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GETCONTEXT(3)	       FreeBSD Library Functions Manual		 GETCONTEXT(3)

NAME
     getcontext, setcontext -- get and set user	thread context

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <ucontext.h>

     int
     getcontext(ucontext_t *ucp);

     int
     setcontext(const ucontext_t *ucp);

DESCRIPTION
     The getcontext() function saves the current thread's execution context in
     the structure pointed to by ucp.  This saved context may then later be
     restored by calling setcontext().

     The setcontext() function makes a previously saved	thread context the
     current thread context, i.e., the current context is lost and
     setcontext() does not return.  Instead, execution continues in the	con-
     text specified by ucp, which must have been previously initialized	by a
     call to getcontext(), makecontext(3), or by being passed as an argument
     to	a signal handler (see sigaction(2)).

     If	ucp was	initialized by getcontext(), then execution continues as if
     the original getcontext() call had	just returned (again).

     If	ucp was	initialized by makecontext(3), execution continues with	the
     invocation	of the function	specified to makecontext(3).  When that	func-
     tion returns, ucp-_uc_link	determines what	happens	next: if ucp-_uc_link
     is	NULL, the process exits; otherwise, setcontext(ucp-_uc_link) is
     implicitly	invoked.

     If	ucp was	initialized by the invocation of a signal handler, execution
     continues at the point the	thread was interrupted by the signal.

RETURN VALUES
     If	successful, getcontext() returns zero and setcontext() does not
     return; otherwise -1 is returned.

ERRORS
     No	errors are defined for getcontext() or setcontext().

SEE ALSO
     sigaction(2), sigaltstack(2), makecontext(3), ucontext(3)

FreeBSD	10.1		      September	10, 2002		  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO

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