1 |
/* $Header$ */
|
2 |
/*
|
3 |
* tclWinThread.c --
|
4 |
*
|
5 |
* This file implements the Windows-specific thread operations.
|
6 |
*
|
7 |
* Copyright (c) 1998 by Sun Microsystems, Inc.
|
8 |
* Copyright (c) 1999 by Scriptics Corporation
|
9 |
*
|
10 |
* See the file "license.terms" for information on usage and redistribution
|
11 |
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
12 |
*
|
13 |
* RCS: @(#) $Id: tclwinthrd.c,v 1.1.1.1 2001/06/13 04:50:42 dtashley Exp $
|
14 |
*/
|
15 |
|
16 |
#include "tclWinInt.h"
|
17 |
|
18 |
#include <dos.h>
|
19 |
#include <fcntl.h>
|
20 |
#include <io.h>
|
21 |
#include <sys/stat.h>
|
22 |
|
23 |
/*
|
24 |
* This is the master lock used to serialize access to other
|
25 |
* serialization data structures.
|
26 |
*/
|
27 |
|
28 |
static CRITICAL_SECTION masterLock;
|
29 |
static int init = 0;
|
30 |
#define MASTER_LOCK EnterCriticalSection(&masterLock)
|
31 |
#define MASTER_UNLOCK LeaveCriticalSection(&masterLock)
|
32 |
|
33 |
/*
|
34 |
* This is the master lock used to serialize initialization and finalization
|
35 |
* of Tcl as a whole.
|
36 |
*/
|
37 |
|
38 |
static CRITICAL_SECTION initLock;
|
39 |
|
40 |
/*
|
41 |
* allocLock is used by Tcl's version of malloc for synchronization.
|
42 |
* For obvious reasons, cannot use any dyamically allocated storage.
|
43 |
*/
|
44 |
|
45 |
static CRITICAL_SECTION allocLock;
|
46 |
static Tcl_Mutex allocLockPtr = (Tcl_Mutex) &allocLock;
|
47 |
|
48 |
/*
|
49 |
* Condition variables are implemented with a combination of a
|
50 |
* per-thread Windows Event and a per-condition waiting queue.
|
51 |
* The idea is that each thread has its own Event that it waits
|
52 |
* on when it is doing a ConditionWait; it uses the same event for
|
53 |
* all condition variables because it only waits on one at a time.
|
54 |
* Each condition variable has a queue of waiting threads, and a
|
55 |
* mutex used to serialize access to this queue.
|
56 |
*
|
57 |
* Special thanks to David Nichols and
|
58 |
* Jim Davidson for advice on the Condition Variable implementation.
|
59 |
*/
|
60 |
|
61 |
/*
|
62 |
* The per-thread event and queue pointers.
|
63 |
*/
|
64 |
|
65 |
typedef struct ThreadSpecificData {
|
66 |
HANDLE condEvent; /* Per-thread condition event */
|
67 |
struct ThreadSpecificData *nextPtr; /* Queue pointers */
|
68 |
struct ThreadSpecificData *prevPtr;
|
69 |
int flags; /* See flags below */
|
70 |
} ThreadSpecificData;
|
71 |
static Tcl_ThreadDataKey dataKey;
|
72 |
|
73 |
/*
|
74 |
* State bits for the thread.
|
75 |
* WIN_THREAD_UNINIT Uninitialized. Must be zero because
|
76 |
* of the way ThreadSpecificData is created.
|
77 |
* WIN_THREAD_RUNNING Running, not waiting.
|
78 |
* WIN_THREAD_BLOCKED Waiting, or trying to wait.
|
79 |
* WIN_THREAD_DEAD Dying - no per-thread event anymore.
|
80 |
*/
|
81 |
|
82 |
#define WIN_THREAD_UNINIT 0x0
|
83 |
#define WIN_THREAD_RUNNING 0x1
|
84 |
#define WIN_THREAD_BLOCKED 0x2
|
85 |
#define WIN_THREAD_DEAD 0x4
|
86 |
|
87 |
/*
|
88 |
* The per condition queue pointers and the
|
89 |
* Mutex used to serialize access to the queue.
|
90 |
*/
|
91 |
|
92 |
typedef struct WinCondition {
|
93 |
CRITICAL_SECTION condLock; /* Lock to serialize queuing on the condition */
|
94 |
struct ThreadSpecificData *firstPtr; /* Queue pointers */
|
95 |
struct ThreadSpecificData *lastPtr;
|
96 |
} WinCondition;
|
97 |
|
98 |
static void FinalizeConditionEvent(ClientData data);
|
99 |
|
100 |
|
101 |
/*
|
102 |
*----------------------------------------------------------------------
|
103 |
*
|
104 |
* Tcl_CreateThread --
|
105 |
*
|
106 |
* This procedure creates a new thread.
