pthread_rwlock_timedrdlock(3p) — Linux manual page



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

       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:

              The lock could not be acquired before the specified timeout

       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.

              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



       Applications using this function may be subject to priority
       inversion, as discussed in the Base Definitions volume of
       POSIX.1‐2008, Section 3.287, 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.



SEE ALSO         top

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

       The  Base Definitions volume of POSIX.1‐2008, Section 3.287, Priority
       Inversion,  Section  4.11,  Memory  Synchronization,   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 .

       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 .

IEEE/The Open Group                 2013      PTHREAD_RWLOCK_TIMEDRDLOCK(3P)

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