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428
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1 /* Handling asynchronous signals.
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2 Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
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2518
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3 Copyright (C) 1995, 1996, 2001, 2002, 2004 Ben Wing.
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428
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4
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5 This file is part of XEmacs.
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6
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7 XEmacs is free software; you can redistribute it and/or modify it
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8 under the terms of the GNU General Public License as published by the
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9 Free Software Foundation; either version 2, or (at your option) any
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10 later version.
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11
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12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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15 for more details.
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16
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17 You should have received a copy of the GNU General Public License
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18 along with XEmacs; see the file COPYING. If not, write to
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19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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20 Boston, MA 02111-1307, USA. */
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21
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22 /* Synched up with: Not synched with FSF. Split out of keyboard.c. */
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23
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24 #include <config.h>
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25 #include "lisp.h"
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26
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27 #include "console.h"
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872
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28 #include "device-impl.h"
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428
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29 #include "events.h" /* for signal_fake_event() */
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872
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30 #include "frame-impl.h"
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593
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31 #include "process.h"
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611
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32
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428
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33 #include "sysdep.h"
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611
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34 #include "sysfile.h"
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428
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35 #include "syssignal.h"
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36 #include "systime.h"
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37
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38 /* Set to 1 when a quit-check signal (either a SIGIO interrupt or
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39 the asynch. timeout for poll-for-quit) occurs. The QUITP
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40 macro may look at this. */
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41 volatile int quit_check_signal_happened;
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42
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43 /* Count of the number of times a quit-check signal has occurred.
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44 Some stuff in event-Xt.c looks at this. */
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45 volatile int quit_check_signal_tick_count;
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46
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47 /* Set to 1 when a SIGINT (or SIGQUIT) interrupt is processed.
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48 maybe_read_quit_event() looks at this. */
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49 volatile int sigint_happened;
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50
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51 /* Set to 1 when an asynch. timeout signal occurs. */
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593
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52 static volatile int async_timeout_happened;
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53
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54 /* Set to 1 when a multiple of SLOWED_DOWN_INTERRUPTS_SECS elapses,
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55 after slow_down_interrupts() is called. */
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56 static volatile int slowed_interrupt_timeout_happened;
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428
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57
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58 /* This is used to synchronize setting the waiting_for_user_input_p
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59 flag. */
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593
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60 static volatile int async_timeout_happened_while_emacs_was_blocking;
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428
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61
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62 /* See check_quit() for when this is set. */
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63 int dont_check_for_quit;
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64
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593
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65 static int poll_for_quit_id;
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66 static int poll_for_sigchld_id;
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428
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67
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68 /* This variable is used to communicate to a lisp
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69 process-filter/sentinel/asynchronous callback (via the function
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70 Fwaiting_for_user_input_p below) whether XEmacs was waiting for
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71 user-input when that process-filter was called. */
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72 static int waiting_for_user_input_p;
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73
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74 static int interrupts_slowed_down;
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75
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76 #define SLOWED_DOWN_INTERRUPTS_SECS 15
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77 #define NORMAL_QUIT_CHECK_TIMEOUT_MSECS 250
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78 #define NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS 250
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79
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80 /* Used so that signals can break out of system calls that aren't
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81 naturally interruptible. */
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82
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83 JMP_BUF break_system_call_jump;
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84 volatile int can_break_system_calls;
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85
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593
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86 static SIGTYPE alarm_signal (int signo);
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87
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88
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428
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89
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90 /**********************************************************************/
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91 /* Asynchronous timeout functions */
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92 /**********************************************************************/
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93
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593
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94 /* See the comment in event-stream.c, under major heading "Timeouts",
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95 for the difference between low-level (one-shot) and high-level
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96 (periodic/resignaling) timeouts. */
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97
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428
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98 /* The pending timers are stored in an ordered list, where the first timer
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99 on the list is the first one to fire. Times recorded here are
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100 absolute. */
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101 static struct low_level_timeout *async_timer_queue;
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102
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103 /* Nonzero means async timers are temporarily suppressed. */
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104 static int async_timer_suppress_count;
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105
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106 static void
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107 set_one_shot_timer (EMACS_TIME interval)
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108 {
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109 #ifdef HAVE_SETITIMER
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110 struct itimerval it;
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111 it.it_value = interval;
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112 EMACS_SET_SECS_USECS (it.it_interval, 0, 0);
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611
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113 qxe_setitimer (ITIMER_REAL, &it, 0);
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428
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114 #else
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115 int secs;
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116 EMACS_TIME_TO_INT (interval, secs);
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117 alarm (secs);
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118 #endif
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119 }
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120
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121 static void
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122 reset_interval_timer (void)
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123 {
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124 EMACS_TIME interval;
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125
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126 /* Get the interval to set. If an interval is available,
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127 make sure it's not zero (this is a valid return, but it will
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128 cause the timer to get disabled, so convert it to a very short
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129 time). */
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130 if (get_low_level_timeout_interval (async_timer_queue, &interval))
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131 {
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132 if (EMACS_SECS (interval) == 0 && EMACS_USECS (interval) == 0)
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133 EMACS_SET_USECS (interval, 1);
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134 }
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135 else
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136 /* A time of 0 means "disable". */
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137 EMACS_SET_SECS_USECS (interval, 0, 0);
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138
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139 set_one_shot_timer (interval);
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140 }
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141
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142
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143 static void
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144 init_async_timeouts (void)
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145 {
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613
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146 set_timeout_signal (SIGALRM, alarm_signal);
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428
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147 async_timer_suppress_count = 0;
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148 }
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149
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150 /* Turn off async timeouts. */
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151
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152 static void
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153 stop_async_timeouts (void)
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154 {
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155 if (async_timer_suppress_count == 0)
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156 {
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157 /* If timer was on, turn it off. */
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158 EMACS_TIME thyme;
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159 EMACS_SET_SECS_USECS (thyme, 0, 0);
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160 set_one_shot_timer (thyme);
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161 }
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162 async_timer_suppress_count++;
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163 }
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164
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165 /* Turn on async timeouts again. */
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166
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167 static void
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168 start_async_timeouts (void)
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169 {
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170 assert (async_timer_suppress_count > 0);
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171 async_timer_suppress_count--;
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172 if (async_timer_suppress_count == 0)
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173 {
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174 /* Some callers turn off async timeouts and then use the alarm
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175 for their own purposes; so reinitialize everything. */
|
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613
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176 set_timeout_signal (SIGALRM, alarm_signal);
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428
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177 reset_interval_timer ();
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178 }
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179 }
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180
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593
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181 static void
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182 handle_async_timeout_signal (void)
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428
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183 {
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593
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184 int interval_id;
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185 int wakeup_id;
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186 Lisp_Object fun, arg;
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771
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187 /* Avoid any possibility of GC during QUIT */
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188 int specco = begin_gc_forbidden ();
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593
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189
|
|
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190 /* No checks for Vinhibit_quit here or anywhere else in this file!!!
