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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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593
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3 Copyright (C) 1995, 1996, 2001 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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28 #include "events.h" /* for signal_fake_event() */
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29 #include "frame.h"
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593
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30 #include "process.h"
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428
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31 #include "sysdep.h"
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32 #include "syssignal.h"
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33 #include "systime.h"
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34
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442
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35 #include "sysfile.h"
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428
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36
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37 /* Set to 1 when a quit-check signal (either a SIGIO interrupt or
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38 the asynch. timeout for poll-for-quit) occurs. The QUITP
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39 macro may look at this. */
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40 volatile int quit_check_signal_happened;
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41
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42 /* Count of the number of times a quit-check signal has occurred.
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43 Some stuff in event-Xt.c looks at this. */
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44 volatile int quit_check_signal_tick_count;
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45
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46 /* Set to 1 when a SIGINT (or SIGQUIT) interrupt is processed.
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47 maybe_read_quit_event() looks at this. */
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48 volatile int sigint_happened;
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49
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50 /* Set to 1 when an asynch. timeout signal occurs. */
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593
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51 static volatile int async_timeout_happened;
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52
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53 /* Set to 1 when a multiple of SLOWED_DOWN_INTERRUPTS_SECS elapses,
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54 after slow_down_interrupts() is called. */
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55 static volatile int slowed_interrupt_timeout_happened;
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428
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56
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57 /* This is used to synchronize setting the waiting_for_user_input_p
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58 flag. */
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593
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59 static volatile int async_timeout_happened_while_emacs_was_blocking;
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428
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60
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61 /* See check_quit() for when this is set. */
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62 int dont_check_for_quit;
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63
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593
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64 static int poll_for_quit_id;
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65 static int poll_for_sigchld_id;
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428
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66
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67 /* This variable is used to communicate to a lisp
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68 process-filter/sentinel/asynchronous callback (via the function
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69 Fwaiting_for_user_input_p below) whether XEmacs was waiting for
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70 user-input when that process-filter was called. */
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71 static int waiting_for_user_input_p;
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72
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73 static int interrupts_slowed_down;
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74
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75 #define SLOWED_DOWN_INTERRUPTS_SECS 15
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76 #define NORMAL_QUIT_CHECK_TIMEOUT_MSECS 250
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77 #define NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS 250
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78
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79 /* Used so that signals can break out of system calls that aren't
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80 naturally interruptible. */
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81
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82 JMP_BUF break_system_call_jump;
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83 volatile int can_break_system_calls;
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84
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593
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85 static SIGTYPE alarm_signal (int signo);
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86
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87
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428
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88
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89 /**********************************************************************/
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90 /* Asynchronous timeout functions */
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91 /**********************************************************************/
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92
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593
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93 /* See the comment in event-stream.c, under major heading "Timeouts",
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94 for the difference between low-level (one-shot) and high-level
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95 (periodic/resignaling) timeouts. */
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96
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428
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97 /* The pending timers are stored in an ordered list, where the first timer
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98 on the list is the first one to fire. Times recorded here are
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99 absolute. */
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100 static struct low_level_timeout *async_timer_queue;
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101
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102 /* Nonzero means async timers are temporarily suppressed. */
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103 static int async_timer_suppress_count;
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104
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105 static void
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106 set_one_shot_timer (EMACS_TIME interval)
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107 {
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108 #ifdef HAVE_SETITIMER
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109 struct itimerval it;
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110 it.it_value = interval;
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111 EMACS_SET_SECS_USECS (it.it_interval, 0, 0);
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112 setitimer (ITIMER_REAL, &it, 0);
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113 #else
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114 int secs;
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115 EMACS_TIME_TO_INT (interval, secs);
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116 alarm (secs);
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117 #endif
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118 }
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119
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120 static void
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121 reset_interval_timer (void)
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122 {
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123 EMACS_TIME interval;
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124
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125 /* Get the interval to set. If an interval is available,
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126 make sure it's not zero (this is a valid return, but it will
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127 cause the timer to get disabled, so convert it to a very short
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128 time). */
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129 if (get_low_level_timeout_interval (async_timer_queue, &interval))
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130 {
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131 if (EMACS_SECS (interval) == 0 && EMACS_USECS (interval) == 0)
