Manual Pages for UNIX Operating System command usage for man pthread_testcancel

Standard C Library Functions               pthread_testcancel(3C)



NAME
     pthread_testcancel - create cancellation point in  the  cal-
     ling thread

SYNOPSIS
     cc -mt [ flag... ] file... -lpthread [ library... ]
     #include 

     void pthread_testcancel(void);


DESCRIPTION
     The pthread_testcancel() function forces testing for cancel-
     lation.  This  is useful  when you need to execute code that
     runs for  long  periods  without  encountering  cancellation
     points; such as a library routine that executes long-running
     computations without cancellation points. This type of  code
     can  block  cancellation  for  unacceptable  long periods of
     time.   One strategy for avoiding blocking cancellation  for
     long  periods, is to insert calls to pthread_testcancel() in
     the long-running computation code and to setup  a  cancella-
     tion handler in the library code, if required.

RETURN VALUES
     The pthread_testcancel() function returns void.

ERRORS
     The pthread_testcancel() function does not return errors.

EXAMPLES
     See   cancellation(5)    for    an    example    of    using
     pthread_testcancel() to force testing for cancellation and a
     discussion of cancellation concepts.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:


















SunOS 5.11          Last change: 23 Mar 2005                    1






Standard C Library Functions               pthread_testcancel(3C)



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     Intro(3), pthread_cleanup_pop(3C), pthread_cleanup_push(3C),
     pthread_exit(3C),                          pthread_join(3C),
     pthread_setcancelstate(3C),       pthread_setcanceltype(3C),
     setjmp(3C),  attributes(5),  cancellation(5),  condition(5),
     standards(5)

NOTES
     The pthread_testcancel() function has no effect if cancella-
     tion is disabled.


     Use pthread_testcancel() with pthread_setcanceltype() called
     with  its  canceltype  set  to  PTHREAD_CANCEL_DEFERRED. The
     pthread_testcancel()  function  operation  is  undefined  if
     pthread_setcanceltype() was called with its canceltype argu-
     ment set to PTHREAD_CANCEL_ASYNCHRONOUS.


     It is possible to  kill  a  thread  when  it  is  holding  a
     resource,  such  as lock or allocated memory. If that thread
     has not setup a cancellation cleanup handler to release  the
     held  resource,  the  application  is  "cancel-unsafe".  See
     attributes(5) for a discussion of  Cancel-Safety,  Deferred-
     Cancel-Safety, and Asynchronous-Cancel-Safety.



















SunOS 5.11          Last change: 23 Mar 2005                    2