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191 Otherwise critical quit will not work right.
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771
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192 The only check for Vinhibit_quit is in QUIT itself.
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193
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194 (#### ???? I don't quite understand this comment.) */
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593
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195 interval_id = pop_low_level_timeout (&async_timer_queue, 0);
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196
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197 reset_interval_timer ();
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198 if (async_timeout_happened_while_emacs_was_blocking)
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199 {
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200 async_timeout_happened_while_emacs_was_blocking = 0;
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201 waiting_for_user_input_p = 1;
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202 }
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203
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204 wakeup_id = event_stream_resignal_wakeup (interval_id, 1, &fun, &arg);
|
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428
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205
|
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593
|
206 if (wakeup_id == poll_for_quit_id)
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207 {
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208 quit_check_signal_happened = 1;
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209 quit_check_signal_tick_count++;
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210 }
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211 else if (wakeup_id == poll_for_sigchld_id)
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428
|
212 {
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593
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213 kick_status_notify ();
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428
|
214 }
|
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593
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215 else
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216 /* call1 GC-protects its arguments */
|
|
853
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217 call1_trapping_problems ("Error in asynchronous timeout callback",
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|
|
218 fun, arg, INHIBIT_GC);
|
|
593
|
219
|
|
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220 waiting_for_user_input_p = 0;
|
|
771
|
221
|
|
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222 unbind_to (specco);
|
|
593
|
223 }
|
|
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224
|
|
|
225 /* The following two functions are the external interface onto
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|
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226 creating/deleting asynchronous interval timeouts, and are
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|
|
227 called by event-stream.c. We call back to event-stream.c using
|
|
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228 event_stream_resignal_wakeup(), when an interval goes off. */
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|
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229
|
|
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230 int
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|
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231 signal_add_async_interval_timeout (EMACS_TIME thyme)
|
|
|
232 {
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|
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233 int id = add_low_level_timeout (&async_timer_queue, thyme);
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234
|
|
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235 /* If this timeout is at the head of the queue, then we need to
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236 set the timer right now for this timeout. Otherwise, things
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|
|
237 are fine as-is; after the timers ahead of us are signalled,
|
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238 the timer will be set for us. */
|
|
|
239
|
|
|
240 if (async_timer_queue->id == id)
|
|
|
241 reset_interval_timer ();
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|
|
242
|
|
|
243 return id;
|
|
428
|
244 }
|
|
|
245
|
|
|
246 void
|
|
593
|
247 signal_remove_async_interval_timeout (int id)
|
|
428
|
248 {
|
|
593
|
249 int first = (async_timer_queue && async_timer_queue->id == id);
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|
|
250 remove_low_level_timeout (&async_timer_queue, id);
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|
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251
|
|
|
252 /* If we removed the timeout from the head of the queue, then
|
|
|
253 we need to reset the interval timer right now. */
|
|
|
254 if (first)
|
|
|
255 reset_interval_timer ();
|
|
428
|
256 }
|
|
|
257
|
|
593
|
258 /* If alarm() gets called when polling isn't disabled, it will mess up
|
|
|
259 the asynchronous timeouts, and then C-g checking won't work again.
|
|
|
260 Some libraries call alarm() directly, so we override the standard
|
|
2500
|
261 library's alarm() and ABORT() if the caller of the library function
|
|
593
|
262 didn't wrap in stop_interrupts()/start_interrupts().
|
|
428
|
263
|
|
593
|
264 NOTE: We could potentially avoid the need to wrap by adding a
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|
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265 one-shot timeout to simulate the alarm(), smashing our signal
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|
|
266 handler back into place, and calling the library function when the
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|
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267 alarm goes off. But do we want to? We're not going to gain the
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|
|
268 ability to C-g out of library functions this way (unless we forcibly
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|
|
269 longjmp() out of a signal handler, which is likely to lead to a
|
|
|
270 crash). --ben */
|
|
428
|
271
|
|
|
272 #ifdef HAVE_SETITIMER
|
|
611
|
273
|
|
428
|
274 unsigned int
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|
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275 alarm (unsigned int howlong)
|
|
|
276 {
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|
|
277 struct itimerval old_it, new_it;
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|
|
278
|
|
|
279 assert (async_timer_suppress_count > 0);
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|
|
280
|
|
|
281 new_it.it_value.tv_sec = howlong;
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|
|
282 new_it.it_value.tv_usec = 0;
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|
|
283 new_it.it_interval.tv_sec = 0;
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|
|
284 new_it.it_interval.tv_usec = 0;
|
|
611
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285 qxe_setitimer (ITIMER_REAL, &new_it, &old_it);
|
|
428
|
286
|
|
|
287 /* Never return zero if there was a timer outstanding. */
|
|
|
288 return old_it.it_value.tv_sec + (old_it.it_value.tv_usec > 0 ? 1 : 0);
|
|
|
289 }
|
|
611
|
290
|
|
|
291 int
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|
|
292 qxe_setitimer (int kind, const struct itimerval *itnew,
|
|
|
293 struct itimerval *itold)
|
|
|
294 {
|
|
1315
|
295 #ifdef WIN32_ANY
|
|
611
|
296 /* setitimer() does not exist on native MS Windows, and appears broken
|
|
617
|
297 on Cygwin. See win32.c.
