effects:
311			* If this is the first time the notifier is set into
312			* TCL_SERVICE_ALL, then the communication window is created.
313			*
314			*----------------------------------------------------------------------
315			*/
316
317			void
318			Tcl_ServiceModeHook(mode)
319			int mode; /* Either TCL_SERVICE_ALL, or
320			* TCL_SERVICE_NONE. */
321			{
322			ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
323
324			/*
325			* If this is the first time that the notifier has been used from a
326			* modal loop, then create a communication window. Note that after
327			* this point, the application needs to service events in a timely
328			* fashion or Windows will hang waiting for the window to respond
329			* to synchronous system messages. At some point, we may want to
330			* consider destroying the window if we leave the modal loop, but
331			* for now we'll leave it around.
332			*/
333
334			if (mode == TCL_SERVICE_ALL && !tsdPtr->hwnd) {
335			tsdPtr->hwnd = CreateWindowA("TclNotifier", "TclNotifier", WS_TILED,
336			0, 0, 0, 0, NULL, NULL, TclWinGetTclInstance(), NULL);
337			/*
338			* Send an initial message to the window to ensure that we wake up the
339			* notifier once we get into the modal loop. This will force the
340			* notifier to recompute the timeout value and schedule a timer
341			* if one is needed.
342			*/
343
344			Tcl_AlertNotifier((ClientData)tsdPtr);
345			}
346			}
347
348			/*
349			*----------------------------------------------------------------------
350			*
351			* NotifierProc --
352			*
353			* This procedure is invoked by Windows to process events on
354			* the notifier window. Messages will be sent to this window
355			* in response to external timer events or calls to
356			* TclpAlertTsdPtr->
357			*
358			* Results:
359			* A standard windows result.
360			*
361			* Side effects:
362			* Services any pending events.
363			*
364			*----------------------------------------------------------------------
365			*/
366
367			static LRESULT CALLBACK
368			NotifierProc(
369			HWND hwnd,
370			UINT message,
371			WPARAM wParam,
372			LPARAM lParam)
373			{
374			ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
375
376			if (message == WM_WAKEUP) {
377			EnterCriticalSection(&tsdPtr->crit);
378			tsdPtr->pending = 0;
379			LeaveCriticalSection(&tsdPtr->crit);
380			} else if (message != WM_TIMER) {
381			return DefWindowProc(hwnd, message, wParam, lParam);
382			}
383
384			/*
385			* Process all of the runnable events.
386			*/
387
388			Tcl_ServiceAll();
389			return 0;
390			}
391
392			/*
393			*----------------------------------------------------------------------
394			*
395			* Tcl_WaitForEvent --
396			*
397			* This function is called by Tcl_DoOneEvent to wait for new
398			* events on the message queue. If the block time is 0, then
399			* Tcl_WaitForEvent just polls the event queue without blocking.
400			*
401			* Results:
402			* Returns -1 if a WM_QUIT message is detected, returns 1 if
403			* a message was dispatched, otherwise returns 0.
404			*
405			* Side effects:
406			* Dispatches a message to a window procedure, which could do
407			* anything.
408			*
409			*----------------------------------------------------------------------
410			*/
411
412			int
413			Tcl_WaitForEvent(
414			Tcl_Time timePtr) / Maximum block time, or NULL. */
415			{
416			ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
417			MSG msg;
418			DWORD timeout, result;
419			int status;
420
421			/*
422			* Allow the notifier to be hooked. This may not make
423			* sense on windows, but mirrors the UNIX hook.
424			*/
425
426			if (tclStubs.tcl_WaitForEvent != Tcl_WaitForEvent) {
427			return tclStubs.tcl_WaitForEvent(timePtr);
428			}
429
430			/*
431			* Compute the timeout in milliseconds.
432			*/
433
434			if (timePtr) {
435			timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
436			} else {
437			timeout = INFINITE;
438			}
439
440			/*
441			* Check to see if there are any messages in the queue before waiting
442			* because MsgWaitForMultipleObjects will not wake up if there are events
443			* currently sitting in the queue.
444			*/
445
446			if (!PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
447			/*
448			* Wait for something to happen (a signal from another thread, a
449			* message, or timeout).
450			*/
451
452			result = MsgWaitForMultipleObjects(1, &tsdPtr->event, FALSE, timeout,
453			QS_ALLINPUT);
454			}
455
456			/*
457			* Check to see if there are any messages to process.
458			*/
459
460			if (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
461			/*
462			* Retrieve and dispatch the first message.
463			*/
464
465			result = GetMessage(&msg, NULL, 0, 0);
466			if (result == 0) {
467			/*
468			* We received a request to exit this thread (WM_QUIT), so
469			* propagate the quit message and start unwinding.
470			*/
471
472			PostQuitMessage(msg.wParam);
473			status = -1;
474			} else if (result == -1) {
475			/*
476			* We got an error from the system. I have no idea why this would
477			* happen, so we'll just unwind.
478			*/
479
480			status = -1;
481			} else {
482			TranslateMessage(&msg);
483			DispatchMessage(&msg);
484			status = 1;
485			}
486			} else {
487			status = 0;
488			}
489
490			ResetEvent(tsdPtr->event);
491			return status;
492			}
493
494			/*
495			*----------------------------------------------------------------------
496			*
497			* Tcl_Sleep --
498			*
499			* Delay execution for the specified number of milliseconds.
500			*
501			* Results:
502			* None.
503			*
504			* Side effects:
505			* Time passes.
506			*
507			*----------------------------------------------------------------------
508			*/
509
510			void
511			Tcl_Sleep(ms)
512			int ms; /* Number of milliseconds to sleep. */
513			{
514			Sleep(ms);
515			}
516
517			/* End of tclwinnotify.c */