[apple/libplatform.git] / man / ucontext.3

.\" Copyright (c) 2002 Packet Design, LLC.
.\" All rights reserved.
.\"
.\" Subject to the following obligations and disclaimer of warranty,
.\" use and redistribution of this software, in source or object code
.\" forms, with or without modifications are expressly permitted by
.\" Packet Design; provided, however, that:
.\"
.\"    (i)  Any and all reproductions of the source or object code
.\"         must include the copyright notice above and the following
.\"         disclaimer of warranties; and
.\"    (ii) No rights are granted, in any manner or form, to use
.\"         Packet Design trademarks, including the mark "PACKET DESIGN"
.\"         on advertising, endorsements, or otherwise except as such
.\"         appears in the above copyright notice or in the software.
.\"
.\" THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
.\" TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
.\" REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
.\" THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
.\" WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
.\" OR NON-INFRINGEMENT.  PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
.\" OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
.\" OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
.\" RELIABILITY OR OTHERWISE.  IN NO EVENT SHALL PACKET DESIGN BE
.\" LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
.\" OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
.\" DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
.\" USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
.\" LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
.\" THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
.\" THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD: src/lib/libc/gen/ucontext.3,v 1.3 2004/07/03 22:30:08 ru Exp $
.\"
.Dd September 10, 2002
.Dt UCONTEXT 3
.Os
.Sh NAME
.Nm ucontext
.Nd user thread context
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ucontext.h
.Sh DESCRIPTION
The
.Vt ucontext_t
type is a structure type suitable for holding the context for a user
thread of execution.
A thread's context includes its stack, saved registers, and list of
blocked signals.
.Pp
The
.Vt ucontext_t
structure contains at least these fields:
.Pp
.Bl -tag -width ".Va mcontext_t\ \ uc_mcontext" -offset 3n -compact
.It Va "ucontext_t *uc_link"
context to assume when this one returns
.It Va "sigset_t uc_sigmask"
signals being blocked
.It Va "stack_t uc_stack"
stack area
.It Va "mcontext_t uc_mcontext"
saved registers
.El
.Pp
The
.Va uc_link
field points to the context to resume when this context's entry point
function returns.
If
.Va uc_link
is equal to
.Dv NULL ,
then the process exits when this context returns.
.Pp
The
.Va uc_mcontext
field is machine-dependent and should be treated as opaque by
portable applications.
.Pp
The following functions are defined to manipulate
.Vt ucontext_t
structures:
.Pp
.Bl -item -offset 3n -compact
.It
.Ft int
.Fn getcontext "ucontext_t *" ;
.It
.Ft int
.Fn setcontext "const ucontext_t *" ;
.It
.Ft void
.Fn makecontext "ucontext_t *" "void \*[lp]*\*[rp]\*[lp]void\*[rp]" int ... ;
.It
.Ft int
.Fn swapcontext "ucontext_t *" "const ucontext_t *" ;
.El
.Sh SEE ALSO
.Xr sigaltstack 2 ,
.Xr getcontext 3 ,
.Xr makecontext 3
Commit	Line	Data
ada7c492 A	1	.\" Copyright (c) 2002 Packet Design, LLC.
	2	.\" All rights reserved.
	3	.\"
	4	.\" Subject to the following obligations and disclaimer of warranty,
	5	.\" use and redistribution of this software, in source or object code
	6	.\" forms, with or without modifications are expressly permitted by
	7	.\" Packet Design; provided, however, that:
	8	.\"
	9	.\" (i) Any and all reproductions of the source or object code
	10	.\" must include the copyright notice above and the following
	11	.\" disclaimer of warranties; and
	12	.\" (ii) No rights are granted, in any manner or form, to use
	13	.\" Packet Design trademarks, including the mark "PACKET DESIGN"
	14	.\" on advertising, endorsements, or otherwise except as such
	15	.\" appears in the above copyright notice or in the software.
	16	.\"
	17	.\" THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
	18	.\" TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
	19	.\" REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
	20	.\" THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
	21	.\" WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
	22	.\" OR NON-INFRINGEMENT. PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
	23	.\" OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
	24	.\" OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
	25	.\" RELIABILITY OR OTHERWISE. IN NO EVENT SHALL PACKET DESIGN BE
	26	.\" LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
	27	.\" OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
	28	.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
	29	.\" DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
	30	.\" USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
	31	.\" LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	32	.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
	33	.\" THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
	34	.\" THE POSSIBILITY OF SUCH DAMAGE.
	35	.\"
	36	.\" $FreeBSD: src/lib/libc/gen/ucontext.3,v 1.3 2004/07/03 22:30:08 ru Exp $
	37	.\"
	38	.Dd September 10, 2002
	39	.Dt UCONTEXT 3
	40	.Os
	41	.Sh NAME
	42	.Nm ucontext
	43	.Nd user thread context
	44	.Sh LIBRARY
	45	.Lb libc
	46	.Sh SYNOPSIS
	47	.In ucontext.h
	48	.Sh DESCRIPTION
	49	The
	50	.Vt ucontext_t
	51	type is a structure type suitable for holding the context for a user
	52	thread of execution.
	53	A thread's context includes its stack, saved registers, and list of
	54	blocked signals.
	55	.Pp
	56	The
	57	.Vt ucontext_t
	58	structure contains at least these fields:
	59	.Pp
	60	.Bl -tag -width ".Va mcontext_t\ \ uc_mcontext" -offset 3n -compact
	61	.It Va "ucontext_t *uc_link"
	62	context to assume when this one returns
	63	.It Va "sigset_t uc_sigmask"
	64	signals being blocked
65	.It Va "stack_t uc_stack"
66	stack area
67	.It Va "mcontext_t uc_mcontext"
68	saved registers
69	.El
70	.Pp
71	The
72	.Va uc_link
73	field points to the context to resume when this context's entry point
74	function returns.
75	If
76	.Va uc_link
77	is equal to
78	.Dv NULL ,
79	then the process exits when this context returns.
80	.Pp
81	The
82	.Va uc_mcontext
83	field is machine-dependent and should be treated as opaque by
84	portable applications.
85	.Pp
86	The following functions are defined to manipulate
87	.Vt ucontext_t
88	structures:
89	.Pp
90	.Bl -item -offset 3n -compact
91	.It
92	.Ft int
93	.Fn getcontext "ucontext_t *" ;
94	.It
95	.Ft int
96	.Fn setcontext "const ucontext_t *" ;
97	.It
98	.Ft void
99	.Fn makecontext "ucontext_t " "void \[lp]\[rp]\[lp]void\[rp]" int ... ;
100	.It
101	.Ft int
102	.Fn swapcontext "ucontext_t " "const ucontext_t " ;
103	.El
104	.Sh SEE ALSO
105	.Xr sigaltstack 2 ,
106	.Xr getcontext 3 ,
107	.Xr makecontext 3