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UCONTEXT(2)		    BSD	System Calls Manual		   UCONTEXT(2)

NAME
     ucontext -- user context

SYNOPSIS
     #include <ucontext.h>

DESCRIPTION
     The ucontext_t is a structure type	which is used to describe the context
     of	a thread of control within the execution of a process.	A thread's
     context includes its stack, saved registers, and list of blocked signals.

     The ucontext_t structure 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 re-
     turned.  If uc_link is a NULL pointer, then the context is	the main con-
     text, 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 in-
     formation can be found in sigaltstack(2).

     The uc_mcontext member defines the	machine	state associated with the con-
     text; 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 struc-
     ture member.

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

STANDARDS
     The ucontext_t type conforms to X/Open System Interfaces and Headers
     Issue 5 ("XSH5") and IEEE Std 1003.1-2001 ("POSIX.1").  The IEEE Std
     1003.1-2008 ("POSIX.1") revision removed the ucontext_t from the specifi-
     cation.

BSD				April 29, 2010				   BSD

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | STANDARDS

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