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pthread_rwlock_unlock(3p) — Linux manual page

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

PTHREAD...K_UNLOCK(3P)  POSIX Programmer's ManualPTHREAD...K_UNLOCK(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_rwlock_unlock — unlock a read-write lock object

SYNOPSIS top

       #include <pthread.h>       int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);

DESCRIPTION top

       Thepthread_rwlock_unlock() function shall release a lock held on       the read-write lock object referenced byrwlock.  Results are       undefined if the read-write lockrwlock is not held by the calling       thread.       If this function is called to release a read lock from the read-       write lock object and there are other read locks currently held on       this read-write lock object, the read-write lock object remains in       the read locked state. If this function releases the last read       lock for this read-write lock object, the read-write lock object       shall be put in the unlocked state with no owners.       If this function is called to release a write lock for this read-       write lock object, the read-write lock object shall be put in the       unlocked state.       If there are threads blocked on the lock when it becomes       available, the scheduling policy shall determine which thread(s)       shall acquire the lock.  If the Thread Execution Scheduling option       is supported, when threads executing with the scheduling policies       SCHED_FIFO, SCHED_RR, or SCHED_SPORADIC are waiting on the lock,       they shall acquire the lock in priority order when the lock       becomes available. For equal priority threads, write locks shall       take precedence over read locks.  If the Thread Execution       Scheduling option is not supported, it is implementation-defined       whether write locks take precedence over read locks.       Results are undefined if this function is called with an       uninitialized read-write lock.

RETURN VALUE top

       If successful, thepthread_rwlock_unlock() function shall return       zero; otherwise, an error number shall be returned to indicate the       error.

ERRORS top

       Thepthread_rwlock_unlock() function shall not return an error       code of[EINTR].The following sections are informative.

EXAMPLES top

       None.

APPLICATION USAGE top

       None.

RATIONALE top

       If an implementation detects that the value specified by therwlock argument topthread_rwlock_unlock() does not refer to an       initialized read-write lock object, it is recommended that the       function should fail and report an[EINVAL]error.       If an implementation detects that the value specified by therwlock argument topthread_rwlock_unlock() refers to a read-write       lock object for which the current thread does not hold a lock, it       is recommended that the function should fail and report an[EPERM]       error.

FUTURE DIRECTIONS top

       None.

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...K_UNLOCK(3P)

Pages that refer to this page:pthread.h(0p), pthread_rwlock_destroy(3p), pthread_rwlock_rdlock(3p), pthread_rwlock_timedrdlock(3p), pthread_rwlock_timedwrlock(3p), pthread_rwlock_trywrlock(3p)

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