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132 EMACS_SET_USECS (interval, 1);
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133 }
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134 else
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135 /* A time of 0 means "disable". */
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136 EMACS_SET_SECS_USECS (interval, 0, 0);
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137
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138 set_one_shot_timer (interval);
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139 }
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140
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141
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142 static void
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143 init_async_timeouts (void)
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144 {
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145 signal (SIGALRM, alarm_signal);
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146 async_timer_suppress_count = 0;
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147 }
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148
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149 /* Turn off async timeouts. */
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150
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151 static void
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152 stop_async_timeouts (void)
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153 {
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154 if (async_timer_suppress_count == 0)
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155 {
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156 /* If timer was on, turn it off. */
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157 EMACS_TIME thyme;
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158 EMACS_SET_SECS_USECS (thyme, 0, 0);
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159 set_one_shot_timer (thyme);
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160 }
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161 async_timer_suppress_count++;
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162 }
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163
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164 /* Turn on async timeouts again. */
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165
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166 static void
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167 start_async_timeouts (void)
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168 {
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169 assert (async_timer_suppress_count > 0);
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170 async_timer_suppress_count--;
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171 if (async_timer_suppress_count == 0)
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172 {
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173 /* Some callers turn off async timeouts and then use the alarm
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174 for their own purposes; so reinitialize everything. */
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175 signal (SIGALRM, alarm_signal);
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176 reset_interval_timer ();
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177 }
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178 }
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179
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593
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180 static void
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181 handle_async_timeout_signal (void)
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428
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182 {
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593
|
183 int interval_id;
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184 int wakeup_id;
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185 Lisp_Object fun, arg;
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186
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187 /* No checks for Vinhibit_quit here or anywhere else in this file!!!
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188 Otherwise critical quit will not work right.
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189 The only check for Vinhibit_quit is in QUIT itself. */
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190 interval_id = pop_low_level_timeout (&async_timer_queue, 0);
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191
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192 reset_interval_timer ();
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193 if (async_timeout_happened_while_emacs_was_blocking)
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194 {
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195 async_timeout_happened_while_emacs_was_blocking = 0;
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196 waiting_for_user_input_p = 1;
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197 }
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198
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199 wakeup_id = event_stream_resignal_wakeup (interval_id, 1, &fun, &arg);
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428
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200
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593
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201 if (wakeup_id == poll_for_quit_id)
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202 {
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203 quit_check_signal_happened = 1;
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204 quit_check_signal_tick_count++;
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205 }
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206 else if (wakeup_id == poll_for_sigchld_id)
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428
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207 {
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593
|
208 kick_status_notify ();
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428
|
209 }
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593
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210 else
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211 /* call1 GC-protects its arguments */
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212 call1_trapping_errors ("Error in asynchronous timeout callback",
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213 fun, arg);
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214
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215 waiting_for_user_input_p = 0;
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216 }
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217
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218 /* The following two functions are the external interface onto
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219 creating/deleting asynchronous interval timeouts, and are
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220 called by event-stream.c. We call back to event-stream.c using
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221 event_stream_resignal_wakeup(), when an interval goes off. */
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222
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223 int
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224 signal_add_async_interval_timeout (EMACS_TIME thyme)
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225 {
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226 int id = add_low_level_timeout (&async_timer_queue, thyme);
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227
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228 /* If this timeout is at the head of the queue, then we need to
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229 set the timer right now for this timeout. Otherwise, things
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230 are fine as-is; after the timers ahead of us are signalled,
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231 the timer will be set for us. */
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232
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233 if (async_timer_queue->id == id)
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234 reset_interval_timer ();
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235
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236 return id;
|
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428
|
237 }
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238
|
|
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239 void
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593
|
240 signal_remove_async_interval_timeout (int id)
|
|
428
|
241 {
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|
593
|
242 int first = (async_timer_queue && async_timer_queue->id == id);
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243 remove_low_level_timeout (&async_timer_queue, id);
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244
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245 /* If we removed the timeout from the head of the queue, then
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246 we need to reset the interval timer right now. */
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247 if (first)
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|
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248 reset_interval_timer ();
|
|
428
|
249 }
|
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250
|
|
593
|
251 /* If alarm() gets called when polling isn't disabled, it will mess up
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252 the asynchronous timeouts, and then C-g checking won't work again.