|
|
|
298
|
|
|
299 We are emulating the Unix98 setitimer() function, as found in its
|
|
|
300 incarnations on modern versions of Unix. Note however that in
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|
|
301 the win32.c version, ITNEW and ITOLD must be equal if both are
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|
|
302 non-zero, due to limitations in the underlying multimedia-timer
|
|
|
303 API. */
|
|
611
|
304 return mswindows_setitimer (kind, itnew, itold);
|
|
|
305 #else
|
|
617
|
306 /* YUCK! glibc defines setitimer's first argument as
|
|
|
307 enum __itimer_which, not int, which causes compile errors if
|
|
|
308 we call setitimer() in the obvious way. */
|
|
|
309 switch (kind)
|
|
|
310 {
|
|
|
311 case ITIMER_REAL: return setitimer (ITIMER_REAL, itnew, itold);
|
|
|
312 case ITIMER_VIRTUAL: return setitimer (ITIMER_VIRTUAL, itnew, itold);
|
|
|
313 case ITIMER_PROF: return setitimer (ITIMER_PROF, itnew, itold);
|
|
2500
|
314 default: ABORT (); return 0;
|
|
617
|
315 }
|
|
428
|
316 #endif
|
|
611
|
317 }
|
|
|
318
|
|
|
319 #endif /* HAVE_SETITIMER */
|
|
|
320
|
|
613
|
321 signal_handler_t
|
|
|
322 set_timeout_signal (int signal_number, signal_handler_t action)
|
|
|
323 {
|
|
|
324 #ifdef CYGWIN_BROKEN_SIGNALS
|
|
|
325 return mswindows_sigset (signal_number, action);
|
|
|
326 #else
|
|
|
327 return EMACS_SIGNAL (signal_number, action);
|
|
|
328 #endif
|
|
|
329 }
|
|
428
|
330
|
|
|
331 DEFUN ("waiting-for-user-input-p", Fwaiting_for_user_input_p, 0, 0, 0, /*
|
|
|
332 Return non-nil if XEmacs is waiting for input from the user.
|
|
|
333 This is intended for use by asynchronous timeout callbacks and by
|
|
|
334 asynchronous process output filters and sentinels (not yet implemented
|
|
|
335 in XEmacs). It will always be nil if XEmacs is not inside of
|
|
|
336 an asynchronous timeout or process callback.
|
|
|
337 */
|
|
|
338 ())
|
|
|
339 {
|
|
|
340 return waiting_for_user_input_p ? Qt : Qnil;
|
|
|
341 }
|
|
|
342
|
|
|
343
|
|
|
344 /**********************************************************************/
|
|
593
|
345 /* Enabling/disabling signals */
|
|
|
346 /**********************************************************************/
|
|
|
347
|
|
|
348 static int interrupts_initted;
|
|
|
349
|
|
|
350 void
|
|
|
351 stop_interrupts (void)
|
|
|
352 {
|
|
|
353 if (!interrupts_initted)
|
|
|
354 return;
|
|
|
355 #if defined(SIGIO) && !defined(BROKEN_SIGIO)
|
|
|
356 unrequest_sigio ();
|
|
|
357 #endif
|
|
|
358 stop_async_timeouts ();
|
|
|
359 }
|
|
|
360
|
|
|
361 void
|
|
|
362 start_interrupts (void)
|
|
|
363 {
|
|
|
364 if (!interrupts_initted)
|
|
|
365 return;
|
|
|
366 #if defined(SIGIO) && !defined(BROKEN_SIGIO)
|
|
|
367 request_sigio ();
|
|
|
368 #endif
|
|
|
369 start_async_timeouts ();
|
|
|
370 }
|
|
|
371
|
|
|
372
|
|
|
373 static void
|
|
|
374 establish_slow_interrupt_timer (void)
|
|
|
375 {
|
|
|
376 EMACS_TIME thyme;
|
|
|
377
|
|
|
378 EMACS_SET_SECS_USECS (thyme, SLOWED_DOWN_INTERRUPTS_SECS, 0);
|
|
|
379 set_one_shot_timer (thyme);
|
|
|
380 }
|
|
|
381
|
|
|
382 /* Some functions don't like being interrupted with SIGALRM or SIGIO.
|
|
|
383 Previously we were calling stop_interrupts() / start_interrupts(),
|
|
|
384 but then if the program hangs in one of those functions, e.g.
