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1/* Locking in multithreaded situations.
2 Copyright (C) 2005-2013 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, see <http://www.gnu.org/licenses/>. */
16
17/* Written by Bruno Haible <bruno@clisp.org>, 2005.
18 Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h,
19 gthr-win32.h. */
20
21/* This file contains locking primitives for use with a given thread library.
22 It does not contain primitives for creating threads or for other
23 synchronization primitives.
24
25 Normal (non-recursive) locks:
26 Type: gl_lock_t
27 Declaration: gl_lock_define(extern, name)
28 Initializer: gl_lock_define_initialized(, name)
29 Initialization: gl_lock_init (name);
30 Taking the lock: gl_lock_lock (name);
31 Releasing the lock: gl_lock_unlock (name);
32 De-initialization: gl_lock_destroy (name);
33 Equivalent functions with control of error handling:
34 Initialization: err = glthread_lock_init (&name);
35 Taking the lock: err = glthread_lock_lock (&name);
36 Releasing the lock: err = glthread_lock_unlock (&name);
37 De-initialization: err = glthread_lock_destroy (&name);
38
39 Read-Write (non-recursive) locks:
40 Type: gl_rwlock_t
41 Declaration: gl_rwlock_define(extern, name)
42 Initializer: gl_rwlock_define_initialized(, name)
43 Initialization: gl_rwlock_init (name);
44 Taking the lock: gl_rwlock_rdlock (name);
45 gl_rwlock_wrlock (name);
46 Releasing the lock: gl_rwlock_unlock (name);
47 De-initialization: gl_rwlock_destroy (name);
48 Equivalent functions with control of error handling:
49 Initialization: err = glthread_rwlock_init (&name);
50 Taking the lock: err = glthread_rwlock_rdlock (&name);
51 err = glthread_rwlock_wrlock (&name);
52 Releasing the lock: err = glthread_rwlock_unlock (&name);
53 De-initialization: err = glthread_rwlock_destroy (&name);
54
55 Recursive locks:
56 Type: gl_recursive_lock_t
57 Declaration: gl_recursive_lock_define(extern, name)
58 Initializer: gl_recursive_lock_define_initialized(, name)
59 Initialization: gl_recursive_lock_init (name);
60 Taking the lock: gl_recursive_lock_lock (name);
61 Releasing the lock: gl_recursive_lock_unlock (name);
62 De-initialization: gl_recursive_lock_destroy (name);
63 Equivalent functions with control of error handling:
64 Initialization: err = glthread_recursive_lock_init (&name);
65 Taking the lock: err = glthread_recursive_lock_lock (&name);
66 Releasing the lock: err = glthread_recursive_lock_unlock (&name);
67 De-initialization: err = glthread_recursive_lock_destroy (&name);
68
69 Once-only execution:
70 Type: gl_once_t
71 Initializer: gl_once_define(extern, name)
72 Execution: gl_once (name, initfunction);
73 Equivalent functions with control of error handling:
74 Execution: err = glthread_once (&name, initfunction);
75*/
76
77
78#ifndef _LOCK_H
79#define _LOCK_H
80
81#include <errno.h>
82#include <stdlib.h>
83
84/* ========================================================================= */
85
86#if USE_POSIX_THREADS
87
88/* Use the POSIX threads library. */
89
90# include <pthread.h>
91
92# ifdef __cplusplus
93extern "C" {
94# endif
95
96# if PTHREAD_IN_USE_DETECTION_HARD
97
98/* The pthread_in_use() detection needs to be done at runtime. */
99# define pthread_in_use() \
100 glthread_in_use ()
101extern int glthread_in_use (void);
102
103# endif
104
105# if USE_POSIX_THREADS_WEAK
106
107/* Use weak references to the POSIX threads library. */
108
109/* Weak references avoid dragging in external libraries if the other parts
110 of the program don't use them. Here we use them, because we don't want
111 every program that uses libintl to depend on libpthread. This assumes
112 that libpthread would not be loaded after libintl; i.e. if libintl is
113 loaded first, by an executable that does not depend on libpthread, and
114 then a module is dynamically loaded that depends on libpthread, libintl
115 will not be multithread-safe. */
116
117/* The way to test at runtime whether libpthread is present is to test
118 whether a function pointer's value, such as &pthread_mutex_init, is
119 non-NULL. However, some versions of GCC have a bug through which, in
120 PIC mode, &foo != NULL always evaluates to true if there is a direct
