pthread_setcancelstate(3)pthread_setcancelstate(3)NAMEpthread_setcancelstate - Sets the calling thread's cancelability state
int *oldstate );
DECthreads POSIX 1003.1c Library (libpthread.so)
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
IEEE Std 1003.1c-1995, POSIX System Application Program Interface
State of general cancelability to set for the calling thread. The fol‐
lowing are valid cancel state values: PTHREAD_CANCEL_ENABLE
PTHREAD_CANCEL_DISABLE Previous cancelability state for the calling
This routine sets the current thread's cancelability state and returns
the calling thread's previous cancelability state in oldstate.
When cancelability state is set to PTHREAD_CANCEL_DISABLE, a cancella‐
tion request cannot be delivered to the thread, even if a cancelable
routine is called or asynchronous cancelability type is enabled.
When a thread is created, the default cancelability state is
Possible Problems When Disabling Cancelability
The most important use of thread cancellation is to ensure that indefi‐
nite wait operations are terminated. For example, a thread that waits
on some network connection, which can possibly take days to respond (or
might never respond), should be made cancelable.
When a thread's cancelability is disabled, no routine in that thread is
cancelable. As a result, the user is unable to cancel the operation
performed by that thread. When disabling cancelability, be sure that no
long waits can occur or that it is necessary for other reasons to defer
cancellation requests around that particular region of code.
On successful completion, this routine returns the calling thread's
previous cancelability state in the location specified by the oldstate
If an error condition occurs, this routine returns an integer value
indicating the type of error. Possible return values are as follows:
Successful completion. The specified state is not PTHREAD_CAN‐
CEL_ENABLE or PTHREAD_CANCEL_DISABLE.
Functions: pthread_cancel(3), pthread_setcanceltype(3), pthread_test‐
Manuals: Guide to DECthreads and Programmer's Guide