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253 Some libraries call alarm() directly, so we override the standard
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254 library's alarm() and abort() if the caller of the library function
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255 didn't wrap in stop_interrupts()/start_interrupts().
|
|
428
|
256
|
|
593
|
257 NOTE: We could potentially avoid the need to wrap by adding a
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258 one-shot timeout to simulate the alarm(), smashing our signal
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259 handler back into place, and calling the library function when the
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260 alarm goes off. But do we want to? We're not going to gain the
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261 ability to C-g out of library functions this way (unless we forcibly
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262 longjmp() out of a signal handler, which is likely to lead to a
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|
|
263 crash). --ben */
|
|
428
|
264
|
|
|
265 #ifdef HAVE_SETITIMER
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|
|
266 unsigned int
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|
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267 alarm (unsigned int howlong)
|
|
|
268 {
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|
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269 struct itimerval old_it, new_it;
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270
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|
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271 assert (async_timer_suppress_count > 0);
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272
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273 new_it.it_value.tv_sec = howlong;
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274 new_it.it_value.tv_usec = 0;
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275 new_it.it_interval.tv_sec = 0;
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|
276 new_it.it_interval.tv_usec = 0;
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277 setitimer (ITIMER_REAL, &new_it, &old_it);
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|
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278
|
|
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279 /* Never return zero if there was a timer outstanding. */
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|
280 return old_it.it_value.tv_sec + (old_it.it_value.tv_usec > 0 ? 1 : 0);
|
|
|
281 }
|
|
|
282 #endif
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|
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283
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|
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284 DEFUN ("waiting-for-user-input-p", Fwaiting_for_user_input_p, 0, 0, 0, /*
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285 Return non-nil if XEmacs is waiting for input from the user.
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286 This is intended for use by asynchronous timeout callbacks and by
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287 asynchronous process output filters and sentinels (not yet implemented
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288 in XEmacs). It will always be nil if XEmacs is not inside of
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289 an asynchronous timeout or process callback.
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290 */
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291 ())
|
|
|
292 {
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|
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293 return waiting_for_user_input_p ? Qt : Qnil;
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|
|
294 }
|
|
|
295
|
|
|
296
|
|
|
297 /**********************************************************************/
|
|
593
|
298 /* Enabling/disabling signals */
|
|
|
299 /**********************************************************************/
|
|
|
300
|
|
|
301 static int interrupts_initted;
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302
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303 void
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304 stop_interrupts (void)
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|
|
305 {
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|
|
306 if (!interrupts_initted)
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|
307 return;
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|
|
308 #if defined(SIGIO) && !defined(BROKEN_SIGIO)
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|
|
309 unrequest_sigio ();
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|
|
310 #endif
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|
|
311 stop_async_timeouts ();
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|
|
312 }
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|
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313
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|
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314 void
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|
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315 start_interrupts (void)
|
|
|
316 {
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|
|
317 if (!interrupts_initted)
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|
|
318 return;
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|
|
319 #if defined(SIGIO) && !defined(BROKEN_SIGIO)
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|
|
320 request_sigio ();
|
|
|
321 #endif
|
|
|
322 start_async_timeouts ();
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|
|
323 }
|
|
|
324
|
|
|
325
|
|
|
326 static void
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|
|
327 establish_slow_interrupt_timer (void)
|
|
|
328 {
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|
|
329 EMACS_TIME thyme;
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|
|
330
|
|
|
331 EMACS_SET_SECS_USECS (thyme, SLOWED_DOWN_INTERRUPTS_SECS, 0);
|
|
|
332 set_one_shot_timer (thyme);
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|
|
333 }
|
|
|
334
|
|
|
335 /* Some functions don't like being interrupted with SIGALRM or SIGIO.
