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pthread_mutexattr_gettype(3p) — Linux manual page

PTHREAD..._GETTYPE(3P)  POSIX Programmer's ManualPTHREAD..._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 *restrictattr,           int *restricttype);       int pthread_mutexattr_settype(pthread_mutexattr_t *attr, inttype);

DESCRIPTION        top

       Thepthread_mutexattr_gettype() andpthread_mutexattr_settype()       functions, respectively, shall get and set the mutextype       attribute. This attribute is set in thetype parameter to these       functions. The default value of thetype attribute is       PTHREAD_MUTEX_DEFAULT.       The type of mutex is contained in thetype 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. Seepthread_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 theattr       argument topthread_mutexattr_gettype() orpthread_mutexattr_settype() does not refer to an initialized mutex       attributes object.

RETURN VALUE        top

       Upon successful completion, thepthread_mutexattr_gettype()       function shall return zero and store the value of thetype       attribute ofattr into the object referenced by thetype       parameter. Otherwise, an error shall be returned to indicate the       error.       If successful, thepthread_mutexattr_settype() function shall       return zero; otherwise, an error number shall be returned to       indicate the error.

ERRORS        top

       Thepthread_mutexattr_settype() function shall fail if:EINVALThe valuetype 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 apthread_cond_timedwait() orpthread_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 theattr       argument topthread_mutexattr_gettype() orpthread_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 athttp://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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017PTHREAD..._GETTYPE(3P)

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

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