osf1 man page for ucontext

ucontext(5)							File Formats Manual						       ucontext(5)

NAME
       ucontext - user context

SYNOPSIS
       #include <ucontext.h>

DESCRIPTION
       The  thread  of control within an executing process is specified by the ucontext structure.  This structure contains at least the following
       members:

       ucontext_t  uc_link
	      sigset_t	  uc_sigmask
	      stack_t	  uc_stack
	      mcontext_t  uc_mcontext

       The values for each member is as follows: Points to the context that is to continue when this context returns. If uc_link is equal to  zero
       (0),  this  is  the main context, and the process exits when this context returns.  Specifies the set of signals that are blocked when this
       context is active.  See sigprocmask(2) for more information.  Specifies the stack used by this context.	See sigaltstack(2) for more infor-
       mation.	Contains the saved machine registers and any implementation-specific context data.

RESTRICTIONS
       Portable applications should not access or modify the uc_mcontext value in the ucontext structure.

SEE ALSO
       Functions: getcontext(2), sigaction(2), sigprocmask(2), sigaltstack(2).

																       ucontext(5)