ucontext(5)                                                        ucontext(5)


NAME
     ucontext - user context

SYNOPSIS
     #include <ucontext.h>

DESCRIPTION
     The ucontext structure defines the context of a thread of control within
     an executing process.

     This structure includes at least the following members:

     ucontext_t *uc_link
     sigset_t    uc_sigmask
     stack_t     uc_stack
     mcontext_t  uc_mcontext

     uc_link is a pointer to the context that is to be resumed when this
     context returns.  If uc_link is equal to 0, then this context is the main
     context, and the process exits when this context returns.  The uc_link
     field is only meaningful for contexts created using makecontext.

     uc_sigmask defines the set of signals that are blocked when this context
     is active (see sigprocmask(2)).

     uc_stack defines the stack used by this context (see sigaltstack(2)).

     uc_mcontext contains the saved set of machine registers and any
     implementation specific context data.  Portable applications should not
     modify or access uc_mcontext.

SEE ALSO
     getcontext(2), sigaction(2), sigaltstack(2), sigprocmask(2),
     makecontext(3C)


                                                                        Page 1