pthread_rwlock_timedrdlock(3p) — Linux manual page

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

PTHREAD_RWLOCK_TIMEDRDLOCK(3P)Programmer'sPManual_RWLOCK_TIMEDRDLOCK(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_timedrdlock — lock a read-write lock for reading

SYNOPSIS         top

       #include <pthread.h>
       #include <time.h>

       int pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict rwlock,
           const struct timespec *restrict abstime);

DESCRIPTION         top

       The pthread_rwlock_timedrdlock() function shall apply a read lock
       to the read-write lock referenced by rwlock as in the
       pthread_rwlock_rdlock() function. However, if the lock cannot be
       acquired without waiting for other threads to unlock the lock,
       this wait shall be terminated when the specified timeout expires.
       The timeout shall expire when the absolute time specified by
       abstime passes, as measured by the clock on which timeouts are
       based (that is, when the value of that clock equals or exceeds
       abstime), or if the absolute time specified by abstime has
       already been passed at the time of the call.

       The timeout shall be based on the CLOCK_REALTIME clock.  The
       resolution of the timeout shall be the resolution of the
       CLOCK_REALTIME clock. The timespec data type is defined in the
       <time.h> header. Under no circumstances shall the function fail
       with a timeout if the lock can be acquired immediately. The
       validity of the abstime parameter need not be checked if the lock
       can be immediately acquired.

       If a signal that causes a signal handler to be executed is
       delivered to a thread blocked on a read-write lock via a call to
       pthread_rwlock_timedrdlock(), upon return from the signal handler
       the thread shall resume waiting for the lock as if it was not
       interrupted.

       The calling thread may deadlock if at the time the call is made
       it holds a write lock on rwlock.  The results are undefined if
       this function is called with an uninitialized read-write lock.

RETURN VALUE         top

       The pthread_rwlock_timedrdlock() function shall return zero if
       the lock for reading on the read-write lock object referenced by
       rwlock is acquired. Otherwise, an error number shall be returned
       to indicate the error.

ERRORS         top

       The pthread_rwlock_timedrdlock() function shall fail if:

       ETIMEDOUT
              The lock could not be acquired before the specified
              timeout expired.

       The pthread_rwlock_timedrdlock() function may fail if:

       EAGAIN The read lock could not be acquired because the maximum
              number of read locks for lock would be exceeded.

       EDEADLK
              A deadlock condition was detected or the calling thread
              already holds a write lock on rwlock.

       EINVAL The abstime nanosecond value is less than zero or greater
              than or equal to 1000 million.

       This function shall not return an error code of [EINTR].

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       Applications using this function may be subject to priority
       inversion, as discussed in the Base Definitions volume of
       POSIX.1‐2017, Section 3.291, Priority Inversion.

RATIONALE         top

       If an implementation detects that the value specified by the
       rwlock argument to pthread_rwlock_timedrdlock() does not refer to
       an initialized read-write lock object, it is recommended that the
       function should fail and report an [EINVAL] error.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       pthread_rwlock_destroy(3p), pthread_rwlock_rdlock(3p),
       pthread_rwlock_timedwrlock(3p), pthread_rwlock_trywrlock(3p),
       pthread_rwlock_unlock(3p)

       The Base Definitions volume of POSIX.1‐2017, Section 3.291,
       Priority Inversion, Section 4.12, Memory Synchronization,
       pthread.h(0p), time.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_RWLOCK_TIMEDRDLOCK(3P)

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