|
107 |
*
|
108 |
* Results:
|
109 |
* TCL_OK if the thread could be created. The thread ID is
|
110 |
* returned in a parameter.
|
111 |
*
|
112 |
* Side effects:
|
113 |
* A new thread is created.
|
114 |
*
|
115 |
*----------------------------------------------------------------------
|
116 |
*/
|
117 |
|
118 |
int
|
119 |
Tcl_CreateThread(idPtr, proc, clientData, stackSize, flags)
|
120 |
Tcl_ThreadId *idPtr; /* Return, the ID of the thread */
|
121 |
Tcl_ThreadCreateProc proc; /* Main() function of the thread */
|
122 |
ClientData clientData; /* The one argument to Main() */
|
123 |
int stackSize; /* Size of stack for the new thread */
|
124 |
int flags; /* Flags controlling behaviour of
|
125 |
* the new thread */
|
126 |
{
|
127 |
unsigned long code;
|
128 |
|
129 |
code = _beginthreadex(NULL, stackSize, proc, clientData, 0,
|
130 |
(unsigned *)idPtr);
|
131 |
if (code == 0) {
|
132 |
return TCL_ERROR;
|
133 |
} else {
|
134 |
return TCL_OK;
|
135 |
}
|
136 |
}
|
137 |
|
138 |
/*
|
139 |
*----------------------------------------------------------------------
|
140 |
*
|
141 |
* TclpThreadExit --
|
142 |
*
|
143 |
* This procedure terminates the current thread.
|
144 |
*
|
145 |
* Results:
|
146 |
* None.
|
147 |
*
|
148 |
* Side effects:
|
149 |
* This procedure terminates the current thread.
|
150 |
*
|
151 |
*----------------------------------------------------------------------
|
152 |
*/
|
153 |
|
154 |
void
|
155 |
TclpThreadExit(status)
|
156 |
int status;
|
157 |
{
|
158 |
_endthreadex((DWORD)status);
|
159 |
}
|
160 |
|
161 |
|
162 |
/*
|
163 |
*----------------------------------------------------------------------
|
164 |
*
|
165 |
* Tcl_GetCurrentThread --
|
166 |
*
|
167 |
* This procedure returns the ID of the currently running thread.
|
168 |
*
|
169 |
* Results:
|
170 |
* A thread ID.
|
171 |
*
|
172 |
* Side effects:
|
173 |
* None.
|
174 |
*
|
175 |
*----------------------------------------------------------------------
|
176 |
*/
|
177 |
|
178 |
Tcl_ThreadId
|
179 |
Tcl_GetCurrentThread()
|
180 |
{
|
181 |
return (Tcl_ThreadId)GetCurrentThreadId();
|
182 |
}
|
183 |
|
184 |
|
185 |
/*
|
186 |
*----------------------------------------------------------------------
|
187 |
*
|
188 |
* TclpInitLock
|
189 |
*
|
190 |
* This procedure is used to grab a lock that serializes initialization
|
191 |
* and finalization of Tcl. On some platforms this may also initialize
|
192 |
* the mutex used to serialize creation of more mutexes and thread
|
193 |
* local storage keys.
|
194 |
*
|
195 |
* Results:
|
196 |
* None.
|
197 |
*
|
198 |
* Side effects:
|
199 |
* Acquire the initialization mutex.
|
200 |
*
|
201 |
*----------------------------------------------------------------------
|
202 |
*/
|
203 |
|
204 |
void
|
205 |
TclpInitLock()
|
206 |
{
|
207 |
if (!init) {
|
208 |
/*
|
209 |
* There is a fundamental race here that is solved by creating
|
210 |
* the first Tcl interpreter in a single threaded environment.
|
211 |
* Once the interpreter has been created, it is safe to create
|
212 |
* more threads that create interpreters in parallel.
|
213 |
*/
|
214 |
init = 1;
|
215 |
InitializeCriticalSection(&initLock);
|
216 |
InitializeCriticalSection(&masterLock);
|
217 |
}
|
218 |
EnterCriticalSection(&initLock);
|
219 |
}
|
220 |
|
221 |
|
222 |
/*
|
223 |
*----------------------------------------------------------------------
|
224 |
*
|
225 |
* TclpInitUnlock
|
226 |
*
|
227 |
* This procedure is used to release a lock that serializes initialization
|
228 |
* and finalization of Tcl.
