[apple/libpthread.git] / man / 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.
The
.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
.Em Important :
only async-signal-safe functions are allowed on the child side of
.Fn fork .
See
.Xr sigaction 2
for details.
.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
f1a1da6c 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
	22	.Fn fork ,
	23	while the
	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	The
	31	.Fa prepare
	32	handlers are called in reverse order of their registration, while
	33	.Fa parent
	34	and
	35	.Fa child
	36	handlers are called in the order in which they were registered.
	37	Any of the handlers may be NULL.
	38	.Pp
	39	.Em Important :
	40	only async-signal-safe functions are allowed on the child side of
	41	.Fn fork .
	42	See
	43	.Xr sigaction 2
	44	for details.
	45	.Sh RETURN VALUES
	46	If successful, the
	47	.Fn pthread_atfork
	48	function will return zero; otherwise an error number will be returned to
	49	indicate the error.
	50	.Sh ERRORS
	51	.Fn pthread_atfork
	52	will fail if:
	53	.Bl -tag -width Er
	54	.It Bq Er ENOMEM
	55	The system lacked the necessary resources to add another handler to the list.
	56	.El
	57	.Sh SEE ALSO
	58	.Xr fork 2
	59	.Sh STANDARDS
	60	.Fn pthread_atfork
	61	conforms to
	62	.St -p1003.1-96 .