huschi.net

PTHREAD_MUTEX_TIMEDLOCK(3P)POSIX Programmer's ManuaPTHREAD_MUTEX_TIMEDLOCK(3P)

PROLOG
       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
       pthread_mutex_timedlock - lock a mutex (ADVANCED REALTIME)
SYNOPSIS
       #include <pthread.h>
       #include <time.h>
       int pthread_mutex_timedlock(pthread_mutex_t *restrict mutex,
              const struct timespec *restrict abs_timeout);

DESCRIPTION
       The pthread_mutex_timedlock() function shall lock the mutex object ref-
       erenced  by  mutex.  If the mutex is already locked, the calling thread
       shall  block  until   the   mutex   becomes   available   as   in   the
       pthread_mutex_lock()  function.  If  the mutex cannot be locked without
       waiting for another thread to unlock the mutex, this wait shall be ter-
       minated when the specified timeout expires.
       The  timeout shall expire when the absolute time specified by abs_time-
       out passes, as measured by the clock on which timeouts are based  (that
       is,  when the value of that clock equals or exceeds abs_timeout), or if
       the absolute time specified by abs_timeout has already been  passed  at
       the time of the call.
       If  the  Timers  option is supported, the timeout shall be based on the
       CLOCK_REALTIME clock; if the Timers option is not supported, the  time-
       out  shall be based on the system clock as returned by the time() func-
       tion.
       The resolution of the timeout shall be the resolution of the  clock  on
       which  it  is  based. The timespec data type is defined in the <time.h>
       header.
       Under no circumstance shall the function fail with  a  timeout  if  the
       mutex can be locked immediately. The validity of the abs_timeout param-
       eter need not be checked if the mutex can be locked immediately.
       As a consequence of the priority inheritance rules  (for  mutexes  ini-
       tialized with the PRIO_INHERIT protocol), if a timed mutex wait is ter-
       minated because its timeout expires, the priority of the owner  of  the
       mutex  shall  be  adjusted  as  necessary to reflect the fact that this
       thread is no longer among the threads waiting for the mutex.
RETURN VALUE
       If successful,  the  pthread_mutex_timedlock()  function  shall  return
       zero;  otherwise,  an  error  number  shall be returned to indicate the
       error.
ERRORS
       The pthread_mutex_timedlock() function shall fail if:
       EINVAL The mutex was created with the  protocol  attribute  having  the
              value  PTHREAD_PRIO_PROTECT and the calling thread's priority is
              higher than the mutex' current priority ceiling.
       EINVAL The process or thread would have blocked,  and  the  abs_timeout
              parameter  specified a nanoseconds field value less than zero or
              greater than or equal to 1000 million.
       ETIMEDOUT
              The mutex could not  be  locked  before  the  specified  timeout
              expired.

       The pthread_mutex_timedlock() function may fail if:
       EINVAL The  value  specified  by mutex does not refer to an initialized
              mutex object.
       EAGAIN The mutex could not be acquired because the  maximum  number  of
              recursive locks for mutex has been exceeded.
       EDEADLK
              The current thread already owns the mutex.

       This function shall not return an error code of [EINTR].
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       The pthread_mutex_timedlock() function is part of the Threads and Time-
       outs options and need not be provided on all implementations.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       pthread_mutex_destroy(), pthread_mutex_lock(), pthread_mutex_trylock(),
       time(),   the   Base   Definitions   volume   of  IEEE Std 1003.1-2001,
       <pthread.h>, <time.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 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 .

IEEE/The Open Group                  2003          PTHREAD_MUTEX_TIMEDLOCK(3P)