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Revision 67 - (show annotations) (download)
Mon Oct 31 00:57:34 2016 UTC (7 years, 4 months ago) by dashley
File MIME type: text/plain
File size: 13458 byte(s)
Header and footer cleanup.
1 /* $Header$ */
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 */

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