1 /*

     2  * signals.h - header file for signals handling code

     3  *

     4  * This file is part of zsh, the Z shell.

     5  *

     6  * Copyright (c) 1992-1997 Paul Falstad

     7  * All rights reserved.

     8  *

     9  * Permission is hereby granted, without written agreement and without

    10  * license or royalty fees, to use, copy, modify, and distribute this

    11  * software and to distribute modified versions of this software for any

    12  * purpose, provided that the above copyright notice and the following

    13  * two paragraphs appear in all copies of this software.

    14  *

    15  * In no event shall Paul Falstad or the Zsh Development Group be liable

    16  * to any party for direct, indirect, special, incidental, or consequential

    17  * damages arising out of the use of this software and its documentation,

    18  * even if Paul Falstad and the Zsh Development Group have been advised of

    19  * the possibility of such damage.

    20  *

    21  * Paul Falstad and the Zsh Development Group specifically disclaim any

    22  * warranties, including, but not limited to, the implied warranties of

    23  * merchantability and fitness for a particular purpose.  The software

    24  * provided hereunder is on an "as is" basis, and Paul Falstad and the

    25  * Zsh Development Group have no obligation to provide maintenance,

    26  * support, updates, enhancements, or modifications.

    27  *

    28  */

    29 

    30 #define SIGNAL_HANDTYPE RETSIGTYPE (*)_((int))

    31 

    32 #ifndef HAVE_KILLPG

    33 # define killpg(pgrp,sig) kill(-(pgrp),sig)

    34 #endif

    35 

    36 #define SIGZERR   (SIGCOUNT+1)

    37 #define SIGDEBUG  (SIGCOUNT+2)

    38 #define VSIGCOUNT (SIGCOUNT+3)

    39 #define SIGEXIT    0

    40 

    41 #ifdef SV_BSDSIG

    42 # define SV_INTERRUPT SV_BSDSIG

    43 #endif

    44 

    45 /* If not a POSIX machine, then we create our *

    46  * own POSIX style signal sets functions.     */

    47 #ifndef POSIX_SIGNALS

    48 # define sigemptyset(s)    (*(s) = 0)

    49 # if NSIG == 32

    50 #  define sigfillset(s)    (*(s) = ~(sigset_t)0, 0)

    51 # else

    52 #  define sigfillset(s)    (*(s) = (1 << NSIG) - 1, 0)

    53 # endif

    54 # define sigaddset(s,n)    (*(s) |=  (1 << ((n) - 1)), 0)

    55 # define sigdelset(s,n)    (*(s) &= ~(1 << ((n) - 1)), 0)

    56 # define sigismember(s,n)  ((*(s) & (1 << ((n) - 1))) != 0)

    57 #endif   /* ifndef POSIX_SIGNALS */

    58  

    59 #define child_block()      signal_block(sigchld_mask)

    60 #define child_unblock()    signal_unblock(sigchld_mask)

    61 

    62 /* ignore a signal */

    63 #define signal_ignore(S)   signal(S, SIG_IGN)

    64 

    65 /* return a signal to it default action */

    66 #define signal_default(S)  signal(S, SIG_DFL)

    67 

    68 /* Use a circular queue to save signals caught during    *

    69  * critical sections of code.  You call queue_signals to *

    70  * start queueing, and unqueue_signals to process the    *

    71  * queue and stop queueing.  Since the kernel doesn't    *

    72  * queue signals, it is probably overkill for zsh to do  *

    73  * this, but it shouldn't hurt anything to do it anyway. */

    74 

    75 #define MAX_QUEUE_SIZE 128

    76 

    77 #define queue_signals()    (queueing_enabled++)

    78 

    79 #define run_queued_signals() do { \

    80     while (queue_front != queue_rear) {      /* while signals in queue */ \

    81 	sigset_t oset; \

    82 	queue_front = (queue_front + 1) % MAX_QUEUE_SIZE; \

    83 	oset = signal_setmask(signal_mask_queue[queue_front]); \

    84 	zhandler(signal_queue[queue_front]);  /* handle queued signal   */ \

    85 	signal_setmask(oset); \

    86     } \

    87 } while (0)

    88 

    89 #define unqueue_signals()  do { \

    90     DPUTS(!queueing_enabled, "BUG: unqueue_signals called but not queueing"); \

    91     if (!--queueing_enabled) run_queued_signals(); \

    92 } while (0)

    93 

    94 #define queue_signal_level() queueing_enabled

    95 

    96 #define dont_queue_signals() do { \

    97     queueing_enabled = 0; \

    98     run_queued_signals(); \

    99 } while (0)

   100 

   101 #define restore_queue_signals(q) (queueing_enabled = (q))

   102 

   103 /* Make some signal functions faster. */

   104 

   105 #ifdef POSIX_SIGNALS

   106 #define signal_block(S) \

   107     ((dummy_sigset1 = (S)), \

   108      sigprocmask(33, &dummy_sigset1, &dummy_sigset2), \

   109      dummy_sigset2)

   110 #else

   111 # ifdef BSD_SIGNALS

   112 #define signal_block(S) sigblock(S)

   113 # else

   114 extern sigset_t signal_block _((sigset_t));

   115 # endif  /* BSD_SIGNALS   */

   116 #endif   /* POSIX_SIGNALS */

   117 

   118 #ifdef POSIX_SIGNALS

   119 #define signal_unblock(S) \

   120     ((dummy_sigset1 = (S)), \

   121      sigprocmask(34, &dummy_sigset1, &dummy_sigset2), \

   122      dummy_sigset2)

   123 #else

   124 extern sigset_t signal_unblock _((sigset_t));

   125 #endif   /* POSIX_SIGNALS */