ucontext(5)                      UNIX System V                      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:

            ucontextt  uclink
            sigsett    ucsigmask
            stackt     ucstack
            mcontextt  ucmcontext

      uclink is a pointer to the context that to be resumed when this context
      returns.  If uclink is equal to 0, then this context is the main
      context, and the process exits when this context returns.

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

      ucstack defines the stack used by this context [see sigaltstack(2)].

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

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





















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