source: mainline/kernel/generic/include/synch/mutex.h

Last change on this file was 9f2f5ee, checked in by Jiří Zárevúcky <zarevucky.jiri@…>, 3 months ago

Rewrite kernel mutex implementation a little

Removes MUTEX_ACTIVE, the use of which has been removed in favor of
irq_spinlock_t, and fixes some issues with the old implementation.

  • A race in mtx→owner access is unavoidable, so make it explicitly atomic.
  • The THREAD==NULL case happens when there are no other threads yet, so we factor it out as a special case. Also ensures recursive mutex works before threads are initialized, just as normal mutex does.
  • More and better asserts.
  • Property mode set to 100644
File size: 2.3 KB
Line 
1/*
2 * Copyright (c) 2001-2004 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup kernel_sync
30 * @{
31 */
32/** @file
33 */
34
35#ifndef KERN_MUTEX_H_
36#define KERN_MUTEX_H_
37
38#include <stdbool.h>
39#include <stdint.h>
40#include <synch/semaphore.h>
41#include <abi/synch.h>
42
43typedef enum {
44 MUTEX_PASSIVE,
45 MUTEX_RECURSIVE,
46} mutex_type_t;
47
48struct thread;
49
50typedef struct {
51 mutex_type_t type;
52 int nesting;
53 semaphore_t sem;
54 _Atomic(struct thread *) owner;
55} mutex_t;
56
57#define MUTEX_INITIALIZER(name, mtype) (mutex_t) { \
58 .type = (mtype), \
59 .nesting = 0, \
60 .sem = SEMAPHORE_INITIALIZER((name).sem, 1), \
61 .owner = NULL, \
62}
63
64#define MUTEX_INITIALIZE(name, mtype) \
65 mutex_t name = MUTEX_INITIALIZER(name, mtype)
66
67extern void mutex_initialize(mutex_t *, mutex_type_t);
68extern bool mutex_locked(mutex_t *);
69extern errno_t mutex_trylock(mutex_t *);
70extern void mutex_lock(mutex_t *);
71extern errno_t mutex_lock_timeout(mutex_t *, uint32_t);
72extern void mutex_unlock(mutex_t *);
73
74#endif
75
76/** @}
77 */
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