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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH getcontext 2 "5 Feb 2001" "SunOS 5.11" "System Calls" .SH NAME getcontext, setcontext \- get and set current user context .SH SYNOPSIS .LP .nf #include \fBint\fR \fBgetcontext\fR(\fBucontext_t *\fR\fIucp\fR); .fi .LP .nf \fBint\fR \fBsetcontext\fR(\fBconst ucontext_t *\fR\fIucp\fR); .fi .SH DESCRIPTION .sp .LP The \fBgetcontext()\fR function initializes the structure pointed to by \fIucp\fR to the current user context of the calling process. The \fBucontext_t\fR type that \fIucp\fR points to defines the user context and includes the contents of the calling process' machine registers, the signal mask, and the current execution stack. .sp .LP The \fBsetcontext()\fR function restores the user context pointed to by \fIucp\fR. A successful call to \fBsetcontext()\fR does not return; program execution resumes at the point specified by the \fIucp\fR argument passed to \fBsetcontext()\fR. The \fIucp\fR argument should be created either by a prior call to \fBgetcontext()\fR, or by being passed as an argument to a signal handler. If the \fIucp\fR argument was created with \fBgetcontext()\fR, program execution continues as if the corresponding call of \fBgetcontext()\fR had just returned. If the \fIucp\fR argument was created with \fBmakecontext\fR(3C), program execution continues with the function passed to \fBmakecontext\fR(3C). When that function returns, the process continues as if after a call to \fBsetcontext()\fR with the \fIucp\fR argument that was input to \fBmakecontext\fR(3C). If the \fIucp\fR argument was passed to a signal handler, program execution continues with the program instruction following the instruction interrupted by the signal. If the \fBuc_link\fR member of the \fBucontext_t\fR structure pointed to by the \fIucp\fR argument is equal to 0, then this context is the main context, and the process will exit when this context returns. The effects of passing a \fIucp\fR argument obtained from any other source are unspecified. .SH RETURN VALUES .sp .LP On successful completion, \fBsetcontext()\fR does not return and \fBgetcontext()\fR returns \fB0\fR. Otherwise, \fB\(mi1\fR is returned. .SH ERRORS .sp .LP No errors are defined. .SH USAGE .sp .LP When a signal handler is executed, the current user context is saved and a new context is created. If the thread leaves the signal handler via \fBlongjmp\fR(3UCB), then it is unspecified whether the context at the time of the corresponding \fBsetjmp\fR(3UCB) call is restored and thus whether future calls to \fBgetcontext()\fR will provide an accurate representation of the current context, since the context restored by \fBlongjmp\fR(3UCB) may not contain all the information that \fBsetcontext()\fR requires. Signal handlers should use \fBsiglongjmp\fR(3C) instead. .sp .LP Portable applications should not modify or access the \fBuc_mcontext\fR member of \fBucontext_t\fR. A portable application cannot assume that context includes any process-wide static data, possibly including \fBerrno\fR. Users manipulating contexts should take care to handle these explicitly when required. .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) . \fBATTRIBUTE TYPE\fRATTRIBUTE VALUE _ Interface StabilityStandard .TE .SH SEE ALSO .sp .LP \fBsigaction\fR(2), \fBsigaltstack\fR(2), \fBsigprocmask\fR(2), \fBbsd_signal\fR(3C), \fBmakecontext\fR(3C), \fBsetjmp\fR(3UCB), \fBsigsetjmp\fR(3C), \fBucontext.h\fR(3HEAD), \fBattributes\fR(5), \fBstandards\fR(5)