UCONTEXT(2)

NAME
ucontext - user context

SYNOPSIS
#include <ucontext.h>

DESCRIPTION
ucontext_t is a structure type which is used to describe the context of a thread of control within the execution of a process.

ucontext_t includes the following members:

    ucontext_t *  uc_link
    sigset_t      uc_sigmask
    stack_t       uc_stack
    mcontext_t    uc_mcontext

The uc_link member points to the context that will be resumed after the function specified when modifying a context using makecontext(3) has returned. If uc_link is a null pointer, then the context is the main context, and the process will exit with an exit status of 0 upon return.

The uc_sigmask member is the set of signals that are blocked when the context is activated. Further information can be found in sigprocmask(2).

The uc_stack member defines the stack used by the context. Further information can be found in sigaltstack(2).

The uc_mcontext member defines the machine state associated with the context; it may consist of general registers, floating point registers and other machine-specific information. Its description is beyond the scope of this manual page; portable applications should not access this structure member.

SEE ALSO
_exit(2), getcontext(2), setcontext(2), sigaltstack(2), sigprocmask(2), makecontext(3), swapcontext(3)

STANDARDS
The ucontext_t type conforms to xsh5.

HISTORY
The makecontext() and swapcontext() functions first appeared in AT&T UNIX.