[apple/libc.git] / pthreads / pthread_atfork.3

.\" Copyright (c) 2004 Apple Computer, Inc.
.\"
.Dd August 12, 2004
.Dt PTHREAD_ATFORK 3
.Os
.Sh NAME
.Nm pthread_atfork
.Nd register handlers to be called before and after
.Fn fork
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fn pthread_atfork "void (*prepare)(void)" "void (*parent)(void)" "void (*child)(void)"
.Sh DESCRIPTION
The
.Fn pthread_atfork
function is used to register functions to be called before and after
.Fn fork
The
.Fa prepare 
handler is called before
.Fn fork ,
while the
.Fa parent
and
.Fa child
handlers are called after
.Fn fork
in the parent and child process, respectively.
.Fa prepare
handlers are called in reverse order of their registration, while
.Fa parent
and
.Fa child
handlers are called in the order in which they were registered. Any of the handlers may
be NULL.
.Pp
Remember: only async-cancel-safe functions are allowed on the child side of
.Fn fork
.Sh RETURN VALUES
If successful, the
.Fn pthread_atfork
function will return zero; otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
.Fn pthread_atfork
will fail if:
.Bl -tag -width Er
.It Bq Er ENOMEM
The system lacked the necessary resources to add another handler to the list.
.El
.Sh SEE ALSO
.Xr fork 2
.Sh STANDARDS
.Fn pthread_atfork
conforms to
.St -p1003.1-96 .
Commit	Line	Data
3d9156a7 A	1	.\" Copyright (c) 2004 Apple Computer, Inc.
	2	.\"
	3	.Dd August 12, 2004
	4	.Dt PTHREAD_ATFORK 3
	5	.Os
	6	.Sh NAME
	7	.Nm pthread_atfork
	8	.Nd register handlers to be called before and after
	9	.Fn fork
	10	.Sh SYNOPSIS
	11	.Fd #include <pthread.h>
	12	.Ft int
	13	.Fn pthread_atfork "void (prepare)(void)" "void (parent)(void)" "void (*child)(void)"
	14	.Sh DESCRIPTION
	15	The
	16	.Fn pthread_atfork
	17	function is used to register functions to be called before and after
	18	.Fn fork
	19	The
	20	.Fa prepare
	21	handler is called before
224c7076 A	22	.Fn fork ,
224c7076 A	23	while the
3d9156a7 A	24	.Fa parent
	25	and
	26	.Fa child
	27	handlers are called after
	28	.Fn fork
	29	in the parent and child process, respectively.
	30	.Fa prepare
	31	handlers are called in reverse order of their registration, while
	32	.Fa parent
	33	and
	34	.Fa child
	35	handlers are called in the order in which they were registered. Any of the handlers may
	36	be NULL.
	37	.Pp
	38	Remember: only async-cancel-safe functions are allowed on the child side of
	39	.Fn fork
	40	.Sh RETURN VALUES
	41	If successful, the
	42	.Fn pthread_atfork
	43	function will return zero; otherwise an error number will be returned to
	44	indicate the error.
	45	.Sh ERRORS
	46	.Fn pthread_atfork
	47	will fail if:
	48	.Bl -tag -width Er
	49	.It Bq Er ENOMEM
	50	The system lacked the necessary resources to add another handler to the list.
	51	.El
	52	.Sh SEE ALSO
	53	.Xr fork 2
	54	.Sh STANDARDS
	55	.Fn pthread_atfork
	56	conforms to
	57	.St -p1003.1-96 .