|
|
|
385 waiting for a connect(), we're really screwed. So instead we
|
|
|
386 just "slow them down". We do this by disabling all interrupts
|
|
|
387 and then installing a timer of length fairly large, like 5 or
|
|
|
388 10 secs. That way, any "legitimate" connections (which should
|
|
|
389 take a fairly short amount of time) go through OK, but we can
|
|
|
390 interrupt bogus ones. */
|
|
|
391
|
|
|
392 void
|
|
|
393 slow_down_interrupts (void)
|
|
|
394 {
|
|
|
395 /* We have to set the flag *before* setting the slowed-down timer,
|
|
|
396 to avoid a race condition -- if the signal occurs between the
|
|
|
397 call to set_one_shot_timer() and the setting of this flag,
|
|
|
398 async_timeout_happened will get set, which will be a Bad Thing if
|
|
|
399 there were no timeouts on the queue. */
|
|
|
400 interrupts_slowed_down++;
|
|
|
401 if (interrupts_slowed_down == 1)
|
|
|
402 {
|
|
|
403 stop_interrupts ();
|
|
|
404 establish_slow_interrupt_timer ();
|
|
|
405 }
|
|
|
406 }
|
|
|
407
|
|
|
408 void
|
|
|
409 speed_up_interrupts (void)
|
|
|
410 {
|
|
|
411 if (interrupts_slowed_down > 0)
|
|
|
412 {
|
|
|
413 start_interrupts ();
|
|
|
414 /* Change this flag AFTER fiddling with interrupts, for the same
|
|
|
415 race-condition reasons as above. */
|
|
|
416 interrupts_slowed_down--;
|
|
|
417 }
|
|
|
418 }
|
|
|
419
|
|
|
420
|
|
|
421 /**********************************************************************/
|
|
|
422 /* The mechanism that drives it all */
|
|
428
|
423 /**********************************************************************/
|
|
|
424
|
|
593
|
425 /* called from QUIT when something_happened gets set (as a result of
|
|
|
426 a signal) */
|
|
|
427
|
|
853
|
428 void
|
|
593
|
429 check_what_happened (void)
|
|
|
430 {
|
|
771
|
431 /* No GC can happen anywhere here. handle_async_timeout_signal()
|
|
|
432 prevents GC (from asynch timeout handler), so does check_quit()
|
|
|
433 (from processing a message such as WM_INITMENU as a result of
|
|
|
434 draining the message queue). establish_slow_interrupt_timer() is
|
|
|
435 too low-level to do anything that might invoke QUIT or call Lisp
|
|
|
436 code. */
|
|
1318
|
437
|
|
|
438 #ifdef ERROR_CHECK_TRAPPING_PROBLEMS
|
|
|
439 /* When in a critical section, don't reset something_happened, so that
|
|
|
440 every single QUIT will verify proper wrapping. (something_happened
|
|
|
441 was set by enter_redisplay_critical_section() and will be reset
|
|
|
442 upon exit.) */
|
|
|
443 if (!in_display)
|
|
|
444 #endif
|
|
|
445 something_happened = 0;
|
|
|
446
|
|
593
|
447 if (async_timeout_happened)
|
|
|
448 {
|
|
|
449 async_timeout_happened = 0;
|
|
|
450 handle_async_timeout_signal ();
|
|
|
451 }
|
|
|
452 if (slowed_interrupt_timeout_happened)
|
|
|
453 {
|
|
|
454 slowed_interrupt_timeout_happened = 0;
|
|
|
455 establish_slow_interrupt_timer ();
|
|
|
456 }
|
|
|
457
|
|
853
|
458 check_quit ();
|
|
593
|
459 }
|
|
|
460
|
|
|
461 #ifdef SIGIO
|
|
|
462
|
|
|
463 /* Signal handler for SIGIO. */
|
|
|
464
|
|
|
465 static void
|
|
2286
|
466 input_available_signal (int SIG_ARG_MAYBE_UNUSED (signo))
|
|
593
|
467 {
|
|
|
468 something_happened = 1; /* tell QUIT to wake up */
|
|
|
469 quit_check_signal_happened = 1;
|
|
|
470 quit_check_signal_tick_count++;
|
|
|
471 EMACS_REESTABLISH_SIGNAL (signo, input_available_signal);
|
|
|
472 SIGRETURN;
|
|
|
473 }
|
|
|
474
|
|
|
475 #endif /* SIGIO */
|
|
|
476
|
|
|
477 /* Actual signal handler for SIGALRM. Called when:
|
|
|
478
|
|
|
479 -- asynchronous timeouts (added with `add-async-timeout') go off
|
|
|
480
|
|
|
481 -- when the poll-for-quit timer (used for C-g handling; more or
|
|
|
482 less when SIGIO is unavailable or BROKEN_SIGIO is defined) or
|
|
|
483 poll-for-sigchld timer (used when BROKEN_SIGCHLD is defined) go
|
|
|
484 off. The latter two timers, if set, normally go off every 1/4
|
|
|
485 of a second -- see NORMAL_QUIT_CHECK_TIMEOUT_MSECS and
|
|
|
486 NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS. (Both of these timers are
|
|
|
487 treated like other asynchronous timeouts, but special-cased
|
|
|
488 in handle_async_timeout_signal().)
|
|
|
489
|
|
|
490 -- we called slow_down_interrupts() and SLOWED_DOWN_INTERRUPTS_SECS
|
|
|
491 (or a multiple of it) has elapsed.
|
|
|
492
|
|
|
493 Note that under Windows, we have no working setitimer(), so we
|
|
|
494 simulate it using the multimedia timeout functions,
|
|
|
495 e.g. timeSetEvent(). See setitimer() in nt.c.
|
|
|
496
|
|
|
497 Note also that we don't actually *do* anything here (except in the
|
|
|
498 case of can_break_system_calls). Instead, we just set various
|
|
|
499 flags; next time QUIT is called, the flags will cause
|
|
|
500 check_what_happened() to be called, at which point we do everything
|
|
|
501 indicated by the flags.
|
|
|
502 */
|
|
|
503
|
|
|
504 static SIGTYPE
|
|
|
505 alarm_signal (int signo)
|
|
|
506 {
|
|
|
507 something_happened = 1; /* tell QUIT to wake up and call
|
|
|
508 check_what_happened() */
|
|
|
509
|
|
|
510 if (interrupts_slowed_down)
|
|
|
511 {
|
|
|
512 /* we are in "slowed-down interrupts" mode; the only alarm
|
|
|
513 happening here is the slowed-down quit-check alarm, so
|
|
|
514 we set this flag.