121 call to foo(...) in the same function. To avoid this, we test the
122 address of a function in libpthread that we don't use. */
123
124# pragma weak pthread_mutex_init
125# pragma weak pthread_mutex_lock
126# pragma weak pthread_mutex_unlock
127# pragma weak pthread_mutex_destroy
128# pragma weak pthread_rwlock_init
129# pragma weak pthread_rwlock_rdlock
130# pragma weak pthread_rwlock_wrlock
131# pragma weak pthread_rwlock_unlock
132# pragma weak pthread_rwlock_destroy
133# pragma weak pthread_once
134# pragma weak pthread_cond_init
135# pragma weak pthread_cond_wait
136# pragma weak pthread_cond_signal
137# pragma weak pthread_cond_broadcast
138# pragma weak pthread_cond_destroy
139# pragma weak pthread_mutexattr_init
140# pragma weak pthread_mutexattr_settype
141# pragma weak pthread_mutexattr_destroy
142# ifndef pthread_self
143# pragma weak pthread_self
144# endif
145
146# if !PTHREAD_IN_USE_DETECTION_HARD
147# pragma weak pthread_cancel
148# define pthread_in_use() (pthread_cancel != NULL)
149# endif
150
151# else
152
153# if !PTHREAD_IN_USE_DETECTION_HARD
154# define pthread_in_use() 1
155# endif
156
157# endif
158
159/* -------------------------- gl_lock_t datatype -------------------------- */
160
161typedef pthread_mutex_t gl_lock_t;
162# define gl_lock_define(STORAGECLASS, NAME) \
163 STORAGECLASS pthread_mutex_t NAME;
164# define gl_lock_define_initialized(STORAGECLASS, NAME) \
165 STORAGECLASS pthread_mutex_t NAME = gl_lock_initializer;
166# define gl_lock_initializer \
167 PTHREAD_MUTEX_INITIALIZER
168# define glthread_lock_init(LOCK) \
169 (pthread_in_use () ? pthread_mutex_init (LOCK, NULL) : 0)
170# define glthread_lock_lock(LOCK) \
171 (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
172# define glthread_lock_unlock(LOCK) \
173 (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
174# define glthread_lock_destroy(LOCK) \
175 (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
176
177/* ------------------------- gl_rwlock_t datatype ------------------------- */
178
179# if HAVE_PTHREAD_RWLOCK
180
181# ifdef PTHREAD_RWLOCK_INITIALIZER
182
183typedef pthread_rwlock_t gl_rwlock_t;
184# define gl_rwlock_define(STORAGECLASS, NAME) \
185 STORAGECLASS pthread_rwlock_t NAME;
186# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
187 STORAGECLASS pthread_rwlock_t NAME = gl_rwlock_initializer;
188# define gl_rwlock_initializer \
189 PTHREAD_RWLOCK_INITIALIZER
190# define glthread_rwlock_init(LOCK) \
191 (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0)
192# define glthread_rwlock_rdlock(LOCK) \
193 (pthread_in_use () ? pthread_rwlock_rdlock (LOCK) : 0)
194# define glthread_rwlock_wrlock(LOCK) \
195 (pthread_in_use () ? pthread_rwlock_wrlock (LOCK) : 0)
196# define glthread_rwlock_unlock(LOCK) \
197 (pthread_in_use () ? pthread_rwlock_unlock (LOCK) : 0)
198# define glthread_rwlock_destroy(LOCK) \
199 (pthread_in_use () ? pthread_rwlock_destroy (LOCK) : 0)
200
201# else
202
203typedef struct
204 {
205 int initialized;
206 pthread_mutex_t guard; /* protects the initialization */
207 pthread_rwlock_t rwlock; /* read-write lock */
208 }
209 gl_rwlock_t;
210# define gl_rwlock_define(STORAGECLASS, NAME) \
211 STORAGECLASS gl_rwlock_t NAME;
212# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
213 STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
214# define gl_rwlock_initializer \
215 { 0, PTHREAD_MUTEX_INITIALIZER }
216# define glthread_rwlock_init(LOCK) \
217 (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
218# define glthread_rwlock_rdlock(LOCK) \
219 (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
220# define glthread_rwlock_wrlock(LOCK) \
221 (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
222# define glthread_rwlock_unlock(LOCK) \
223 (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
224# define glthread_rwlock_destroy(LOCK) \
225 (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
226extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
227extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
228extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
229extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
230extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
231
232# endif
233
234# else
235
236typedef struct
237 {
238 pthread_mutex_t lock; /* protects the remaining fields */
239 pthread_cond_t waiting_readers; /* waiting readers */
240 pthread_cond_t waiting_writers; /* waiting writers */
241 unsigned int waiting_writers_count; /* number of waiting writers */
242 int runcount; /* number of readers running, or -1 when a writer runs */
243 }
244 gl_rwlock_t;
245# define gl_rwlock_define(STORAGECLASS, NAME) \
246 STORAGECLASS gl_rwlock_t NAME;
247# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
248 STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
249# define gl_rwlock_initializer \
250 { PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, 0, 0 }
251# define glthread_rwlock_init(LOCK) \
252 (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
253# define glthread_rwlock_rdlock(LOCK) \
254 (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
255# define glthread_rwlock_wrlock(LOCK) \
256 (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
257# define glthread_rwlock_unlock(LOCK) \
258 (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
259# define glthread_rwlock_destroy(LOCK) \
260 (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
261extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
262extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
263extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
264extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
265extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
266
267# endif
268
269/* --------------------- gl_recursive_lock_t datatype --------------------- */
270
271# if HAVE_PTHREAD_MUTEX_RECURSIVE
272
273# if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
274
275typedef pthread_mutex_t gl_recursive_lock_t;
276# define gl_recursive_lock_define(STORAGECLASS, NAME) \
277 STORAGECLASS pthread_mutex_t NAME;
278# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
279 STORAGECLASS pthread_mutex_t NAME = gl_recursive_lock_initializer;
280# ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER
281# define gl_recursive_lock_initializer \
282 PTHREAD_RECURSIVE_MUTEX_INITIALIZER
283# else
284# define gl_recursive_lock_initializer \
285 PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
286# endif
287# define glthread_recursive_lock_init(LOCK) \
288 (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
289# define glthread_recursive_lock_lock(LOCK) \
290 (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
291# define glthread_recursive_lock_unlock(LOCK) \
292 (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
293# define glthread_recursive_lock_destroy(LOCK) \
294 (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
295extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
296
297# else
298
299typedef struct
300 {
301 pthread_mutex_t recmutex; /* recursive mutex */
302 pthread_mutex_t guard; /* protects the initialization */
303 int initialized;
304 }
305 gl_recursive_lock_t;
306# define gl_recursive_lock_define(STORAGECLASS, NAME) \
307 STORAGECLASS gl_recursive_lock_t NAME;
308# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
309 STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
310# define gl_recursive_lock_initializer \
311 { PTHREAD_MUTEX_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, 0 }
312# define glthread_recursive_lock_init(LOCK) \
313 (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
314# define glthread_recursive_lock_lock(LOCK) \
315 (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
316# define glthread_recursive_lock_unlock(LOCK) \
317 (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
318# define glthread_recursive_lock_destroy(LOCK) \
319 (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
320extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
321extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
322extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
323extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
324
325# endif
326
327# else
328
329/* Old versions of POSIX threads on Solaris did not have recursive locks.
