+++ /dev/null
-.\" 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/getcontext.3,v 1.3 2004/12/03 14:10:04 rse Exp $
-.\"
-.Dd September 10, 2002
-.Dt GETCONTEXT 3
-.Os
-.Sh NAME
-.Nm getcontext , setcontext
-.Nd get and set user thread context
-.Sh LIBRARY
-.Lb libc
-.Sh SYNOPSIS
-.In ucontext.h
-.Ft int
-.Fn getcontext "ucontext_t *ucp"
-.Ft int
-.Fn setcontext "const ucontext_t *ucp"
-.Sh DESCRIPTION
-The
-.Fn getcontext
-function
-saves the current thread's execution context in the structure pointed to by
-.Fa ucp .
-This saved context may then later be restored by calling
-.Fn setcontext .
-.Pp
-The
-.Fn setcontext
-function
-makes a previously saved thread context the current thread context, i.e.,
-the current context is lost and
-.Fn setcontext
-does not return.
-Instead, execution continues in the context specified by
-.Fa ucp ,
-which must have been previously initialized by a call to
-.Fn getcontext ,
-.Xr makecontext 3 ,
-or by being passed as an argument to a signal handler (see
-.Xr sigaction 2 ) .
-.Pp
-If
-.Fa ucp
-was initialized by
-.Fn getcontext ,
-then execution continues as if the original
-.Fn getcontext
-call had just returned (again).
-.Pp
-If
-.Fa ucp
-was initialized by
-.Xr makecontext 3 ,
-execution continues with the invocation of the function specified to
-.Xr makecontext 3 .
-When that function returns,
-.Fa "ucp->uc_link"
-determines what happens next:
-if
-.Fa "ucp->uc_link"
-is
-.Dv NULL ,
-the process exits;
-otherwise,
-.Fn setcontext "ucp->uc_link"
-is implicitly invoked.
-.Pp
-If
-.Fa ucp
-was initialized by the invocation of a signal handler, execution continues
-at the point the thread was interrupted by the signal.
-.Sh RETURN VALUES
-If successful,
-.Fn getcontext
-returns zero and
-.Fn setcontext
-does not return; otherwise \-1 is returned.
-.Sh ERRORS
-No errors are defined for
-.Fn getcontext
-or
-.Fn setcontext .
-.Sh SEE ALSO
-.Xr sigaction 2 ,
-.Xr sigaltstack 2 ,
-.Xr makecontext 3 ,
-.Xr ucontext 3
projects / apple / libc.git / blobdiff