GETCONTEXT(3) BSD Library Functions Manual GETCONTEXT(3)

NAME
     ggeettccoonntteexxtt, sseettccoonntteexxtt - get and set user thread context

LLIIBBRRAARRYY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##iinncclluuddee <>

     int
     ggeettccoonntteexxtt(ucontextt *ucp);

     int
     sseettccoonntteexxtt(const ucontextt *ucp);

DESCRIPTION
     The ggeettccoonntteexxtt() 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 sseettccoonntteexxtt().

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

     If ucp was initialized by ggeettccoonntteexxtt(), then execution continues as if
     the original ggeettccoonntteexxtt() 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->uclink determines what happens next: if ucp->uclink
     is NULL, the process exits; otherwise, sseettccoonntteexxtt(ucp->uclink) 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, ggeettccoonntteexxtt() returns zero and sseettccoonntteexxtt() does not
     return; otherwise -1 is returned.

EERRRROORRSS
     No errors are defined for ggeettccoonntteexxtt() or sseettccoonntteexxtt().

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

BSD                           September 10, 2002                           BSD