330 We have to implement them ourselves. */
331
332typedef struct
333 {
334 pthread_mutex_t mutex;
335 pthread_t owner;
336 unsigned long depth;
337 }
338 gl_recursive_lock_t;
339# define gl_recursive_lock_define(STORAGECLASS, NAME) \
340 STORAGECLASS gl_recursive_lock_t NAME;
341# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
342 STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
343# define gl_recursive_lock_initializer \
344 { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0, 0 }
345# define glthread_recursive_lock_init(LOCK) \
346 (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
347# define glthread_recursive_lock_lock(LOCK) \
348 (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
349# define glthread_recursive_lock_unlock(LOCK) \
350 (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
351# define glthread_recursive_lock_destroy(LOCK) \
352 (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
353extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
354extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
355extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
356extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
357
358# endif
359
360/* -------------------------- gl_once_t datatype -------------------------- */
361
362typedef pthread_once_t gl_once_t;
363# define gl_once_define(STORAGECLASS, NAME) \
364 STORAGECLASS pthread_once_t NAME = PTHREAD_ONCE_INIT;
365# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
366 (pthread_in_use () \
367 ? pthread_once (ONCE_CONTROL, INITFUNCTION) \
368 : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
369extern int glthread_once_singlethreaded (pthread_once_t *once_control);
370
371# ifdef __cplusplus
372}
373# endif
374
375#endif
376
377/* ========================================================================= */
378
379#if USE_PTH_THREADS
380
381/* Use the GNU Pth threads library. */
382
383# include <pth.h>
384
385# ifdef __cplusplus
386extern "C" {
387# endif
388
389# if USE_PTH_THREADS_WEAK
390
391/* Use weak references to the GNU Pth threads library. */
392
393# pragma weak pth_mutex_init
394# pragma weak pth_mutex_acquire
395# pragma weak pth_mutex_release
396# pragma weak pth_rwlock_init
397# pragma weak pth_rwlock_acquire
398# pragma weak pth_rwlock_release
399# pragma weak pth_once
400
401# pragma weak pth_cancel
402# define pth_in_use() (pth_cancel != NULL)
403
404# else
405
406# define pth_in_use() 1
407
408# endif
409
410/* -------------------------- gl_lock_t datatype -------------------------- */
411
412typedef pth_mutex_t gl_lock_t;
413# define gl_lock_define(STORAGECLASS, NAME) \
414 STORAGECLASS pth_mutex_t NAME;
415# define gl_lock_define_initialized(STORAGECLASS, NAME) \
416 STORAGECLASS pth_mutex_t NAME = gl_lock_initializer;
417# define gl_lock_initializer \
418 PTH_MUTEX_INIT
419# define glthread_lock_init(LOCK) \
420 (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0)
421# define glthread_lock_lock(LOCK) \
422 (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0)
423# define glthread_lock_unlock(LOCK) \
424 (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0)
425# define glthread_lock_destroy(LOCK) \
426 ((void)(LOCK), 0)
427
428/* ------------------------- gl_rwlock_t datatype ------------------------- */
429
430typedef pth_rwlock_t gl_rwlock_t;
431# define gl_rwlock_define(STORAGECLASS, NAME) \
432 STORAGECLASS pth_rwlock_t NAME;
433# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
434 STORAGECLASS pth_rwlock_t NAME = gl_rwlock_initializer;
435# define gl_rwlock_initializer \
436 PTH_RWLOCK_INIT
437# define glthread_rwlock_init(LOCK) \
438 (pth_in_use () && !pth_rwlock_init (LOCK) ? errno : 0)
439# define glthread_rwlock_rdlock(LOCK) \
440 (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RD, 0, NULL) ? errno : 0)
441# define glthread_rwlock_wrlock(LOCK) \
442 (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RW, 0, NULL) ? errno : 0)
443# define glthread_rwlock_unlock(LOCK) \
444 (pth_in_use () && !pth_rwlock_release (LOCK) ? errno : 0)
445# define glthread_rwlock_destroy(LOCK) \