|
229 |
*
|
230 |
* Results:
|
231 |
* None.
|
232 |
*
|
233 |
* Side effects:
|
234 |
* Release the initialization mutex.
|
235 |
*
|
236 |
*----------------------------------------------------------------------
|
237 |
*/
|
238 |
|
239 |
void
|
240 |
TclpInitUnlock()
|
241 |
{
|
242 |
LeaveCriticalSection(&initLock);
|
243 |
}
|
244 |
|
245 |
|
246 |
/*
|
247 |
*----------------------------------------------------------------------
|
248 |
*
|
249 |
* TclpMasterLock
|
250 |
*
|
251 |
* This procedure is used to grab a lock that serializes creation
|
252 |
* of mutexes, condition variables, and thread local storage keys.
|
253 |
*
|
254 |
* This lock must be different than the initLock because the
|
255 |
* initLock is held during creation of syncronization objects.
|
256 |
*
|
257 |
* Results:
|
258 |
* None.
|
259 |
*
|
260 |
* Side effects:
|
261 |
* Acquire the master mutex.
|
262 |
*
|
263 |
*----------------------------------------------------------------------
|
264 |
*/
|
265 |
|
266 |
void
|
267 |
TclpMasterLock()
|
268 |
{
|
269 |
if (!init) {
|
270 |
/*
|
271 |
* There is a fundamental race here that is solved by creating
|
272 |
* the first Tcl interpreter in a single threaded environment.
|
273 |
* Once the interpreter has been created, it is safe to create
|
274 |
* more threads that create interpreters in parallel.
|
275 |
*/
|
276 |
init = 1;
|
277 |
InitializeCriticalSection(&initLock);
|
278 |
InitializeCriticalSection(&masterLock);
|
279 |
}
|
280 |
EnterCriticalSection(&masterLock);
|
281 |
}
|
282 |
|
283 |
|
284 |
/*
|
285 |
*----------------------------------------------------------------------
|
286 |
*
|
287 |
* Tcl_GetAllocMutex
|
288 |
*
|
289 |
* This procedure returns a pointer to a statically initialized
|
290 |
* mutex for use by the memory allocator. The alloctor must
|
291 |
* use this lock, because all other locks are allocated...
|
292 |
*
|
293 |
* Results:
|
294 |
* A pointer to a mutex that is suitable for passing to
|
295 |
* Tcl_MutexLock and Tcl_MutexUnlock.
|
296 |
*
|
297 |
* Side effects:
|
298 |
* None.
|
299 |
*
|
300 |
*----------------------------------------------------------------------
|
301 |
*/
|
302 |
|
303 |
Tcl_Mutex *
|
304 |
Tcl_GetAllocMutex()
|
305 |
{
|
306 |
#ifdef TCL_THREADS
|
307 |
InitializeCriticalSection(&allocLock);
|
308 |
return &allocLockPtr;
|
309 |
#else
|
310 |
return NULL;
|
311 |
#endif
|
312 |
}
|
313 |
|
314 |
|
315 |
#ifdef TCL_THREADS
|
316 |
/*
|
317 |
*----------------------------------------------------------------------
|
318 |
*
|
319 |
* TclpMasterUnlock
|
320 |
*
|
321 |
* This procedure is used to release a lock that serializes creation
|
322 |
* and deletion of synchronization objects.
|
323 |
*
|
324 |
* Results:
|
325 |
* None.
|
326 |
*
|
327 |
* Side effects:
|
328 |
* Release the master mutex.
|
329 |
*
|
330 |
*----------------------------------------------------------------------
|
331 |
*/
|
332 |
|
333 |
void
|
334 |
TclpMasterUnlock()
|
335 |
{
|
336 |
LeaveCriticalSection(&masterLock);
|
337 |
}
|
338 |
|
339 |
|
340 |
/*
|
341 |
*----------------------------------------------------------------------
|
342 |
*
|
343 |
* Tcl_MutexLock --
|
344 |
*
|
345 |
* This procedure is invoked to lock a mutex. This is a self
|
346 |
* initializing mutex that is automatically finalized during
|
347 |
* Tcl_Finalize.
|
348 |
*
|
349 |
* Results:
|
350 |
* None.
|
351 |
*
|
352 |
* Side effects:
|
353 |
* May block the current thread. The mutex is aquired when
|
354 |
* this returns.
