minix/include/signal.h

/* The <signal.h> header defines all the ANSI and POSIX signals.
 * MINIX supports all the signals required by POSIX. They are defined below.
 * Some additional signals are also supported.
 */

#ifndef _SIGNAL_H
#define _SIGNAL_H

#ifndef _ANSI_H
#include <ansi.h>
#endif
#ifdef _POSIX_SOURCE
#ifndef _TYPES_H
#include <minix/types.h>
#endif
#endif

/* Here are types that are closely associated with signal handling. */
typedef int sig_atomic_t;

#ifdef _POSIX_SOURCE
#ifndef _SIGSET_T
#define _SIGSET_T
typedef unsigned long sigset_t;
#endif
#endif

/* Regular signals. */
#define SIGHUP             1	/* hangup */
#define SIGINT             2	/* interrupt (DEL) */
#define SIGQUIT            3	/* quit (ASCII FS) */
#define SIGILL             4	/* illegal instruction */
#define SIGTRAP            5	/* trace trap (not reset when caught) */
#define SIGABRT            6	/* IOT instruction */
#define SIGBUS             7	/* bus error */
#define SIGFPE             8	/* floating point exception */
#define SIGKILL            9	/* kill (cannot be caught or ignored) */
#define SIGUSR1           10	/* user defined signal # 1 */
#define SIGSEGV           11	/* segmentation violation */
#define SIGUSR2           12	/* user defined signal # 2 */
#define SIGPIPE           13	/* write on a pipe with no one to read it */
#define SIGALRM           14	/* alarm clock */
#define SIGTERM           15	/* software termination signal from kill */
#define SIGEMT		  16	/* EMT instruction */
#define SIGCHLD           17	/* child process terminated or stopped */
#define SIGWINCH    	  21	/* window size has changed */
#define SIGVTALRM         24	/* virtual alarm */
#define SIGPROF           25	/* profiler alarm */

/* POSIX requires the following signals to be defined, even if they are
 * not supported.  Here are the definitions, but they are not supported.
 */
#define SIGCONT           18	/* continue if stopped */
#define SIGSTOP           19	/* stop signal */
#define SIGTSTP           20	/* interactive stop signal */
#define SIGTTIN           22	/* background process wants to read */
#define SIGTTOU           23	/* background process wants to write */

#define _NSIG             26	/* highest signal number plus one */
#define NSIG             _NSIG

#ifdef _MINIX
#define SIGIOT             SIGABRT /* for people who speak PDP-11 */

/* MINIX specific signals. These signals are not used by user proceses, 
 * but meant to inform system processes, like the PM, about system events.
 * The order here determines the order signals are processed by system
 * processes in user-space. Higher-priority signals should be first.
 */
/* Signals delivered by a signal manager. */
#define SIGSNDELAY	  26	/* end of delay for signal delivery */

#define SIGS_FIRST	  SIGHUP      /* first system signal */
#define SIGS_LAST	  SIGSNDELAY   /* last system signal */
#define IS_SIGS(signo)    (signo>=SIGS_FIRST && signo<=SIGS_LAST)

/* Signals delivered by the kernel. */
#define SIGKMEM		  27	/* kernel memory request pending */
#define SIGKMESS   	  28	/* new kernel message */
#define SIGKSIGSM    	  29	/* kernel signal pending for signal manager */
#define SIGKSIG    	  30	/* kernel signal pending */

#define SIGK_FIRST	  SIGKMEM      /* first kernel signal */
#define SIGK_LAST	  SIGKSIG     /* last kernel signal */
#define IS_SIGK(signo)    (signo>=SIGK_FIRST && signo<=SIGK_LAST)

/* Termination signals for Minix system processes. */
#define SIGS_IS_LETHAL(sig) \
    (sig == SIGILL || sig == SIGBUS || sig == SIGFPE || sig == SIGSEGV \
    || sig == SIGEMT || sig == SIGABRT)
#define SIGS_IS_TERMINATION(sig) (SIGS_IS_LETHAL(sig) \
    || (sig == SIGKILL || sig == SIGPIPE))
#define SIGS_IS_STACKTRACE(sig) (SIGS_IS_LETHAL(sig) && sig != SIGABRT)

#endif

/* The sighandler_t type is not allowed unless _POSIX_SOURCE is defined. */
typedef void _PROTOTYPE( (*__sighandler_t), (int) );