446 ((void)(LOCK), 0)
447
448/* --------------------- gl_recursive_lock_t datatype --------------------- */
449
450/* In Pth, mutexes are recursive by default. */
451typedef pth_mutex_t gl_recursive_lock_t;
452# define gl_recursive_lock_define(STORAGECLASS, NAME) \
453 STORAGECLASS pth_mutex_t NAME;
454# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
455 STORAGECLASS pth_mutex_t NAME = gl_recursive_lock_initializer;
456# define gl_recursive_lock_initializer \
457 PTH_MUTEX_INIT
458# define glthread_recursive_lock_init(LOCK) \
459 (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0)
460# define glthread_recursive_lock_lock(LOCK) \
461 (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0)
462# define glthread_recursive_lock_unlock(LOCK) \
463 (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0)
464# define glthread_recursive_lock_destroy(LOCK) \
465 ((void)(LOCK), 0)
466
467/* -------------------------- gl_once_t datatype -------------------------- */
468
469typedef pth_once_t gl_once_t;
470# define gl_once_define(STORAGECLASS, NAME) \
471 STORAGECLASS pth_once_t NAME = PTH_ONCE_INIT;
472# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
473 (pth_in_use () \
474 ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION) \
475 : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
476extern int glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void));
477extern int glthread_once_singlethreaded (pth_once_t *once_control);
478
479# ifdef __cplusplus
480}
481# endif
482
483#endif
484
485/* ========================================================================= */
486
487#if USE_SOLARIS_THREADS
488
489/* Use the old Solaris threads library. */
490
491# include <thread.h>
492# include <synch.h>
493
494# ifdef __cplusplus
495extern "C" {
496# endif
497
498# if USE_SOLARIS_THREADS_WEAK
499
500/* Use weak references to the old Solaris threads library. */
501
502# pragma weak mutex_init
503# pragma weak mutex_lock
504# pragma weak mutex_unlock
505# pragma weak mutex_destroy
506# pragma weak rwlock_init
507# pragma weak rw_rdlock
508# pragma weak rw_wrlock
509# pragma weak rw_unlock
510# pragma weak rwlock_destroy
511# pragma weak thr_self
512
513# pragma weak thr_suspend
514# define thread_in_use() (thr_suspend != NULL)
515
516# else
517
518# define thread_in_use() 1
519
520# endif
521
522/* -------------------------- gl_lock_t datatype -------------------------- */
523
524typedef mutex_t gl_lock_t;
525# define gl_lock_define(STORAGECLASS, NAME) \
526 STORAGECLASS mutex_t NAME;
527# define gl_lock_define_initialized(STORAGECLASS, NAME) \
528 STORAGECLASS mutex_t NAME = gl_lock_initializer;
529# define gl_lock_initializer \
530 DEFAULTMUTEX
531# define glthread_lock_init(LOCK) \
532 (thread_in_use () ? mutex_init (LOCK, USYNC_THREAD, NULL) : 0)
533# define glthread_lock_lock(LOCK) \
534 (thread_in_use () ? mutex_lock (LOCK) : 0)
535# define glthread_lock_unlock(LOCK) \
536 (thread_in_use () ? mutex_unlock (LOCK) : 0)
537# define glthread_lock_destroy(LOCK) \
538 (thread_in_use () ? mutex_destroy (LOCK) : 0)
539
540/* ------------------------- gl_rwlock_t datatype ------------------------- */
541
542typedef rwlock_t gl_rwlock_t;
543# define gl_rwlock_define(STORAGECLASS, NAME) \
544 STORAGECLASS rwlock_t NAME;
545# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
546 STORAGECLASS rwlock_t NAME = gl_rwlock_initializer;
547# define gl_rwlock_initializer \
548 DEFAULTRWLOCK
549# define glthread_rwlock_init(LOCK) \
550 (thread_in_use () ? rwlock_init (LOCK, USYNC_THREAD, NULL) : 0)
551# define glthread_rwlock_rdlock(LOCK) \
552 (thread_in_use () ? rw_rdlock (LOCK) : 0)
553# define glthread_rwlock_wrlock(LOCK) \
554 (thread_in_use () ? rw_wrlock (LOCK) : 0)
555# define glthread_rwlock_unlock(LOCK) \
556 (thread_in_use () ? rw_unlock (LOCK) : 0)
557# define glthread_rwlock_destroy(LOCK) \
558 (thread_in_use () ? rwlock_destroy (LOCK) : 0)
559
560/* --------------------- gl_recursive_lock_t datatype --------------------- */
561
562/* Old Solaris threads did not have recursive locks.