|
355 |
*
|
356 |
*----------------------------------------------------------------------
|
357 |
*/
|
358 |
|
359 |
void
|
360 |
Tcl_MutexLock(mutexPtr)
|
361 |
Tcl_Mutex *mutexPtr; /* The lock */
|
362 |
{
|
363 |
CRITICAL_SECTION *csPtr;
|
364 |
if (*mutexPtr == NULL) {
|
365 |
MASTER_LOCK;
|
366 |
|
367 |
/*
|
368 |
* Double inside master lock check to avoid a race.
|
369 |
*/
|
370 |
|
371 |
if (*mutexPtr == NULL) {
|
372 |
csPtr = (CRITICAL_SECTION *)ckalloc(sizeof(CRITICAL_SECTION));
|
373 |
InitializeCriticalSection(csPtr);
|
374 |
*mutexPtr = (Tcl_Mutex)csPtr;
|
375 |
TclRememberMutex(mutexPtr);
|
376 |
}
|
377 |
MASTER_UNLOCK;
|
378 |
}
|
379 |
csPtr = *((CRITICAL_SECTION **)mutexPtr);
|
380 |
EnterCriticalSection(csPtr);
|
381 |
}
|
382 |
|
383 |
|
384 |
/*
|
385 |
*----------------------------------------------------------------------
|
386 |
*
|
387 |
* Tcl_MutexUnlock --
|
388 |
*
|
389 |
* This procedure is invoked to unlock a mutex.
|
390 |
*
|
391 |
* Results:
|
392 |
* None.
|
393 |
*
|
394 |
* Side effects:
|
395 |
* The mutex is released when this returns.
|
396 |
*
|
397 |
*----------------------------------------------------------------------
|
398 |
*/
|
399 |
|
400 |
void
|
401 |
Tcl_MutexUnlock(mutexPtr)
|
402 |
Tcl_Mutex *mutexPtr; /* The lock */
|
403 |
{
|
404 |
CRITICAL_SECTION *csPtr = *((CRITICAL_SECTION **)mutexPtr);
|
405 |
LeaveCriticalSection(csPtr);
|
406 |
}
|
407 |
|
408 |
|
409 |
/*
|
410 |
*----------------------------------------------------------------------
|
411 |
*
|
412 |
* TclpFinalizeMutex --
|
413 |
*
|
414 |
* This procedure is invoked to clean up one mutex. This is only
|
415 |
* safe to call at the end of time.
|
416 |
*
|
417 |
* Results:
|
418 |
* None.
|
419 |
*
|
420 |
* Side effects:
|
421 |
* The mutex list is deallocated.
|
422 |
*
|
423 |
*----------------------------------------------------------------------
|
424 |
*/
|
425 |
|
426 |
void
|
427 |
TclpFinalizeMutex(mutexPtr)
|
428 |
Tcl_Mutex *mutexPtr;
|
429 |
{
|
430 |
CRITICAL_SECTION *csPtr = *(CRITICAL_SECTION **)mutexPtr;
|
431 |
if (csPtr != NULL) {
|
432 |
ckfree((char *)csPtr);
|
433 |
*mutexPtr = NULL;
|
434 |
}
|
435 |
}
|
436 |
|
437 |
|
438 |
/*
|
439 |
*----------------------------------------------------------------------
|
440 |
*
|
441 |
* TclpThreadDataKeyInit --
|
442 |
*
|
443 |
* This procedure initializes a thread specific data block key.
|
444 |
* Each thread has table of pointers to thread specific data.
|
445 |
* all threads agree on which table entry is used by each module.
|
446 |
* this is remembered in a "data key", that is just an index into
|
447 |
* this table. To allow self initialization, the interface
|
448 |
* passes a pointer to this key and the first thread to use
|
449 |
* the key fills in the pointer to the key. The key should be
|
450 |
* a process-wide static.
|
451 |
*
|
452 |
* Results:
|
453 |
* None.
|
454 |
*
|
455 |
* Side effects:
|
456 |
* Will allocate memory the first time this process calls for
|
457 |
* this key. In this case it modifies its argument
|
458 |
* to hold the pointer to information about the key.
|
459 |
*
|
460 |
*----------------------------------------------------------------------
|
461 |
*/
|
462 |
|
463 |
void
|
464 |
TclpThreadDataKeyInit(keyPtr)
|
465 |
Tcl_ThreadDataKey *keyPtr; /* Identifier for the data chunk,
|
466 |
* really (DWORD **) */
|
467 |
{
|
468 |
DWORD *indexPtr;
|
469 |
|
470 |
MASTER_LOCK;
|
471 |
if (*keyPtr == NULL) {
|
472 |
indexPtr = (DWORD *)ckalloc(sizeof(DWORD));
|
473 |
*indexPtr = TlsAlloc();
|
474 |
*keyPtr = (Tcl_ThreadDataKey)indexPtr;
|
475 |
TclRememberDataKey(keyPtr);
|
476 |
}
|
477 |
MASTER_UNLOCK;
|
478 |
}
|
479 |
|
480 |
|
481 |
/*
|
482 |
*----------------------------------------------------------------------
|
483 |
*
|
484 |
* TclpThreadDataKeyGet --
|
485 |
*
|
486 |
* This procedure returns a pointer to a block of thread local storage.
