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pthread_cancel - Allows a thread to request a thread to terminate execution
pthread_t thread );
DECthreads POSIX 1003.1c Library (libpthread.so)
Interfaces documented on this reference page conform to industry standards
IEEE Std 1003.1c-1995, POSIX System Application Program Interface
Thread that receives a cancellation request.
This routine sends a cancellation request to the specified target thread. A
cancellation request is a mechanism by which a calling thread requests the
target thread to terminate as quickly as possible. Issuing a cancellation
request does not guarantee that the target thread will receive or handle
When the cancellation 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 cancellation 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
cancellation takes place, as follows:
· The target thread can delay cancellation 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 cancellation request will eventually become pending in
the target thread (provided that the target thread does not terminate
· The calling thread has no guarantee that a pending cancellation
request will be delivered because delivery is controlled by the target
When a cancellation 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
This routine is preferred in implementing an Ada abort statement and any
other language- or software-defined construct for requesting thread
The results of this routine are unpredictable, if the value specified in
thread refers to a thread that does not currently exist.
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.
The specified thread is invalid.
The thread argument does not specify an existing thread.
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
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