PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

PTHREAD_MUTEXATTR_GETTYPE(3P)IX Programmer's ManualEAD_MUTEXATTR_GETTYPE(3P)

PROLOG         top

       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.

NAME         top

       pthread_mutexattr_gettype, pthread_mutexattr_settype — get and set
       the mutex type attribute

SYNOPSIS         top

       #include <pthread.h>

       int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict attr,
           int *restrict type);
       int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);

DESCRIPTION         top

       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:

              PTHREAD_MUTEX_NORMAL PTHREAD_MUTEX_ERRORCHECK
              PTHREAD_MUTEX_RECURSIVE PTHREAD_MUTEX_DEFAULT

       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.

RETURN VALUE         top

       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
       error.

ERRORS         top

       The pthread_mutexattr_settype() function shall fail if:

       EINVAL The value type is invalid.

       These functions shall not return an error code of [EINTR].

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       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.

RATIONALE         top

       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.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       pthread_cond_timedwait(3p), pthread_mutex_lock(3p)

       The Base Definitions volume of POSIX.1‐2008, pthread.h(0p)

COPYRIGHT         top

       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
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013       PTHREAD_MUTEXATTR_GETTYPE(3P)