pthread_mutexattr_gettype(3p) — Linux manual page

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

PTHREAD_MUTEXATTR_GETTYPE(3P) Programmer's ManualD_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.1‐2017, pthread.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  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.opengroup.org/unix/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               2017     PTHREAD_MUTEXATTR_GETTYPE(3P)

Pages that refer to this page: pthread.h(0p)pthread_mutexattr_settype(3p)