NAME

pthread_atfork — register handlers to be called before and after fork()

SYNOPSIS

#include <pthread.h>

int
pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void));

DESCRIPTION

The pthread_atfork() function declares fork handlers to be called before and after fork(2), in the context of the thread that called fork(2).

The handlers registered with pthread_atfork() are called at the moments in time described below:

prepare

Before fork(2) processing commences in the parent process. If more than one prepare handler is registered they will be called in the opposite order they were registered.

parent

After fork(2) completes in the parent process. If more than one parent handler is registered they will be called in the same order they were registered.

child

After fork(2) processing completes in the child process. If more than one child handler is registered they will be called in the same order they were registered.

If no handling is desired at one or more of these three points, a null pointer may be passed as the corresponding fork handler.

Important: only async-signal-safe functions are allowed on the child side of fork(). See sigaction(2) for details.

RETURN VALUES

If successful, the pthread_atfork() function will return zero. Otherwise an error number will be returned to indicate the error.

ERRORS

The pthread_atfork() function will fail if:

[ENOMEM]

The system lacked the necessary resources to add another handler to the list.

SEE ALSO

fork(2), pthread(3)

STANDARDS

The pthread_atfork() conforms to ISO/IEC 9945-1:1996 (“POSIX.1”).