|
|
|
515
|
|
|
516 Do NOT set async_timeout_happened, because we don't want
|
|
|
517 anyone looking at the timeout queue -- async timeouts
|
|
|
518 are disabled. */
|
|
|
519 quit_check_signal_happened = 1;
|
|
|
520 quit_check_signal_tick_count++;
|
|
|
521 /* make sure we establish the slow timer again. */
|
|
|
522 slowed_interrupt_timeout_happened = 1;
|
|
|
523
|
|
|
524 /* can_break_system_calls is set when we want to break out of
|
|
|
525 non-interruptible system calls. */
|
|
|
526 if (can_break_system_calls)
|
|
|
527 {
|
|
|
528 /* reset the flag for safety and such. Do this *before*
|
|
|
529 unblocking or reestablishing the signal to avoid potential
|
|
|
530 race conditions. */
|
|
|
531 can_break_system_calls = 0;
|
|
|
532 #ifndef WIN32_NATIVE
|
|
|
533 /* #### I didn't add this WIN32_NATIVE check. I'm not sure
|
|
|
534 why it's here. But then again, someone needs to review
|
|
|
535 this can_break_system_calls stuff and see if it still
|
|
|
536 makes sense. --ben */
|
|
|
537 EMACS_UNBLOCK_SIGNAL (signo);
|
|
|
538 EMACS_REESTABLISH_SIGNAL (signo, alarm_signal);
|
|
|
539 LONGJMP (break_system_call_jump, 0);
|
|
|
540 #endif
|
|
|
541 }
|
|
|
542 }
|
|
|
543 else
|
|
|
544 {
|
|
|
545 async_timeout_happened = 1;
|
|
|
546 if (emacs_is_blocking)
|
|
|
547 async_timeout_happened_while_emacs_was_blocking = 1;
|
|
|
548 /* #### This is for QUITP. When it is run, it may not be the
|
|
|
549 place to do arbitrary stuff like run asynch. handlers, but
|
|
|
550 it needs to know whether the poll-for-quit asynch. timeout
|
|
|
551 went off. Rather than put the code in to compute this
|
|
|
552 specially, we just set this flag. Should fix this. */
|
|
|
553 quit_check_signal_happened = 1;
|
|
|
554
|
|
|
555 #ifdef HAVE_UNIXOID_EVENT_LOOP
|
|
|
556 signal_fake_event ();
|
|
|
557 #endif
|
|
|
558 }
|
|
|
559
|
|
|
560 EMACS_REESTABLISH_SIGNAL (signo, alarm_signal);
|
|
|
561 SIGRETURN;
|
|
|
562 }
|
|
|
563
|
|
428
|
564 /* Set this for debugging, to have a way to get out */
|
|
|
565 int stop_character; /* #### not currently implemented */
|
|
|
566
|
|
593
|
567 /* Signal handler for SIGINT and SIGQUIT. On TTY's, one of these two
|
|
|
568 signals will get generated in response to C-g. (When running under
|
|
|
569 X, C-g is handled using the SIGIO handler, which sets a flag
|
|
|
570 telling the QUIT macro to scan the unread events for a ^G.)
|
|
|
571 */
|
|
428
|
572
|
|
|
573 static SIGTYPE
|
|
|
574 interrupt_signal (int sig)
|
|
|
575 {
|
|
|
576 /* This function can call lisp */
|
|
|
577 /* #### we should NOT be calling lisp from a signal handler, boys
|
|
|
578 and girls */
|
|
|
579 /* Must preserve main program's value of errno. */
|
|
|
580 int old_errno = errno;
|
|
|
581
|
|
|
582 EMACS_REESTABLISH_SIGNAL (sig, interrupt_signal);
|
|
|
583
|
|
|
584 if (sigint_happened && CONSOLEP (Vcontrolling_terminal) &&
|
|
|
585 CONSOLE_LIVE_P (XCONSOLE (Vcontrolling_terminal)) &&
|
|
|
586 !emacs_is_blocking)
|
|
|
587 {
|
|
593
|
588 /* #### this is inherited from GNU Emacs. Do we really want this?
|
|
|
589 --ben */
|
|
428
|
590 char c;
|
|
|
591 fflush (stdout);
|
|
|
592 reset_initial_console ();
|
|
|
593 EMACS_UNBLOCK_SIGNAL (sig);
|
|
|
594 #ifdef SIGTSTP /* Support possible in later USG versions */
|
|
|
595 /*
|
|
|
596 * On systems which can suspend the current process and return to the original
|
|
|
597 * shell, this command causes the user to end up back at the shell.
|
|
|
598 * The "Auto-save" and "Abort" questions are not asked until
|
|
|
599 * the user elects to return to emacs, at which point he can save the current
|
|
|
600 * job and either dump core or continue.
|
|
|
601 */
|
|
|
602 sys_suspend ();
|
|
|
603 #else
|
|
|
604 /* Perhaps should really fork an inferior shell?
