ucontext(3) [freebsd man page]

UCONTEXT(3)						   BSD Library Functions Manual 					       UCONTEXT(3)

NAME

     ucontext -- user thread context

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <ucontext.h>

DESCRIPTION

     The ucontext_t type is a structure type suitable for holding the context for a user thread of execution.  A thread's context includes its
     stack, saved registers, and list of blocked signals.

     The ucontext_t structure contains at least these fields:

	ucontext_t *uc_link	 context to assume when this one returns
	sigset_t uc_sigmask	 signals being blocked
	stack_t uc_stack	 stack area
	mcontext_t uc_mcontext	 saved registers

     The uc_link field points to the context to resume when this context's entry point function returns.  If uc_link is equal to NULL, then the
     process exits when this context returns.

     The uc_mcontext field is machine-dependent and should be treated as opaque by portable applications.

     The following functions are defined to manipulate ucontext_t structures:

	int getcontext(ucontext_t *);
	ucontext_t * getcontextx(void);
	int setcontext(const ucontext_t *);
	void makecontext(ucontext_t *, void (*)(void), int, ...);
	int swapcontext(ucontext_t *, const ucontext_t *);

SEE ALSO

     sigaltstack(2), getcontext(3), getcontextx(3), makecontext(3)

BSD
								September 10, 2002							       BSD

ucontext.h(3HEAD)						      Headers							 ucontext.h(3HEAD)

NAME

       ucontext.h, ucontext - user context

SYNOPSIS

       #include <ucontext.h>

DESCRIPTION

       The  <ucontext.h> header defines the ucontext_t type as a structure that includes at least the following members:

	 ucontext_t  uc_link
	 sigset_t    uc_sigmask
	 stack_t     uc_stack
	 mcontext_t  uc_mcontext

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

       The uc_sigmask member defines the set of signals that are blocked when this context is active. See sigprocmask(2).

       The uc_stack member defines the stack used by this context. See sigaltstack(2).

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

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       getcontext(2), sigaction(2), sigaltstack(2), sigprocmask(2), makecontext(3C), attributes(5), standards(5)

SunOS 5.11							    30 Aug 2002 						 ucontext.h(3HEAD)