1 /* Timed read-write locks (native Windows implementation).
2    Copyright (C) 2019-2021 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 <https://www.gnu.org/licenses/>.  */
16 
17 /* Written by Bruno Haible <bruno@clisp.org>, 2019.  */
18 
19 #ifndef _WINDOWS_TIMEDRWLOCK_H
20 #define _WINDOWS_TIMEDRWLOCK_H
21 
22 #define WIN32_LEAN_AND_MEAN  /* avoid including junk */
23 #include <windows.h>
24 
25 #include <time.h>
26 
27 #include "windows-initguard.h"
28 
29 #ifndef _glwthread_linked_waitqueue_link_defined
30 #define _glwthread_linked_waitqueue_link_defined
31 struct glwthread_waitqueue_link
32 {
33   struct glwthread_waitqueue_link *wql_next;
34   struct glwthread_waitqueue_link *wql_prev;
35 };
36 #endif /* _glwthread_linked_waitqueue_link_defined */
37 typedef struct
38         {
39           struct glwthread_waitqueue_link wq_list; /* circular list of waiting threads */
40           unsigned int count; /* number of waiting threads */
41         }
42         glwthread_clinked_waitqueue_t;
43 
44 typedef struct
45         {
46           glwthread_initguard_t guard; /* protects the initialization */
47           CRITICAL_SECTION lock; /* protects the remaining fields */
48           glwthread_clinked_waitqueue_t waiting_readers; /* waiting readers */
49           glwthread_clinked_waitqueue_t waiting_writers; /* waiting writers */
50           int runcount; /* number of readers running, or -1 when a writer runs */
51         }
52         glwthread_timedrwlock_t;
53 
54 #define GLWTHREAD_TIMEDRWLOCK_INIT { GLWTHREAD_INITGUARD_INIT }
55 
56 #ifdef __cplusplus
57 extern "C" {
58 #endif
59 
60 extern void glwthread_timedrwlock_init (glwthread_timedrwlock_t *lock);
61 extern int glwthread_timedrwlock_rdlock (glwthread_timedrwlock_t *lock);
62 extern int glwthread_timedrwlock_wrlock (glwthread_timedrwlock_t *lock);
63 extern int glwthread_timedrwlock_tryrdlock (glwthread_timedrwlock_t *lock);
64 extern int glwthread_timedrwlock_trywrlock (glwthread_timedrwlock_t *lock);
65 extern int glwthread_timedrwlock_timedrdlock (glwthread_timedrwlock_t *lock,
66                                               const struct timespec *abstime);
67 extern int glwthread_timedrwlock_timedwrlock (glwthread_timedrwlock_t *lock,
68                                               const struct timespec *abstime);
69 extern int glwthread_timedrwlock_unlock (glwthread_timedrwlock_t *lock);
70 extern int glwthread_timedrwlock_destroy (glwthread_timedrwlock_t *lock);
71 
72 #ifdef __cplusplus
73 }
74 #endif
75 
76 #endif /* _WINDOWS_TIMEDRWLOCK_H */
77