|
|
|
605 But that would not provide any way to get back
|
|
|
606 to the original shell, ever. */
|
|
|
607 stdout_out ("No support for stopping a process on this operating system;\n");
|
|
|
608 stdout_out ("you can continue or abort.\n");
|
|
|
609 #endif /* not SIGTSTP */
|
|
|
610 stdout_out ("Auto-save? (y or n) ");
|
|
|
611 if (((c = getc (stdin)) & ~040) == 'Y')
|
|
|
612 Fdo_auto_save (Qnil, Qnil);
|
|
|
613 while (c != '\n')
|
|
|
614 c = getc (stdin);
|
|
|
615 stdout_out ("Abort (and dump core)? (y or n) ");
|
|
|
616 if (((c = getc (stdin)) & ~040) == 'Y')
|
|
2500
|
617 ABORT ();
|
|
428
|
618 while (c != '\n')
|
|
|
619 c = getc (stdin);
|
|
|
620 stdout_out ("Continuing...\n");
|
|
|
621 reinit_initial_console ();
|
|
|
622 MARK_FRAME_CHANGED (XFRAME (DEVICE_SELECTED_FRAME
|
|
|
623 (XDEVICE (CONSOLE_SELECTED_DEVICE
|
|
|
624 (XCONSOLE
|
|
|
625 (Vcontrolling_terminal))))));
|
|
|
626 }
|
|
|
627 else
|
|
|
628 {
|
|
|
629 /* Else request quit when it's safe */
|
|
|
630 Vquit_flag = Qt;
|
|
|
631 sigint_happened = 1;
|
|
|
632 #ifdef HAVE_UNIXOID_EVENT_LOOP
|
|
|
633 signal_fake_event ();
|
|
|
634 #endif
|
|
|
635 }
|
|
|
636 errno = old_errno;
|
|
|
637 SIGRETURN;
|
|
|
638 }
|
|
|
639
|
|
593
|
640
|
|
|
641 /**********************************************************************/
|
|
|
642 /* Control-G checking */
|
|
|
643 /**********************************************************************/
|
|
|
644
|
|
2367
|
645 /*
|
|
853
|
646
|
|
2367
|
647 Info on Control-G checking:
|
|
853
|
648
|
|
2367
|
649 (Info-goto-node "(internals)Control-G (Quit) Checking")
|
|
|
650 */
|
|
853
|
651
|
|
771
|
652 /* Defer all checking or processing of C-g. You can do this, for example,
|
|
|
653 if you want to read C-g's as events. (In that case, you should set
|
|
|
654 Vquit_flag to Qnil just before you unbind, because it typically gets set
|
|
|
655 as a result of reading C-g.) */
|
|
|
656
|
|
|
657 int
|
|
428
|
658 begin_dont_check_for_quit (void)
|
|
|
659 {
|
|
771
|
660 int depth = specpdl_depth ();
|
|
|
661 /* As an optimization in QUIT_FLAG_SAYS_SHOULD_QUIT, we bind inhibit-quit
|
|
|
662 to t -- it has to be checked anyway, and by doing this, we only need
|
|
|
663 to check dont_check_for_quit when quit-flag == `critical', which is
|
|
|
664 rare. */
|
|
428
|
665 specbind (Qinhibit_quit, Qt);
|
|
853
|
666 internal_bind_int (&dont_check_for_quit, 1);
|
|
771
|
667
|
|
|
668 return depth;
|
|
428
|
669 }
|
|
|
670
|
|
853
|
671 /* If we're inside of a begin_dont_check_for_quit() section, but want
|
|
|
672 to temporarily enable quit-checking, call this. This is used in
|
|
|
673 particular when processing menu filters -- some menu filters do
|
|
|
674 antisocial things like load large amounts of Lisp code (custom in
|
|
|
675 particular), and we obviously want a way of breaking out of any
|
|
|
676 problems. If you do use this, you should really be trapping the
|
|
|
677 throw() that comes from the quitting (as does the code that handles
|
|
|
678 menus popping up). */
|
|
|
679
|
|
428
|
680 int
|
|
853
|
681 begin_do_check_for_quit (void)
|
|
|
682 {
|
|
|
683 int depth = specpdl_depth ();
|
|
|
684 specbind (Qinhibit_quit, Qnil);
|
|
|
685 internal_bind_int (&dont_check_for_quit, 0);
|
|
|
686 /* #### should we set Vquit_flag to Qnil? */
|
|
|
687 return depth;
|
|
|
688 }
|
|
|
689
|
|
|
690 /* The effect of this function is to set Vquit_flag appropriately if the
|
|
|
691 user pressed C-g or Sh-C-g. After this function finishes, Vquit_flag
|
|
|
692 will be Qt for C-g, Qcritical for Sh-C-g, and unchanged otherwise.
|
|
|
693 The C-g or Sh-C-g is discarded, so it won't be noticed again.
|
|
|
694 */
|
|
|
695
|
|
2518
|
696
|
|
|
697
|
|
853
|
698 void
|
|
428
|
699 check_quit (void)
|
|
|
700 {
|
|
853
|
701 int specdepth;
|
|
|
702
|
|
428
|
703 if (dont_check_for_quit)
|
|
853
|
704 return;
|
|
428
|
705
|
|
|
706 if (quit_check_signal_happened)
|
|
|
707 {
|
|
2034
|
708 #ifdef ERROR_CHECK_TRAPPING_PROBLEMS
|
|
|
709 /* Since the code below can call Lisp, make sure that proper wrapping is
|
|
|
710 in place during redisplay. */
|
|
2518
|
711 #if 0
|
|
2034
|
712 assert_with_message
|
|
|
713 (proper_redisplay_wrapping_in_place (),
|
|
|
714 "QUIT called from within redisplay without being properly wrapped");
|
|
2518
|
715 #else
|
|
|
716 /* FUCKME! It looks like we cannot even check for QUIT, *EVER*, during
|
|
|
717 redisplay. Checking for quit can dispatch events, which can enter
|
|
|
718 redisplay recursively, which can trip on
|
|
|
719
|
|
|
720 Fatal error: assertion failed, file c:\xemacs\build\src\redisplay.c, line 5532,
|
|
|
721 !dy->locked
|
|
|
722
|
|
|
723 Backtrace given in
|
|
|
724
|
|
|
725 (Info-goto-node "(internals)Nasty Bugs due to Reentrancy in Redisplay Structures handling QUIT")
|
|
|
726
|
|
|
727 */
|
|
|
728 assert_with_message
|
|
|
729 (!in_display,
|
|
|
730 "QUIT called from within redisplay without being properly wrapped");
|
|
|
731 #endif /* 0 */
|
|
|
732 #endif /* ERROR_CHECK_TRAPPING_PROBLEMS */
|
|
2034
|
733
|
|
1123
|
734 /* Since arbitrary Lisp code may be executed (e.g. through a menu
|
|
|
735 filter, see backtrace directly above), GC might happen,
|
|
771
|
736 which would majorly fuck a lot of things, e.g. re_match()
|
|
|
737 [string gets relocated] and lots of other code that's not
|
|
|
738 prepared to handle GC in QUIT. */
|
|
853
|
739 specdepth = begin_gc_forbidden ();
|
|
428
|
740 quit_check_signal_happened = 0;
|
|
|
741 event_stream_quit_p ();
|
|
771
|
742 unbind_to (specdepth);
|
|
428
|
743 }
|
|
|
744 }
|
|
|
745
|
|
|
746
|
|
|
747
|
|
|
748 void
|
|
|
749 init_poll_for_quit (void)
|
|
|
750 {
|
|
|
751 #if !defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)
|
|
|
752 /* Check for C-g every 1/4 of a second.
