pthread_cleanup_pop.3t (2010 09)

p
pthread_cleanup_pop(3T) pthread_cleanup_pop(3T)
(Pthread Library)
NAME
pthread_cleanup_pop(), pthread_cleanup_push() - remove or register a cancellation cleanup handler
SYNOPSIS
#include <pthread.h>
void pthread_cleanup_push(
void (*routine)(void *),
void *arg
);
void pthread_cleanup_pop(
int execute
);
PARAMETERS
routine Routine registered as a cancellation cleanup handler.
arg Parameter to be passed to the cancellation cleanup handler
routine().
execute Indicates if the popped cancellation cleanup handler is to be executed.
DESCRIPTION
pthread_cleanup_push()
installs the cancellation cleanup handler routine onto the calling thread’s
cancellation cleanup stack. This handler will be popped from the calling thread’s cancellation cleanup
stack and called with the arg parameter when any of the following occur:
(a) the thread calls
pthread_exit()
or returns from its start routine.
(b) the thread acts upon a cancellation request.
(c) the thread calls
pthread_cleanup_pop()
with a non-zero execute argument.
When a thread terminates, it will execute each of the cancellation cleanup handlers on its cancellation
cleanup stack. These handlers will be popped and executed in the reverse order that they were installed
(Last-In, First-Out).
pthread_cleanup_pop()
removes the cancellation cleanup handler at the top of the calling thread’s
cancellation stack. If execute is non-zero, the cancellation cleanup handler is called after it is removed
from the cancellation stack. If execute is zero, the cancellation cleanup handler is simply removed and
will not be called.
pthread_cleanup_push()
and pthread_cleanup_pop() must appear as statements and in
pairs within the same lexical scope. These functions may be macros which contain the opening ’{’ in the
push function and the closing ’}’ in the pop function.
Calling
longjmp() or siglongjmp() is undefined if there have been any calls to
pthread_cleanup_push()
or pthread_cleanup_pop() made without the matching call since
the jump buffer was filled.
Calling
longjmp() or siglongjmp() from inside a cancellation cleanup handler results in undefined
behavior unless the corresponding setjmp() or sigsetjmp() was also done inside the cancellation
cleanup handler.
RETURN VALUE
The
pthread_cleanup_push() and pthread_cleanup_pop()
functions must be used as state-
ments. They do not have return values or errors.
ERRORS
None.
WARNINGS
The functions
pthread_cleanup_push() and pthread_cleanup_pop() must be called in the
same lexical scope or the result is undefined behavior.
AUTHOR
pthread_cleanup_push() and pthread_cleanup_pop() were derived from the IEEE POSIX
P1003.1c standard.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1