This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
The pthread_mutexattr_gettype() and pthread_mutexattr_settype()
functions, respectively, shall get and set the mutex type attribute.
This attribute is set in the type parameter to these functions. The
default value of the type attribute is PTHREAD_MUTEX_DEFAULT.
The type of mutex is contained in the type attribute of the mutex
attributes. Valid mutex types include:
The mutex type affects the behavior of calls which lock and unlock
the mutex. See pthread_mutex_lock(3p) for details. An implementation
may map PTHREAD_MUTEX_DEFAULT to one of the other mutex types.
The behavior is undefined if the value specified by the attr argument
to pthread_mutexattr_gettype() or pthread_mutexattr_settype() does
not refer to an initialized mutex attributes object.
Upon successful completion, the pthread_mutexattr_gettype() function
shall return zero and store the value of the type attribute of attr
into the object referenced by the type parameter. Otherwise, an error
shall be returned to indicate the error.
If successful, the pthread_mutexattr_settype() function shall return
zero; otherwise, an error number shall be returned to indicate the
It is advised that an application should not use a
PTHREAD_MUTEX_RECURSIVE mutex with condition variables because the
implicit unlock performed for a pthread_cond_timedwait() or
pthread_cond_wait() may not actually release the mutex (if it had
been locked multiple times). If this happens, no other thread can
satisfy the condition of the predicate.
If an implementation detects that the value specified by the attr
argument to pthread_mutexattr_gettype() or
pthread_mutexattr_settype() does not refer to an initialized mutex
attributes object, it is recommended that the function should fail
and report an [EINVAL] error.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) In the event of any discrepancy between this version and
the original IEEE and The Open Group Standard, the original IEEE and
The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
IEEE/The Open Group 2013 PTHREAD_MUTEXATTR_GETTYPE(3P)