|
|
|
753
|
|
|
754 #### This is just a guess. Some investigation will have to be
|
|
|
755 done to see what the best value is. The best value is the
|
|
|
756 smallest possible value that doesn't cause a significant amount
|
|
|
757 of running time to be spent in C-g checking. */
|
|
|
758 if (!poll_for_quit_id)
|
|
|
759 poll_for_quit_id =
|
|
|
760 event_stream_generate_wakeup (NORMAL_QUIT_CHECK_TIMEOUT_MSECS,
|
|
|
761 NORMAL_QUIT_CHECK_TIMEOUT_MSECS,
|
|
|
762 Qnil, Qnil, 1);
|
|
|
763 #endif /* not SIGIO and not DONT_POLL_FOR_QUIT */
|
|
|
764 }
|
|
|
765
|
|
593
|
766 #if 0 /* not used anywhere */
|
|
|
767
|
|
428
|
768 void
|
|
|
769 reset_poll_for_quit (void)
|
|
|
770 {
|
|
|
771 #if !defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)
|
|
|
772 if (poll_for_quit_id)
|
|
|
773 {
|
|
|
774 event_stream_disable_wakeup (poll_for_quit_id, 1);
|
|
|
775 poll_for_quit_id = 0;
|
|
|
776 }
|
|
|
777 #endif /* not SIGIO and not DONT_POLL_FOR_QUIT */
|
|
|
778 }
|
|
|
779
|
|
593
|
780 #endif /* 0 */
|
|
|
781
|
|
853
|
782 #if defined (HAVE_UNIX_PROCESSES) && !defined (SIGCHLD)
|
|
428
|
783
|
|
|
784 static void
|
|
|
785 init_poll_for_sigchld (void)
|
|
|
786 {
|
|
|
787 /* Check for terminated processes every 1/4 of a second.
|
|
|
788
|
|
|
789 #### This is just a guess. Some investigation will have to be
|
|
|
790 done to see what the best value is. The best value is the
|
|
|
791 smallest possible value that doesn't cause a significant amount
|
|
|
792 of running time to be spent in process-termination checking.
|
|
|
793 */
|
|
|
794 poll_for_sigchld_id =
|
|
|
795 event_stream_generate_wakeup (NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS,
|
|
|
796 NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS,
|
|
|
797 Qnil, Qnil, 1);
|
|
|
798 }
|
|
|
799
|
|
|
800 #endif /* not SIGCHLD */
|
|
|
801
|
|
|
802
|
|
|
803 /************************************************************************/
|
|
|
804 /* initialization */
|
|
|
805 /************************************************************************/
|
|
|
806
|
|
|
807 /* If we've been nohup'ed, keep it that way.
|
|
|
808 This allows `nohup xemacs &' to work.
|
|
|
809 More generally, if a normally fatal signal has been redirected
|
|
|
810 to SIG_IGN by our invocation environment, trust the environment.
|
|
|
811 This keeps xemacs from being killed by a SIGQUIT intended for a
|
|
|
812 different process after having been backgrounded under a
|
|
|
813 non-job-control shell! */
|
|
|
814 static void
|
|
|
815 handle_signal_if_fatal (int signo)
|
|
|
816 {
|
|
613
|
817 if (EMACS_SIGNAL (signo, fatal_error_signal) == SIG_IGN)
|
|
|
818 EMACS_SIGNAL (signo, SIG_IGN);
|
|
428
|
819 }
|
|
|
820
|
|
|
821 void
|
|
|
822 init_signals_very_early (void)
|
|
|
823 {
|
|
|
824 /* Catch all signals that would kill us.
|
|
|
825 Don't catch these signals in batch mode if not initialized.
|
|
|
826 On some machines, this sets static data that would make
|
|
|
827 signal fail to work right when the dumped Emacs is run. */
|
|
|
828 if (noninteractive && !initialized)
|
|
|
829 return;
|
|
|
830
|
|
|
831 handle_signal_if_fatal (SIGILL); /* ANSI */
|
|
|
832 handle_signal_if_fatal (SIGABRT); /* ANSI */
|
|
|
833 handle_signal_if_fatal (SIGFPE); /* ANSI */
|
|
|
834 handle_signal_if_fatal (SIGSEGV); /* ANSI */
|
|
|
835 handle_signal_if_fatal (SIGTERM); /* ANSI */
|
|
|
836
|
|
|
837
|
|
|
838 #ifdef SIGHUP
|
|
|
839 handle_signal_if_fatal (SIGHUP); /* POSIX */
|
|
|
840 #endif
|
|
|
841 #ifdef SIGQUIT
|
|
|
842 handle_signal_if_fatal (SIGQUIT); /* POSIX */
|
|
|
843 #endif
|
|
|
844 #ifdef SIGTRAP
|
|
|
845 handle_signal_if_fatal (SIGTRAP); /* POSIX */
|
|
|
846 #endif
|
|
|
847 #ifdef SIGUSR1
|
|
|
848 handle_signal_if_fatal (SIGUSR1); /* POSIX */
|
|
|
849 #endif
|
|
|
850 #ifdef SIGUSR2
|
|
|
851 handle_signal_if_fatal (SIGUSR2); /* POSIX */
|
|
|
852 #endif
|
|
|
853 #ifdef SIGPIPE
|
|
|
