1PTHREAD_MUTEXATTR_GETTYPE(3PP)OSIX Programmer's ManuPaTlHREAD_MUTEXATTR_GETTYPE(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 pthread_mutexattr_gettype, pthread_mutexattr_settype — get and set the
13 mutex type attribute
14
16 #include <pthread.h>
17 int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict attr,
19 int *restrict type);
20 int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
21
23 The pthread_mutexattr_gettype() and pthread_mutexattr_settype() func‐
24 tions, respectively, shall get and set the mutex type attribute. This
25 attribute is set in the type parameter to these functions. The default
26 value of the type attribute is PTHREAD_MUTEX_DEFAULT.
27 The type of mutex is contained in the type attribute of the mutex
29 attributes. Valid mutex types include:
30 PTHREAD_MUTEX_NORMAL PTHREAD_MUTEX_ERRORCHECK
32 PTHREAD_MUTEX_RECURSIVE PTHREAD_MUTEX_DEFAULT
33 The mutex type affects the behavior of calls which lock and unlock the
35 mutex. See pthread_mutex_lock() for details. An implementation may map
36 PTHREAD_MUTEX_DEFAULT to one of the other mutex types.
37 The behavior is undefined if the value specified by the attr argument
39 to pthread_mutexattr_gettype() or pthread_mutexattr_settype() does not
40 refer to an initialized mutex attributes object.
41
43 Upon successful completion, the pthread_mutexattr_gettype() function
44 shall return zero and store the value of the type attribute of attr
45 into the object referenced by the type parameter. Otherwise, an error
46 shall be returned to indicate the error.
47 If successful, the pthread_mutexattr_settype() function shall return
49 zero; otherwise, an error number shall be returned to indicate the
50 error.
51
53 The pthread_mutexattr_settype() function shall fail if:
54 EINVAL The value type is invalid.
56 These functions shall not return an error code of [EINTR].
58 The following sections are informative.
60
62 None.
63
65 It is advised that an application should not use a PTHREAD_MUTEX_RECUR‐
66 SIVE mutex with condition variables because the implicit unlock per‐
67 formed for a pthread_cond_timedwait() or pthread_cond_wait() may not
68 actually release the mutex (if it had been locked multiple times). If
69 this happens, no other thread can satisfy the condition of the predi‐
70 cate.
71
73 If an implementation detects that the value specified by the attr argu‐
74 ment to pthread_mutexattr_gettype() or pthread_mutexattr_settype() does
75 not refer to an initialized mutex attributes object, it is recommended
76 that the function should fail and report an [EINVAL] error.
77
79 None.
80
82 pthread_cond_timedwait(), pthread_mutex_lock()
83 The Base Definitions volume of POSIX.1‐2017, <pthread.h>
85
87 Portions of this text are reprinted and reproduced in electronic form
88 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
89 table Operating System Interface (POSIX), The Open Group Base Specifi‐
90 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
91 Electrical and Electronics Engineers, Inc and The Open Group. In the
92 event of any discrepancy between this version and the original IEEE and
93 The Open Group Standard, the original IEEE and The Open Group Standard
94 is the referee document. The original Standard can be obtained online
95 at http://www.opengroup.org/unix/online.html .
96 Any typographical or formatting errors that appear in this page are
98 most likely to have been introduced during the conversion of the source
99 files to man page format. To report such errors, see https://www.ker‐
100 nel.org/doc/man-pages/reporting_bugs.html .
101IEEE/The Open Group 2017 PTHREAD_MUTEXATTR_GETTYPE(3P)