563 We have to implement them ourselves. */
564
565typedef struct
566 {
567 mutex_t mutex;
568 thread_t owner;
569 unsigned long depth;
570 }
571 gl_recursive_lock_t;
572# define gl_recursive_lock_define(STORAGECLASS, NAME) \
573 STORAGECLASS gl_recursive_lock_t NAME;
574# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
575 STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
576# define gl_recursive_lock_initializer \
577 { DEFAULTMUTEX, (thread_t) 0, 0 }
578# define glthread_recursive_lock_init(LOCK) \
579 (thread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
580# define glthread_recursive_lock_lock(LOCK) \
581 (thread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
582# define glthread_recursive_lock_unlock(LOCK) \
583 (thread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
584# define glthread_recursive_lock_destroy(LOCK) \
585 (thread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
586extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
587extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
588extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
589extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
590
591/* -------------------------- gl_once_t datatype -------------------------- */
592
593typedef struct
594 {
595 volatile int inited;
596 mutex_t mutex;
597 }
598 gl_once_t;
599# define gl_once_define(STORAGECLASS, NAME) \
600 STORAGECLASS gl_once_t NAME = { 0, DEFAULTMUTEX };
601# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
602 (thread_in_use () \
603 ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION) \
604 : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
605extern int glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void));
606extern int glthread_once_singlethreaded (gl_once_t *once_control);
607
608# ifdef __cplusplus
609}
610# endif
611
612#endif
613
614/* ========================================================================= */
615
616#if USE_WINDOWS_THREADS
617
618# define WIN32_LEAN_AND_MEAN /* avoid including junk */
619# include <windows.h>
620
621# ifdef __cplusplus
622extern "C" {
623# endif
624
625/* We can use CRITICAL_SECTION directly, rather than the native Windows Event,
626 Mutex, Semaphore types, because
627 - we need only to synchronize inside a single process (address space),
628 not inter-process locking,
629 - we don't need to support trylock operations. (TryEnterCriticalSection
630 does not work on Windows 95/98/ME. Packages that need trylock usually
631 define their own mutex type.) */
632
633/* There is no way to statically initialize a CRITICAL_SECTION. It needs
634 to be done lazily, once only. For this we need spinlocks. */
635
636typedef struct { volatile int done; volatile long started; } gl_spinlock_t;
637
638/* -------------------------- gl_lock_t datatype -------------------------- */
639
640typedef struct
641 {
642 gl_spinlock_t guard; /* protects the initialization */
643 CRITICAL_SECTION lock;
644 }
645 gl_lock_t;
646# define gl_lock_define(STORAGECLASS, NAME) \
647 STORAGECLASS gl_lock_t NAME;
648# define gl_lock_define_initialized(STORAGECLASS, NAME) \
649 STORAGECLASS gl_lock_t NAME = gl_lock_initializer;
650# define gl_lock_initializer \
651 { { 0, -1 } }
652# define glthread_lock_init(LOCK) \
653 (glthread_lock_init_func (LOCK), 0)
654# define glthread_lock_lock(LOCK) \
655 glthread_lock_lock_func (LOCK)
656# define glthread_lock_unlock(LOCK) \
657 glthread_lock_unlock_func (LOCK)
658# define glthread_lock_destroy(LOCK) \
659 glthread_lock_destroy_func (LOCK)
660extern void glthread_lock_init_func (gl_lock_t *lock);
661extern int glthread_lock_lock_func (gl_lock_t *lock);
662extern int glthread_lock_unlock_func (gl_lock_t *lock);
663extern int glthread_lock_destroy_func (gl_lock_t *lock);
664
665/* ------------------------- gl_rwlock_t datatype ------------------------- */
666
667/* It is impossible to implement read-write locks using plain locks, without
668 introducing an extra thread dedicated to managing read-write locks.
