pthread_cancel(3p) — Linux manual page


PTHREAD_CANCEL(3P)      POSIX Programmer's Manual     PTHREAD_CANCEL(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_cancel — cancel execution of a thread

SYNOPSIS         top

       #include <pthread.h>

       int pthread_cancel(pthread_t thread);

DESCRIPTION         top

       The pthread_cancel() function shall request that thread be
       canceled. The target thread's cancelability state and type
       determines when the cancellation takes effect. When the
       cancellation is acted on, the cancellation cleanup handlers for
       thread shall be called. When the last cancellation cleanup
       handler returns, the thread-specific data destructor functions
       shall be called for thread.  When the last destructor function
       returns, thread shall be terminated.

       The cancellation processing in the target thread shall run
       asynchronously with respect to the calling thread returning from

RETURN VALUE         top

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

ERRORS         top

       The pthread_cancel() function shall not return an error code of

       The following sections are informative.

EXAMPLES         top




RATIONALE         top

       Two alternative functions were considered for sending the
       cancellation notification to a thread. One would be to define a
       new SIGCANCEL signal that had the cancellation semantics when
       delivered; the other was to define the new pthread_cancel()
       function, which would trigger the cancellation semantics.

       The advantage of a new signal was that so much of the delivery
       criteria were identical to that used when trying to deliver a
       signal that making cancellation notification a signal was seen as
       consistent. Indeed, many implementations implement cancellation
       using a special signal. On the other hand, there would be no
       signal functions that could be used with this signal except
       pthread_kill(), and the behavior of the delivered cancellation
       signal would be unlike any previously existing defined signal.

       The benefits of a special function include the recognition that
       this signal would be defined because of the similar delivery
       criteria and that this is the only common behavior between a
       cancellation request and a signal. In addition, the cancellation
       delivery mechanism does not have to be implemented as a signal.
       There are also strong, if not stronger, parallels with language
       exception mechanisms than with signals that are potentially
       obscured if the delivery mechanism is visibly closer to signals.

       In the end, it was considered that as there were so many
       exceptions to the use of the new signal with existing signals
       functions it would be misleading. A special function has resolved
       this problem.  This function was carefully defined so that an
       implementation wishing to provide the cancellation functions on
       top of signals could do so.  The special function also means that
       implementations are not obliged to implement cancellation with

       If an implementation detects use of a thread ID after the end of
       its lifetime, it is recommended that the function should fail and
       report an [ESRCH] error.



SEE ALSO         top

       pthread_exit(3p), pthread_cond_timedwait(3p), pthread_join(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 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               2017                PTHREAD_CANCEL(3P)

Pages that refer to this page: pthread.h(0p)pthread_cleanup_pop(3p)pthread_setcancelstate(3p)