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|
|
336 Previously we were calling stop_interrupts() / start_interrupts(),
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|
|
337 but then if the program hangs in one of those functions, e.g.
|
|
|
338 waiting for a connect(), we're really screwed. So instead we
|
|
|
339 just "slow them down". We do this by disabling all interrupts
|
|
|
340 and then installing a timer of length fairly large, like 5 or
|
|
|
341 10 secs. That way, any "legitimate" connections (which should
|
|
|
342 take a fairly short amount of time) go through OK, but we can
|
|
|
343 interrupt bogus ones. */
|
|
|
344
|
|
|
345 void
|
|
|
346 slow_down_interrupts (void)
|
|
|
347 {
|
|
|
348 /* We have to set the flag *before* setting the slowed-down timer,
|
|
|
349 to avoid a race condition -- if the signal occurs between the
|
|
|
350 call to set_one_shot_timer() and the setting of this flag,
|
|
|
351 async_timeout_happened will get set, which will be a Bad Thing if
|
|
|
352 there were no timeouts on the queue. */
|
|
|
353 interrupts_slowed_down++;
|
|
|
354 if (interrupts_slowed_down == 1)
|
|
|
355 {
|
|
|
356 stop_interrupts ();
|
|
|
357 establish_slow_interrupt_timer ();
|
|
|
358 }
|
|
|
359 }
|
|
|
360
|
|
|
361 void
|
|
|
362 speed_up_interrupts (void)
|
|
|
363 {
|
|
|
364 if (interrupts_slowed_down > 0)
|
|
|
365 {
|
|
|
366 start_interrupts ();
|
|
|
367 /* Change this flag AFTER fiddling with interrupts, for the same
|
|
|
368 race-condition reasons as above. */
|
|
|
369 interrupts_slowed_down--;
|
|
|
370 }
|
|
|
371 }
|
|
|
372
|
|
|
373 /* Cheesy but workable implementation of sleep() that doesn't
|
|
|
374 interfere with our periodic timers. */
|
|
|
375
|
|
|
376 void
|
|
|
377 emacs_sleep (int secs)
|
|
|
378 {
|
|
|
379 stop_interrupts ();
|
|
|
380 sleep (secs);
|
|
|
381 start_interrupts ();
|
|
|
382 }
|
|
|
383
|
|
|
384
|
|
|
385 /**********************************************************************/
|
|
|
386 /* The mechanism that drives it all */
|
|
428
|
387 /**********************************************************************/
|
|
|
388
|
|
593
|
389 /* called from QUIT when something_happened gets set (as a result of
|
|
|
390 a signal) */
|
|
|
391
|
|
|
392 int
|
|
|
393 check_what_happened (void)
|
|
|
394 {
|
|
|
395 something_happened = 0;
|
|
|
396 if (async_timeout_happened)
|
|
|
397 {
|
|
|
398 async_timeout_happened = 0;
|
|
|
399 handle_async_timeout_signal ();
|
|
|
400 }
|
|
|
401 if (slowed_interrupt_timeout_happened)
|
|
|
402 {
|
|
|
403 slowed_interrupt_timeout_happened = 0;
|
|
|
404 establish_slow_interrupt_timer ();
|
|
|
405 }
|
|
|
406
|
|
|
407 return check_quit ();
|
|
|
408 }
|
|
|
409
|
|
|
410 #ifdef SIGIO
|
|
|
411
|
|
|
412 /* Signal handler for SIGIO. */
|
|
|
413
|
|
|
414 static void
|
|
|
415 input_available_signal (int signo)
|
|
|
