pthread_testcancel(3C)					   Standard C Library Functions 				    pthread_testcancel(3C)

NAME

       pthread_testcancel - create cancellation point in the calling thread

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       void pthread_testcancel(void);

DESCRIPTION

       The pthread_testcancel() function forces testing for cancellation. 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 cancellation 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 con-
       cepts.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       Intro(3), pthread_cleanup_pop(3C), pthread_cleanup_push(3C), pthread_exit(3C), pthread_join(3C),  pthread_setcancelstate(3C),  pthread_set-
       canceltype(3C), setjmp(3C), attributes(5), cancellation(5), condition(5), standards(5)

NOTES

       The pthread_testcancel() function has no effect if cancellation 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 argument 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  cancella-
       tion  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							    23 Mar 2005 					    pthread_testcancel(3C)