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pthread_cancel(3)
NAME
  pthread_cancel - Allows a thread to request a thread to terminate
  execution.

LIBRARY
  DECthreads POSIX 1003.1c Library (libpthread.so)

SYNOPSIS
  #include <pthread.h>

  int pthread_cancel(
		   pthread_t   thread);

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  IEEE Std 1003.1c-1995, POSIX System Application Program Interface

PARAMETERS
  thread    Thread that receives a cancelation request.

DESCRIPTION
  This routine sends a cancelation request to the specified target thread.  A
  cancelation request is a mechanism by which a calling thread requests the
  target thread to terminate as quickly as possible.  Issuing a cancelation
  request does not guarantee that the target thread will receive or handle
  the request.

  When the cancelation request is acted on, all active cleanup handler
  routines for the target thread are called.  When the last cleanup handler
  returns, the thread-specific data destructor routines are called for each
  thread-specific data key with a destructor and for which the target thread
  has a non-NULL value.	 Finally, the target thread is terminated.

  Note that cancelation of the target thread runs asynchronously with respect
  to the calling thread's returning from pthread_cancel(3).  The target
  thread's cancelability state and type determine when or if the cancelation
  takes place, as follows:

    ·  The target thread can delay cancelation during critical operations by
       setting its cancelability state to PTHREAD_CANCEL_DISABLE.

    ·  Because of communication delays, the calling thread can only rely on
       the fact that a cancelation request will eventually become pending in
       the target thread (provided that the target thread does not terminate
       beforehand).

    ·  The calling thread has no guarantee that a pending cancelation request
       will be delivered because delivery is controlled by the target thread.

  When a cancelation request is delivered to a thread, termination processing
  is similar to that for pthread_exit(3).  For more information about thread
  termination, see the discussion of thread termination in pthread_create(3).

  This routine is preferred in implementing an Ada abort statement and any
  other language- or software-defined construct for requesting thread
  cancelation.

  The results of this routine are unpredictable, if the value specified in
  thread refers to a thread that does not currently exist.

RETURN VALUES
  If an error condition occurs, this routine returns an integer value
  indicating the type of error.	 Possible return values are as follows:

  0	    Successful completion.

  [EINVAL]  The specified thread is invalid.

  [ESRCH]   The thread argument does not specify an existing thread.

ERRORS
  None

RELATED INFORMATION
  Functions: pthread_cleanup_pop(3), pthread_cleanup_push(3),
  pthread_create(3), pthread_exit(3), pthread_join(3),
  pthread_setcancelstate(3), pthread_setcanceltype(3), pthread_testcancel(3)

  Manuals: Guide to DECthreads and Programmer's Guide

Index for Section 3

Alphabetical listing for P

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