|
487 |
*
|
488 |
* Results:
|
489 |
* A thread-specific pointer to the data structure, or NULL
|
490 |
* if the memory has not been assigned to this key for this thread.
|
491 |
*
|
492 |
* Side effects:
|
493 |
* None.
|
494 |
*
|
495 |
*----------------------------------------------------------------------
|
496 |
*/
|
497 |
|
498 |
VOID *
|
499 |
TclpThreadDataKeyGet(keyPtr)
|
500 |
Tcl_ThreadDataKey *keyPtr; /* Identifier for the data chunk,
|
501 |
* really (DWORD **) */
|
502 |
{
|
503 |
DWORD *indexPtr = *(DWORD **)keyPtr;
|
504 |
if (indexPtr == NULL) {
|
505 |
return NULL;
|
506 |
} else {
|
507 |
return (VOID *) TlsGetValue(*indexPtr);
|
508 |
}
|
509 |
}
|
510 |
|
511 |
|
512 |
/*
|
513 |
*----------------------------------------------------------------------
|
514 |
*
|
515 |
* TclpThreadDataKeySet --
|
516 |
*
|
517 |
* This procedure sets the pointer to a block of thread local storage.
|
518 |
*
|
519 |
* Results:
|
520 |
* None.
|
521 |
*
|
522 |
* Side effects:
|
523 |
* Sets up the thread so future calls to TclpThreadDataKeyGet with
|
524 |
* this key will return the data pointer.
|
525 |
*
|
526 |
*----------------------------------------------------------------------
|
527 |
*/
|
528 |
|
529 |
void
|
530 |
TclpThreadDataKeySet(keyPtr, data)
|
531 |
Tcl_ThreadDataKey *keyPtr; /* Identifier for the data chunk,
|
532 |
* really (pthread_key_t **) */
|
533 |
VOID *data; /* Thread local storage */
|
534 |
{
|
535 |
DWORD *indexPtr = *(DWORD **)keyPtr;
|
536 |
TlsSetValue(*indexPtr, (void *)data);
|
537 |
}
|
538 |
|
539 |
|
540 |
/*
|
541 |
*----------------------------------------------------------------------
|
542 |
*
|
543 |
* TclpFinalizeThreadData --
|
544 |
*
|
545 |
* This procedure cleans up the thread-local storage. This is
|
546 |
* called once for each thread.
|
547 |
*
|
548 |
* Results:
|
549 |
* None.
|
550 |
*
|
551 |
* Side effects:
|
552 |
* Frees up the memory.
|
553 |
*
|
554 |
*----------------------------------------------------------------------
|
555 |
*/
|
556 |
|
557 |
void
|
558 |
TclpFinalizeThreadData(keyPtr)
|
559 |
Tcl_ThreadDataKey *keyPtr;
|
560 |
{
|
561 |
VOID *result;
|
562 |
DWORD *indexPtr;
|
563 |
|
564 |
if (*keyPtr != NULL) {
|
565 |
indexPtr = *(DWORD **)keyPtr;
|
566 |
result = (VOID *)TlsGetValue(*indexPtr);
|
567 |
if (result != NULL) {
|
568 |
ckfree((char *)result);
|
569 |
TlsSetValue(*indexPtr, (void *)NULL);
|
570 |
}
|
571 |
}
|
572 |
}
|
573 |
|
574 |
/*
|
575 |
*----------------------------------------------------------------------
|
576 |
*
|
577 |
* TclpFinalizeThreadDataKey --
|
578 |
*
|
579 |
* This procedure is invoked to clean up one key. This is a
|
580 |
* process-wide storage identifier. The thread finalization code
|
581 |
* cleans up the thread local storage itself.
|
582 |
*
|
583 |
* This assumes the master lock is held.
|
584 |
*
|
585 |
* Results:
|
586 |
* None.
|
587 |
*
|
588 |
* Side effects:
|
589 |
* The key is deallocated.
