setjmp(9) [netbsd man page]

SETJMP(9)						   BSD Kernel Developer's Manual						 SETJMP(9)

NAME

     setjmp, longjmp -- non-local jumps

SYNOPSIS

     #include <machine/types.h>
     #include <sys/systm.h>

     int
     setjmp(label_t *label);

     void
     longjmp(label_t *label);

DESCRIPTION

     The setjmp() function saves its calling environment in label.  It returns zero on success.  The longjmp() function restores the environment
     saved by the most recent invocation of setjmp().  It returns so that kernel execution continues as if the corresponding invocation of the
     setjmp() had just returned.

     setjmp() and longjmp() are a machine-independent interface for machine-dependent implementations.

     These functions are primarily used by ddb(4).

SEE ALSO

     ddb(4)

BSD
								   May 23, 2002 							       BSD

SETJMP(3)							 Library functions							 SETJMP(3)

NAME

       setjmp, sigsetjmp - save stack context for non-local goto

SYNOPSIS

       #include <setjmp.h>

       int setjmp(jmp_buf env);
       int sigsetjmp(sigjmp_buf env, int savesigs);

DESCRIPTION

       setjmp()  and  longjmp()  are  useful  for dealing with errors and interrupts encountered in a low-level subroutine of a program.  setjmp()
       saves the stack context/environment in env for later use by longjmp().  The stack context will be invalidated if the function which  called
       setjmp() returns.

       sigsetjmp()  is	similar  to  setjmp().	 If savesigs is nonzero, the set of blocked signals is saved in env and will be restored if a sig-
       longjmp() is later performed with this env.

RETURN VALUE

       setjmp() and sigsetjmp() return 0 if returning directly, and non-zero when returning from longjmp() using the saved context.

CONFORMING TO

       POSIX, ISO 9899 (C99)

NOTES

       POSIX does not specify whether setjmp will save the signal context. (In SYSV it will not. In BSD4.3  it	will,  and  there  is  a  function
       _setjmp that will not.)	If you want to save signal masks, use sigsetjmp.

       setjmp() and sigsetjmp make programs hard to understand and maintain.  If possible an alternative should be used.

SEE ALSO

       longjmp(3), siglongjmp(3)

								    1997-03-02								 SETJMP(3)