669 Therefore here we need to use the low-level Event type. */
670
671typedef struct
672 {
673 HANDLE *array; /* array of waiting threads, each represented by an event */
674 unsigned int count; /* number of waiting threads */
675 unsigned int alloc; /* length of allocated array */
676 unsigned int offset; /* index of first waiting thread in array */
677 }
678 gl_carray_waitqueue_t;
679typedef struct
680 {
681 gl_spinlock_t guard; /* protects the initialization */
682 CRITICAL_SECTION lock; /* protects the remaining fields */
683 gl_carray_waitqueue_t waiting_readers; /* waiting readers */
684 gl_carray_waitqueue_t waiting_writers; /* waiting writers */
685 int runcount; /* number of readers running, or -1 when a writer runs */
686 }
687 gl_rwlock_t;
688# define gl_rwlock_define(STORAGECLASS, NAME) \
689 STORAGECLASS gl_rwlock_t NAME;
690# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
691 STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
692# define gl_rwlock_initializer \
693 { { 0, -1 } }
694# define glthread_rwlock_init(LOCK) \
695 (glthread_rwlock_init_func (LOCK), 0)
696# define glthread_rwlock_rdlock(LOCK) \
697 glthread_rwlock_rdlock_func (LOCK)
698# define glthread_rwlock_wrlock(LOCK) \
699 glthread_rwlock_wrlock_func (LOCK)
700# define glthread_rwlock_unlock(LOCK) \
701 glthread_rwlock_unlock_func (LOCK)
702# define glthread_rwlock_destroy(LOCK) \
703 glthread_rwlock_destroy_func (LOCK)
704extern void glthread_rwlock_init_func (gl_rwlock_t *lock);
705extern int glthread_rwlock_rdlock_func (gl_rwlock_t *lock);
706extern int glthread_rwlock_wrlock_func (gl_rwlock_t *lock);
707extern int glthread_rwlock_unlock_func (gl_rwlock_t *lock);
708extern int glthread_rwlock_destroy_func (gl_rwlock_t *lock);
709
710/* --------------------- gl_recursive_lock_t datatype --------------------- */
711
712/* The native Windows documentation says that CRITICAL_SECTION already
713 implements a recursive lock. But we need not rely on it: It's easy to
714 implement a recursive lock without this assumption. */
715
716typedef struct
717 {
718 gl_spinlock_t guard; /* protects the initialization */
719 DWORD owner;
720 unsigned long depth;
721 CRITICAL_SECTION lock;
722 }
723 gl_recursive_lock_t;
724# define gl_recursive_lock_define(STORAGECLASS, NAME) \
725 STORAGECLASS gl_recursive_lock_t NAME;
726# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
727 STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
728# define gl_recursive_lock_initializer \
729 { { 0, -1 }, 0, 0 }
730# define glthread_recursive_lock_init(LOCK) \
731 (glthread_recursive_lock_init_func (LOCK), 0)
732# define glthread_recursive_lock_lock(LOCK) \
733 glthread_recursive_lock_lock_func (LOCK)
734# define glthread_recursive_lock_unlock(LOCK) \
735 glthread_recursive_lock_unlock_func (LOCK)
736# define glthread_recursive_lock_destroy(LOCK) \
737 glthread_recursive_lock_destroy_func (LOCK)
738extern void glthread_recursive_lock_init_func (gl_recursive_lock_t *lock);
739extern int glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock);
740extern int glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock);
741extern int glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock);
742
743/* -------------------------- gl_once_t datatype -------------------------- */
744
745typedef struct
746 {
747 volatile int inited;
748 volatile long started;
749 CRITICAL_SECTION lock;
750 }
751 gl_once_t;
752# define gl_once_define(STORAGECLASS, NAME) \
753 STORAGECLASS gl_once_t NAME = { -1, -1 };
754# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
755 (glthread_once_func (ONCE_CONTROL, INITFUNCTION), 0)
756extern void glthread_once_func (gl_once_t *once_control, void (*initfunction) (void));
757
758# ifdef __cplusplus
759}
760# endif
761
762#endif
763
764/* ========================================================================= */
765
766#if !(USE_POSIX_THREADS || USE_PTH_THREADS || USE_SOLARIS_THREADS || USE_WINDOWS_THREADS)
767
768/* Provide dummy implementation if threads are not supported. */
769
770/* -------------------------- gl_lock_t datatype -------------------------- */