|
590 |
*
|
591 |
*----------------------------------------------------------------------
|
592 |
*/
|
593 |
|
594 |
void
|
595 |
TclpFinalizeThreadDataKey(keyPtr)
|
596 |
Tcl_ThreadDataKey *keyPtr;
|
597 |
{
|
598 |
DWORD *indexPtr;
|
599 |
if (*keyPtr != NULL) {
|
600 |
indexPtr = *(DWORD **)keyPtr;
|
601 |
TlsFree(*indexPtr);
|
602 |
ckfree((char *)indexPtr);
|
603 |
*keyPtr = NULL;
|
604 |
}
|
605 |
}
|
606 |
|
607 |
/*
|
608 |
*----------------------------------------------------------------------
|
609 |
*
|
610 |
* Tcl_ConditionWait --
|
611 |
*
|
612 |
* This procedure is invoked to wait on a condition variable.
|
613 |
* The mutex is automically released as part of the wait, and
|
614 |
* automatically grabbed when the condition is signaled.
|
615 |
*
|
616 |
* The mutex must be held when this procedure is called.
|
617 |
*
|
618 |
* Results:
|
619 |
* None.
|
620 |
*
|
621 |
* Side effects:
|
622 |
* May block the current thread. The mutex is aquired when
|
623 |
* this returns. Will allocate memory for a HANDLE
|
624 |
* and initialize this the first time this Tcl_Condition is used.
|
625 |
*
|
626 |
*----------------------------------------------------------------------
|
627 |
*/
|
628 |
|
629 |
void
|
630 |
Tcl_ConditionWait(condPtr, mutexPtr, timePtr)
|
631 |
Tcl_Condition *condPtr; /* Really (WinCondition **) */
|
632 |
Tcl_Mutex *mutexPtr; /* Really (CRITICAL_SECTION **) */
|
633 |
Tcl_Time *timePtr; /* Timeout on waiting period */
|
634 |
{
|
635 |
WinCondition *winCondPtr; /* Per-condition queue head */
|
636 |
CRITICAL_SECTION *csPtr; /* Caller's Mutex, after casting */
|
637 |
DWORD wtime; /* Windows time value */
|
638 |
int timeout; /* True if we got a timeout */
|
639 |
int doExit = 0; /* True if we need to do exit setup */
|
640 |
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
|
641 |
|
642 |
if (tsdPtr->flags & WIN_THREAD_DEAD) {
|
643 |
/*
|
644 |
* No more per-thread event on which to wait.
|
645 |
*/
|
646 |
|
647 |
return;
|
648 |
}
|
649 |
|
650 |
/*
|
651 |
* Self initialize the two parts of the contition.
|
652 |
* The per-condition and per-thread parts need to be
|
653 |
* handled independently.
|
654 |
*/
|
655 |
|
656 |
if (tsdPtr->flags == WIN_THREAD_UNINIT) {
|
657 |
MASTER_LOCK;
|
658 |
|
659 |
/*
|
660 |
* Create the per-thread event and queue pointers.
|
661 |
*/
|
662 |
|
663 |
if (tsdPtr->flags == WIN_THREAD_UNINIT) {
|
664 |
tsdPtr->condEvent = CreateEvent(NULL, TRUE /* manual reset */,
|
665 |
FALSE /* non signaled */, NULL);
|
666 |
tsdPtr->nextPtr = NULL;
|
667 |
tsdPtr->prevPtr = NULL;
|
668 |
tsdPtr->flags = WIN_THREAD_RUNNING;
|
669 |
doExit = 1;
|
670 |
}
|
671 |
MASTER_UNLOCK;
|
672 |
|
673 |
if (doExit) {
|
674 |
/*
|
675 |
* Create a per-thread exit handler to clean up the condEvent.
|
676 |
* We must be careful do do this outside the Master Lock
|
677 |
* because Tcl_CreateThreadExitHandler uses its own
|
678 |
* ThreadSpecificData, and initializing that may drop
|
679 |
* back into the Master Lock.
|
680 |
*/
|
681 |
|
682 |
Tcl_CreateThreadExitHandler(FinalizeConditionEvent,
|
683 |
(ClientData) tsdPtr);
|
684 |
}
|
685 |
}
|
686 |
|
687 |
if (*condPtr == NULL) {
|
688 |
MASTER_LOCK;
|
689 |
|
690 |
/*
|
691 |
* Initialize the per-condition queue pointers and Mutex.