854 handle_signal_if_fatal (SIGPIPE); /* POSIX */
|
|
|
855 #endif
|
|
|
856 #ifdef SIGALRM
|
|
|
857 /* This will get reset later, once we're
|
|
|
858 capable of handling it properly. */
|
|
|
859 handle_signal_if_fatal (SIGALRM); /* POSIX */
|
|
|
860 #endif
|
|
|
861
|
|
|
862
|
|
|
863 #ifdef SIGBUS
|
|
|
864 handle_signal_if_fatal (SIGBUS); /* XPG5 */
|
|
|
865 #endif
|
|
|
866 #ifdef SIGSYS
|
|
|
867 handle_signal_if_fatal (SIGSYS); /* XPG5 */
|
|
|
868 #endif
|
|
|
869 #ifdef SIGXCPU
|
|
|
870 handle_signal_if_fatal (SIGXCPU); /* XPG5 */
|
|
|
871 #endif
|
|
|
872 #ifdef SIGXFSZ
|
|
|
873 handle_signal_if_fatal (SIGXFSZ); /* XPG5 */
|
|
|
874 #endif
|
|
|
875 #ifdef SIGVTALRM
|
|
|
876 handle_signal_if_fatal (SIGVTALRM); /* XPG5 */
|
|
|
877 #endif
|
|
|
878 #ifdef SIGPROF
|
|
|
879 /* Messes up the REAL profiler */
|
|
|
880 /* handle_signal_if_fatal (SIGPROF); */ /* XPG5 */
|
|
|
881 #endif
|
|
|
882
|
|
|
883
|
|
|
884 #ifdef SIGHWE
|
|
|
885 handle_signal_if_fatal (SIGHWE);
|
|
|
886 #endif
|
|
|
887 #ifdef SIGPRE
|
|
|
888 handle_signal_if_fatal (SIGPRE);
|
|
|
889 #endif
|
|
|
890 #ifdef SIGORE
|
|
|
891 handle_signal_if_fatal (SIGORE);
|
|
|
892 #endif
|
|
|
893 #ifdef SIGUME
|
|
|
894 handle_signal_if_fatal (SIGUME);
|
|
|
895 #endif
|
|
|
896 #ifdef SIGDLK
|
|
|
897 handle_signal_if_fatal (SIGDLK);
|
|
|
898 #endif
|
|
|
899 #ifdef SIGCPULIM
|
|
|
900 handle_signal_if_fatal (SIGCPULIM);
|
|
|
901 #endif
|
|
|
902 #ifdef SIGIOT
|
|
|
903 handle_signal_if_fatal (SIGIOT);
|
|
|
904 #endif
|
|
|
905 #ifdef SIGEMT
|
|
|
906 handle_signal_if_fatal (SIGEMT);
|
|
|
907 #endif
|
|
|
908 #ifdef SIGLOST
|
|
|
909 handle_signal_if_fatal (SIGLOST);
|
|
|
910 #endif
|
|
|
911 #ifdef SIGSTKFLT /* coprocessor stack fault under Linux */
|
|
|
912 handle_signal_if_fatal (SIGSTKFLT);
|
|
|
913 #endif
|
|
|
914 #ifdef SIGUNUSED /* exists under Linux, and will kill process! */
|
|
|
915 handle_signal_if_fatal (SIGUNUSED);
|
|
|
916 #endif
|
|
|
917
|
|
|
918 #ifdef AIX
|
|
|
919 /* 20 is SIGCHLD, 21 is SIGTTIN, 22 is SIGTTOU. */
|
|
|
920 #ifndef _I386
|
|
|
921 handle_signal_if_fatal (SIGIOINT);
|
|
|
922 #endif
|
|
|
923 handle_signal_if_fatal (SIGGRANT);
|
|
|
924 handle_signal_if_fatal (SIGRETRACT);
|
|
|
925 handle_signal_if_fatal (SIGSOUND);
|
|
|
926 handle_signal_if_fatal (SIGMSG);
|
|
|
927 #endif /* AIX */
|
|
|
928
|
|
|
929 #ifdef SIGDANGER
|
|
|
930 /* This just means available memory is getting low. */
|
|
613
|
931 EMACS_SIGNAL (SIGDANGER, memory_warning_signal);
|
|
428
|
932 #endif
|
|
|
933 }
|
|
|
934
|
|
|
935 void
|
|
|
936 syms_of_signal (void)
|
|
|
937 {
|
|
|
938 DEFSUBR (Fwaiting_for_user_input_p);
|
|
|
939 }
|
|
|
940
|
|
|
941 void
|
|
|
942 init_interrupts_late (void)
|
|
|
943 {
|
|
|
944 if (!noninteractive)
|
|
|
945 {
|
|
613
|
946 EMACS_SIGNAL (SIGINT, interrupt_signal);
|
|
428
|
947 #ifdef HAVE_TERMIO
|
|
|
948 /* On systems with TERMIO, C-g is set up for both SIGINT and SIGQUIT
|
|
|
949 and we can't tell which one it will give us. */
|
|
613
|
950 EMACS_SIGNAL (SIGQUIT, interrupt_signal);
|
|
428
|
951 #endif /* HAVE_TERMIO */
|
|
|
952 init_async_timeouts ();
|
|
|
953 #ifdef SIGIO
|
|
613
|
954 EMACS_SIGNAL (SIGIO, input_available_signal);
|
|
428
|
955 # ifdef SIGPOLL /* XPG5 */
|
|
|
956 /* Some systems (e.g. Motorola SVR4) losingly have different
|
|
|
957 values for SIGIO and SIGPOLL, and send SIGPOLL instead of
|
|
|
958 SIGIO. On those same systems, an uncaught SIGPOLL kills the
|
|
|
959 process. */
|
|
613
|
960 EMACS_SIGNAL (SIGPOLL, input_available_signal);
|
|
428
|
961 # endif
|
|
|
962 #elif !defined (DONT_POLL_FOR_QUIT)
|
|
|
963 init_poll_for_quit ();
|
|
|
964 #endif
|
|
|
965 }
|
|
|
966
|
|
853
|
967 #if defined (HAVE_UNIX_PROCESSES) && !defined (SIGCHLD)
|
|
428
|
968 init_poll_for_sigchld ();
|
|
|
969 #endif
|
|
|
970
|
|
|
971 EMACS_UNBLOCK_ALL_SIGNALS ();
|
|
|
972
|
|
|
973 interrupts_initted = 1;
|
|
|
974 }
|
|
|
975
|
