pthread_cleanup_push

- push a thread cancellation cleanup handler

Synopsis

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

void pthread_cleanup_push(void (*handler) (void *), void *arg);

Description

The pthread_cleanup_push() function pushes the specified cancellation cleanup handler routine, handler, onto the cancellation cleanup stack of the calling thread.

When a thread exits or is canceled and its cancellation cleanup stack is not empty, the cleanup handlers are invoked with the argument arg in last in, first out (LIFO) order from the cancellation cleanup stack.

An exiting or cancelled thread runs with all signals blocked. All thread termination functions, including cancellation cleanup handlers, are called with all signals blocked.

The pthread_cleanup_push() and pthread_cleanup_pop(3C) functions can be implemented as macros. The application must ensure that they appear as statements, and in pairs within the same lexical scope (that is, the pthread_cleanup_push() macro can be thought to expand to a token list whose first token is '{' with pthread_cleanup_pop() expanding to a token list whose last token is the corresponding '}').

The effect of the use of return, break, continue, and goto to prematurely leave a code block described by a pair of pthread_cleanup_push() and pthread_cleanup_pop() function calls is undefined.

Using longjmp() or siglongjmp() to jump into or out of a push/pop pair can cause either the matching push or the matching pop statement not getting executed.

Return Values

The pthread_cleanup_push() function returns no value.

Errors

No errors are defined.

The pthread_cleanup_push() function will not return an error code of EINTR.

Attributes

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

See Also

longjmp(3C), pthread_cancel(3C), pthread_cleanup_pop(3C), pthread_exit(3C), pthread_join(3C), pthread_setcancelstate(3C), pthread_setcanceltype(3C), pthread_testcancel(3C), attributes(5), cancellation(5), condition(5), standards(5)

Notes

See cancellation(5) for a discussion of cancellation concepts.