|
692 |
*/
|
693 |
|
694 |
if (*condPtr == NULL) {
|
695 |
winCondPtr = (WinCondition *)ckalloc(sizeof(WinCondition));
|
696 |
InitializeCriticalSection(&winCondPtr->condLock);
|
697 |
winCondPtr->firstPtr = NULL;
|
698 |
winCondPtr->lastPtr = NULL;
|
699 |
*condPtr = (Tcl_Condition)winCondPtr;
|
700 |
TclRememberCondition(condPtr);
|
701 |
}
|
702 |
MASTER_UNLOCK;
|
703 |
}
|
704 |
csPtr = *((CRITICAL_SECTION **)mutexPtr);
|
705 |
winCondPtr = *((WinCondition **)condPtr);
|
706 |
if (timePtr == NULL) {
|
707 |
wtime = INFINITE;
|
708 |
} else {
|
709 |
wtime = timePtr->sec * 1000 + timePtr->usec / 1000;
|
710 |
}
|
711 |
|
712 |
/*
|
713 |
* Queue the thread on the condition, using
|
714 |
* the per-condition lock for serialization.
|
715 |
*/
|
716 |
|
717 |
tsdPtr->flags = WIN_THREAD_BLOCKED;
|
718 |
tsdPtr->nextPtr = NULL;
|
719 |
EnterCriticalSection(&winCondPtr->condLock);
|
720 |
tsdPtr->prevPtr = winCondPtr->lastPtr; /* A: */
|
721 |
winCondPtr->lastPtr = tsdPtr;
|
722 |
if (tsdPtr->prevPtr != NULL) {
|
723 |
tsdPtr->prevPtr->nextPtr = tsdPtr;
|
724 |
}
|
725 |
if (winCondPtr->firstPtr == NULL) {
|
726 |
winCondPtr->firstPtr = tsdPtr;
|
727 |
}
|
728 |
|
729 |
/*
|
730 |
* Unlock the caller's mutex and wait for the condition, or a timeout.
|
731 |
* There is a minor issue here in that we don't count down the
|
732 |
* timeout if we get notified, but another thread grabs the condition
|
733 |
* before we do. In that race condition we'll wait again for the
|
734 |
* full timeout. Timed waits are dubious anyway. Either you have
|
735 |
* the locking protocol wrong and are masking a deadlock,
|
736 |
* or you are using conditions to pause your thread.
|
737 |
*/
|
738 |
|
739 |
LeaveCriticalSection(csPtr);
|
740 |
timeout = 0;
|
741 |
while (!timeout && (tsdPtr->flags & WIN_THREAD_BLOCKED)) {
|
742 |
ResetEvent(tsdPtr->condEvent);
|
743 |
LeaveCriticalSection(&winCondPtr->condLock);
|
744 |
if (WaitForSingleObject(tsdPtr->condEvent, wtime) == WAIT_TIMEOUT) {
|
745 |
timeout = 1;
|
746 |
}
|
747 |
EnterCriticalSection(&winCondPtr->condLock);
|
748 |
}
|
749 |
|
750 |
/*
|
751 |
* Be careful on timeouts because the signal might arrive right around
|
752 |
* time time limit and someone else could have taken us off the queue.
|
753 |
*/
|
754 |
|
755 |
if (timeout) {
|
756 |
if (tsdPtr->flags & WIN_THREAD_RUNNING) {
|
757 |
timeout = 0;
|
758 |
} else {
|
759 |
/*
|
760 |
* When dequeuing, we can leave the tsdPtr->nextPtr
|
761 |
* and tsdPtr->prevPtr with dangling pointers because
|
762 |
* they are reinitialilzed w/out reading them when the
|
763 |
* thread is enqueued later.
|
764 |
*/
|
765 |
|
766 |
if (winCondPtr->firstPtr == tsdPtr) {
|
767 |
winCondPtr->firstPtr = tsdPtr->nextPtr;
|
768 |
} else {
|
769 |
tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
|
770 |
}
|
771 |
if (winCondPtr->lastPtr == tsdPtr) {
|
772 |
winCondPtr->lastPtr = tsdPtr->prevPtr;
|
773 |
} else {
|
774 |
tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
|
775 |
}
|
776 |
tsdPtr->flags = WIN_THREAD_RUNNING;
|
777 |
}
|
778 |
}
|
779 |
|
780 |
LeaveCriticalSection(&winCondPtr->condLock);
|
781 |
EnterCriticalSection(csPtr);
|
782 |
}
|
783 |
|
784 |
|
785 |
/*
|
786 |
*----------------------------------------------------------------------
|
787 |
*
|
788 |
* Tcl_ConditionNotify --
|
789 |
*
|
790 |
* This procedure is invoked to signal a condition variable.
|
791 |
*
|
792 |
* The mutex must be held during this call to avoid races,
|
793 |
* but this interface does not enforce that.