/* Macros used as function pointers. */
#define SIG_ERR    ((__sighandler_t) -1)	/* error return */
#define SIG_DFL	   ((__sighandler_t)  0)	/* default signal handling */
#define SIG_IGN	   ((__sighandler_t)  1)	/* ignore signal */
#define SIG_HOLD   ((__sighandler_t)  2)	/* block signal */
#define SIG_CATCH  ((__sighandler_t)  3)	/* catch signal */

#ifdef _POSIX_SOURCE
struct sigaction {
  __sighandler_t sa_handler;	/* SIG_DFL, SIG_IGN, or pointer to function */
  sigset_t sa_mask;		/* signals to be blocked during handler */
  int sa_flags;			/* special flags */
};

/* Fields for sa_flags. */
#define SA_ONSTACK   0x0001	/* deliver signal on alternate stack */
#define SA_RESETHAND 0x0002	/* reset signal handler when signal caught */
#define SA_NODEFER   0x0004	/* don't block signal while catching it */
#define SA_RESTART   0x0008	/* automatic system call restart */
#define SA_SIGINFO   0x0010	/* extended signal handling */
#define SA_NOCLDWAIT 0x0020	/* don't create zombies */
#define SA_NOCLDSTOP 0x0040	/* don't receive SIGCHLD when child stops */

/* POSIX requires these values for use with sigprocmask(2). */
#define SIG_BLOCK          0	/* for blocking signals */
#define SIG_UNBLOCK        1	/* for unblocking signals */
#define SIG_SETMASK        2	/* for setting the signal mask */
#define SIG_INQUIRE        4	/* for internal use only */

/* codes for SIGFPE */
#define FPE_INTOVF      1      /* integer divide by zero */
#define FPE_INTDIV      2      /* integer overflow */
#define FPE_FLTDIV      3      /* floating-point divide by zero */
#define FPE_FLTOVF      4      /* floating-point overflow */
#define FPE_FLTUND      5      /* floating-point underflow */
#define FPE_FLTRES      6      /* floating-point inexact result */
#define FPE_FLTINV      7      /* floating-point invalid operation */
#define FPE_FLTSUB      8      /* subscript out of range */

typedef struct sigaltstack {
  void *ss_sp;
  int ss_flags;
  size_t ss_size;
} stack_t;

#define MINSIGSTKSZ	2048	/* Minimal stack size is 2k */

/* Fields for ss_flags */
#define SS_ONSTACK      1      /* Process is executing on an alternate stack */
#define SS_DISABLE      2      /* Alternate stack is disabled */


#endif	/* _POSIX_SOURCE */

/* POSIX and ANSI function prototypes. */
_PROTOTYPE( int raise, (int _sig)					);
_PROTOTYPE( __sighandler_t signal, (int _sig, __sighandler_t _func)	);

#ifdef _POSIX_SOURCE
_PROTOTYPE( int kill, (pid_t _pid, int _sig)				);
_PROTOTYPE( int killpg, (pid_t _pgrp, int _sig)				);
_PROTOTYPE( int sigaction,
    (int _sig, const struct sigaction *_act, struct sigaction *_oact)	);
_PROTOTYPE( int sigpending, (sigset_t *_set)				);
_PROTOTYPE( int sigprocmask,
	    (int _how, const sigset_t *_set, sigset_t *_oset)		);
_PROTOTYPE( int sigsuspend, (const sigset_t *_sigmask)			);

/* For the sigset functions, only use the library version with error
 * checking from user programs. System programs need to be able to use
 * nonstanard signals.
 */
#ifndef _SYSTEM
_PROTOTYPE( int sigaddset, (sigset_t *_set, int _sig)			);
_PROTOTYPE( int sigdelset, (sigset_t *_set, int _sig)			);
_PROTOTYPE( int sigemptyset, (sigset_t *_set)				);
_PROTOTYPE( int sigfillset, (sigset_t *_set)				);
_PROTOTYPE( int sigismember, (const sigset_t *_set, int _sig)		);
#else
#define sigaddset(set, sig)	((int) ((*(set) |= (1 << (sig))) && 0))
#define sigdelset(set, sig)	((int) ((*(set) &= ~(1 << (sig))) && 0))
#define sigemptyset(set)	((int) (*(set) = 0))
#define sigfillset(set)		((int) ((*(set) = ~0) && 0))
#define sigismember(set, sig)	((*(set) & (1 << (sig))) ? 1 : 0)
#endif

#endif

#endif /* _SIGNAL_H */