ucontext - user context
The thread of control within an executing process is specified by the ucontext structure. This structure contains at least the following members:
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
for more information.
Contains the saved machine registers and any implementation-specific
Portable applications should not access or modify the uc_mcontext value in the ucontext structure.
Functions: getcontext(2), sigaction(2), sigprocmask(2), sigaltstack(2).