Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
SETJMP(3)		     Library Functions Manual		       SETJMP(3)

NAME
     sigsetjmp,  siglongjmp, setjmp, longjmp, _setjmp, _longjmp, longjmperror --
     non-local jumps

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <setjmp.h>

     int
     sigsetjmp(sigjmp_buf env, int savemask);

     void
     siglongjmp(sigjmp_buf env, int val);

     int
     setjmp(jmp_buf env);

     void
     longjmp(jmp_buf env, int val);

     int
     _setjmp(jmp_buf env);

     void
     _longjmp(jmp_buf env, int val);

     void
     longjmperror(void);

DESCRIPTION
     The sigsetjmp(), setjmp(), and _setjmp() functions save their calling envi-
     ronment in env.  Each of these functions returns 0.

     The corresponding longjmp() functions  restore  the  environment  saved  by
     their  most  recent  respective invocations of the setjmp() function.  They
     then return so that program execution continues as if the corresponding in-
     vocation of the setjmp() call had just returned the value specified by val,
     instead of 0.

     Pairs of calls may be intermixed, i.e., both sigsetjmp()  and  siglongjmp()
     and  setjmp()  and  longjmp() combinations may be used in the same program,
     however, individual calls may not, e.g. the env argument  to  setjmp()  may
     not be passed to siglongjmp().

     The longjmp() routines may not be called after the routine which called the
     setjmp() routines returns.

     All  accessible  objects  have  values as of the time longjmp() routine was
     called, except that the values of objects of automatic  storage  invocation
     duration  that  do not have the volatile type and have been changed between
     the setjmp() invocation and longjmp() call are indeterminate.

     The setjmp()/longjmp()  pairs  save  and  restore	the  signal  mask  while
     _setjmp()/_longjmp()  pairs  save and restore only the register set and the
     stack.  (See sigprocmask(2).)

     The sigsetjmp()/siglongjmp() function pairs save  and  restore  the  signal
     mask  if the argument savemask is non-zero, otherwise only the register set
     and the stack are saved.

ERRORS
     If the contents of the env are corrupted, or correspond to  an  environment
     that  has already returned, the longjmp() routine calls the routine longjm-
     perror(3).   If  longjmperror()  returns  the  program  is   aborted   (see
     abort(3)).   The  default	version  of  longjmperror()  prints  the message
     "longjmp botch" to standard error and returns.  User  programs  wishing  to
     exit more gracefully should write their own versions of longjmperror().

SEE ALSO
     sigaction(2), sigaltstack(2), signal(3)

STANDARDS
     The   setjmp()   and  longjmp()  functions  conform  to  ISO/IEC  9899:1990
     ("ISO C90").  The sigsetjmp() and siglongjmp() functions  conform	to  IEEE
     Std 1003.1-1988 ("POSIX.1").

HISTORY
     The  setjmp()  and  longjmp()  functions first appeared in the Programmer's
     Workbench (PWB/UNIX).

FreeBSD ports 15.1		  April 2, 2022 		       SETJMP(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=sigsetjmp&sektion=3&manpath=FreeBSD+15.1-RELEASE+and+Ports>

home | help