|
794 |
*
|
795 |
* Results:
|
796 |
* None.
|
797 |
*
|
798 |
* Side effects:
|
799 |
* May unblock another thread.
|
800 |
*
|
801 |
*----------------------------------------------------------------------
|
802 |
*/
|
803 |
|
804 |
void
|
805 |
Tcl_ConditionNotify(condPtr)
|
806 |
Tcl_Condition *condPtr;
|
807 |
{
|
808 |
WinCondition *winCondPtr;
|
809 |
ThreadSpecificData *tsdPtr;
|
810 |
if (condPtr != NULL) {
|
811 |
winCondPtr = *((WinCondition **)condPtr);
|
812 |
|
813 |
/*
|
814 |
* Loop through all the threads waiting on the condition
|
815 |
* and notify them (i.e., broadcast semantics). The queue
|
816 |
* manipulation is guarded by the per-condition coordinating mutex.
|
817 |
*/
|
818 |
|
819 |
EnterCriticalSection(&winCondPtr->condLock);
|
820 |
while (winCondPtr->firstPtr != NULL) {
|
821 |
tsdPtr = winCondPtr->firstPtr;
|
822 |
winCondPtr->firstPtr = tsdPtr->nextPtr;
|
823 |
if (winCondPtr->lastPtr == tsdPtr) {
|
824 |
winCondPtr->lastPtr = NULL;
|
825 |
}
|
826 |
tsdPtr->flags = WIN_THREAD_RUNNING;
|
827 |
tsdPtr->nextPtr = NULL;
|
828 |
tsdPtr->prevPtr = NULL; /* Not strictly necessary, see A: */
|
829 |
SetEvent(tsdPtr->condEvent);
|
830 |
}
|
831 |
LeaveCriticalSection(&winCondPtr->condLock);
|
832 |
} else {
|
833 |
/*
|
834 |
* Noone has used the condition variable, so there are no waiters.
|
835 |
*/
|
836 |
}
|
837 |
}
|
838 |
|
839 |
|
840 |
/*
|
841 |
*----------------------------------------------------------------------
|
842 |
*
|
843 |
* FinalizeConditionEvent --
|
844 |
*
|
845 |
* This procedure is invoked to clean up the per-thread
|
846 |
* event used to implement condition waiting.
|
847 |
* This is only safe to call at the end of time.
|
848 |
*
|
849 |
* Results:
|
850 |
* None.
|
851 |
*
|
852 |
* Side effects:
|
853 |
* The per-thread event is closed.
|
854 |
*
|
855 |
*----------------------------------------------------------------------
|
856 |
*/
|
857 |
|
858 |
static void
|
859 |
FinalizeConditionEvent(data)
|
860 |
ClientData data;
|
861 |
{
|
862 |
ThreadSpecificData *tsdPtr = (ThreadSpecificData *)data;
|
863 |
tsdPtr->flags = WIN_THREAD_DEAD;
|
864 |
CloseHandle(tsdPtr->condEvent);
|
865 |
}
|
866 |
|
867 |
/*
|
868 |
*----------------------------------------------------------------------
|
869 |
*
|
870 |
* TclpFinalizeCondition --
|
871 |
*
|
872 |
* This procedure is invoked to clean up a condition variable.
|
873 |
* This is only safe to call at the end of time.
|
874 |
*
|
875 |
* This assumes the Master Lock is held.
|
876 |
*
|
877 |
* Results:
|
878 |
* None.
|
879 |
*
|
880 |
* Side effects:
|
881 |
* The condition variable is deallocated.
|
882 |
*
|
883 |
*----------------------------------------------------------------------
|
884 |
*/
|
885 |
|
886 |
void
|
887 |
TclpFinalizeCondition(condPtr)
|
888 |
Tcl_Condition *condPtr;
|
889 |
{
|
890 |
WinCondition *winCondPtr = *(WinCondition **)condPtr;
|
891 |
|
892 |
/*
|
893 |
* Note - this is called long after the thread-local storage is
|
894 |
* reclaimed. The per-thread condition waiting event is
|
895 |
* reclaimed earlier in a per-thread exit handler, which is
|
896 |
* called before thread local storage is reclaimed.
|
897 |
*/
|
898 |
|
899 |
if (winCondPtr != NULL) {
|
900 |
ckfree((char *)winCondPtr);
|
901 |
*condPtr = NULL;
|
902 |
}
|
903 |
}
|
904 |
#endif /* TCL_THREADS */
|
905 |
|
906 |
/* End of tclwinthrd.c */
|