771
772typedef int gl_lock_t;
773# define gl_lock_define(STORAGECLASS, NAME)
774# define gl_lock_define_initialized(STORAGECLASS, NAME)
775# define glthread_lock_init(NAME) 0
776# define glthread_lock_lock(NAME) 0
777# define glthread_lock_unlock(NAME) 0
778# define glthread_lock_destroy(NAME) 0
779
780/* ------------------------- gl_rwlock_t datatype ------------------------- */
781
782typedef int gl_rwlock_t;
783# define gl_rwlock_define(STORAGECLASS, NAME)
784# define gl_rwlock_define_initialized(STORAGECLASS, NAME)
785# define glthread_rwlock_init(NAME) 0
786# define glthread_rwlock_rdlock(NAME) 0
787# define glthread_rwlock_wrlock(NAME) 0
788# define glthread_rwlock_unlock(NAME) 0
789# define glthread_rwlock_destroy(NAME) 0
790
791/* --------------------- gl_recursive_lock_t datatype --------------------- */
792
793typedef int gl_recursive_lock_t;
794# define gl_recursive_lock_define(STORAGECLASS, NAME)
795# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME)
796# define glthread_recursive_lock_init(NAME) 0
797# define glthread_recursive_lock_lock(NAME) 0
798# define glthread_recursive_lock_unlock(NAME) 0
799# define glthread_recursive_lock_destroy(NAME) 0
800
801/* -------------------------- gl_once_t datatype -------------------------- */
802
803typedef int gl_once_t;
804# define gl_once_define(STORAGECLASS, NAME) \
805 STORAGECLASS gl_once_t NAME = 0;
806# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
807 (*(ONCE_CONTROL) == 0 ? (*(ONCE_CONTROL) = ~ 0, INITFUNCTION (), 0) : 0)
808
809#endif
810
811/* ========================================================================= */
812
813/* Macros with built-in error handling. */
814
815/* -------------------------- gl_lock_t datatype -------------------------- */
816
817#define gl_lock_init(NAME) \
818 do \
819 { \
820 if (glthread_lock_init (&NAME)) \
821 abort (); \
822 } \
823 while (0)
824#define gl_lock_lock(NAME) \
825 do \
826 { \
827 if (glthread_lock_lock (&NAME)) \
828 abort (); \
829 } \
830 while (0)
831#define gl_lock_unlock(NAME) \
832 do \
833 { \
834 if (glthread_lock_unlock (&NAME)) \
835 abort (); \
836 } \
837 while (0)
838#define gl_lock_destroy(NAME) \
839 do \
840 { \
841 if (glthread_lock_destroy (&NAME)) \
842 abort (); \
843 } \
844 while (0)
845
846/* ------------------------- gl_rwlock_t datatype ------------------------- */
847
848#define gl_rwlock_init(NAME) \
849 do \
850 { \
851 if (glthread_rwlock_init (&NAME)) \
852 abort (); \
853 } \
854 while (0)
855#define gl_rwlock_rdlock(NAME) \
856 do \
857 { \
858 if (glthread_rwlock_rdlock (&NAME)) \
859 abort (); \
860 } \
861 while (0)
862#define gl_rwlock_wrlock(NAME) \
863 do \
864 { \
865 if (glthread_rwlock_wrlock (&NAME)) \
866 abort (); \
867 } \
868 while (0)
869#define gl_rwlock_unlock(NAME) \
870 do \
871 { \
872 if (glthread_rwlock_unlock (&NAME)) \
873 abort (); \
874 } \
875 while (0)
876#define gl_rwlock_destroy(NAME) \
877 do \
878 { \
879 if (glthread_rwlock_destroy (&NAME)) \
880 abort (); \
881 } \
882 while (0)
883
884/* --------------------- gl_recursive_lock_t datatype --------------------- */
885
886#define gl_recursive_lock_init(NAME) \
887 do \
888 { \
889 if (glthread_recursive_lock_init (&NAME)) \
890 abort (); \
891 } \
892 while (0)
893#define gl_recursive_lock_lock(NAME) \
894 do \
895 { \
896 if (glthread_recursive_lock_lock (&NAME)) \
897 abort (); \
898 } \
899 while (0)
900#define gl_recursive_lock_unlock(NAME) \
901 do \
902 { \
903 if (glthread_recursive_lock_unlock (&NAME)) \
904 abort (); \
905 } \
906 while (0)
907#define gl_recursive_lock_destroy(NAME) \
908 do \
909 { \
910 if (glthread_recursive_lock_destroy (&NAME)) \
911 abort (); \
912 } \
913 while (0)
914
915/* -------------------------- gl_once_t datatype -------------------------- */
916
917#define gl_once(NAME, INITFUNCTION) \
918 do \
919 { \
920 if (glthread_once (&NAME, INITFUNCTION)) \
921 abort (); \
922 } \
923 while (0)
924
925/* ========================================================================= */
926
927#endif /* _LOCK_H */