/*
 * Copyright (c) 1998-2001 Sendmail, Inc. and its suppliers.
 *      All rights reserved.
 * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
 * Copyright (c) 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 *      $Id: signal.h,v 1.16 2001/07/20 19:48:21 gshapiro Exp $
 */

/*
**  SIGNAL.H -- libsm (and sendmail) signal facilities
**              Extracted from sendmail/conf.h and focusing
**              on signal configuration.
*/

#ifndef SM_SIGNAL_H
#define SM_SIGNAL_H 1

#include <sys/types.h>
#include <limits.h>
#include <signal.h>
#include <sm/cdefs.h>
#include <sm/conf.h>

/*
**  Critical signal sections
*/

#define PEND_SIGHUP     0x0001
#define PEND_SIGINT     0x0002
#define PEND_SIGTERM    0x0004
#define PEND_SIGUSR1    0x0008

#define ENTER_CRITICAL()        InCriticalSection++

#define LEAVE_CRITICAL()                                                \
do                                                                      \
{                                                                       \
        if (InCriticalSection > 0)                                      \
                InCriticalSection--;                                    \
} while (0)

#define CHECK_CRITICAL(sig)                                             \
do                                                                      \
{                                                                       \
        if (InCriticalSection > 0 && (sig) != 0)                        \
        {                                                               \
                pend_signal((sig));                                     \
                return SIGFUNC_RETURN;                                  \
        }                                                               \
} while (0)

/* variables */
extern unsigned int     volatile InCriticalSection;     /* >0 if in critical section */
extern int              volatile PendingSignal; /* pending signal to resend */

/* functions */
extern void             pend_signal __P((int));

/* reset signal in case System V semantics */
#ifdef SYS5SIGNALS
# define FIX_SYSV_SIGNAL(sig, handler)                                  \
{                                                                       \
        if ((sig) != 0)                                                 \
                (void) sm_signal((sig), (handler));                     \
}
#else /* SYS5SIGNALS */
# define FIX_SYSV_SIGNAL(sig, handler)  { /* EMPTY */ }
#endif /* SYS5SIGNALS */

extern void             sm_allsignals __P((bool));
extern int              sm_blocksignal __P((int));
extern int              sm_releasesignal __P((int));
extern sigfunc_t        sm_signal __P((int, sigfunc_t));
extern SIGFUNC_DECL     sm_signal_noop __P((int));
#endif /* SM_SIGNAL_H */