416 {
|
|
|
417 something_happened = 1; /* tell QUIT to wake up */
|
|
|
418 quit_check_signal_happened = 1;
|
|
|
419 quit_check_signal_tick_count++;
|
|
|
420 EMACS_REESTABLISH_SIGNAL (signo, input_available_signal);
|
|
|
421 SIGRETURN;
|
|
|
422 }
|
|
|
423
|
|
|
424 #endif /* SIGIO */
|
|
|
425
|
|
|
426 /* Actual signal handler for SIGALRM. Called when:
|
|
|
427
|
|
|
428 -- asynchronous timeouts (added with `add-async-timeout') go off
|
|
|
429
|
|
|
430 -- when the poll-for-quit timer (used for C-g handling; more or
|
|
|
431 less when SIGIO is unavailable or BROKEN_SIGIO is defined) or
|
|
|
432 poll-for-sigchld timer (used when BROKEN_SIGCHLD is defined) go
|
|
|
433 off. The latter two timers, if set, normally go off every 1/4
|
|
|
434 of a second -- see NORMAL_QUIT_CHECK_TIMEOUT_MSECS and
|
|
|
435 NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS. (Both of these timers are
|
|
|
436 treated like other asynchronous timeouts, but special-cased
|
|
|
437 in handle_async_timeout_signal().)
|
|
|
438
|
|
|
439 -- we called slow_down_interrupts() and SLOWED_DOWN_INTERRUPTS_SECS
|
|
|
440 (or a multiple of it) has elapsed.
|
|
|
441
|
|
|
442 Note that under Windows, we have no working setitimer(), so we
|
|
|
443 simulate it using the multimedia timeout functions,
|
|
|
444 e.g. timeSetEvent(). See setitimer() in nt.c.
|
|
|
445
|
|
|
446 Note also that we don't actually *do* anything here (except in the
|
|
|
447 case of can_break_system_calls). Instead, we just set various
|
|
|
448 flags; next time QUIT is called, the flags will cause
|
|
|
449 check_what_happened() to be called, at which point we do everything
|
|
|
450 indicated by the flags.
|
|
|
451 */
|
|
|
452
|
|
|
453 static SIGTYPE
|
|
|
454 alarm_signal (int signo)
|
|
|
455 {
|
|
|
456 something_happened = 1; /* tell QUIT to wake up and call
|
|
|
457 check_what_happened() */
|
|
|
458
|
|
|
459 if (interrupts_slowed_down)
|
|
|
460 {
|
|
|
461 /* we are in "slowed-down interrupts" mode; the only alarm
|
|
|
462 happening here is the slowed-down quit-check alarm, so
|
|
|
463 we set this flag.
|
|
|
464
|
|
|
465 Do NOT set async_timeout_happened, because we don't want
|
|
|
466 anyone looking at the timeout queue -- async timeouts
|
|
|
467 are disabled. */
|
|
|
468 quit_check_signal_happened = 1;
|
|
|
469 quit_check_signal_tick_count++;
|
|
|
470 /* make sure we establish the slow timer again. */
|
|
|
471 slowed_interrupt_timeout_happened = 1;
|
|
|
472
|
|
|
473 /* can_break_system_calls is set when we want to break out of
|
|
|
474 non-interruptible system calls. */
|
|
|
475 if (can_break_system_calls)
|
|
|
476 {
|
|
|
477 /* reset the flag for safety and such. Do this *before*
|
|
|
478 unblocking or reestablishing the signal to avoid potential
|
|
|
479 race conditions. */
|
|
|
480 can_break_system_calls = 0;
|
|
|
481 #ifndef WIN32_NATIVE
|
|
|
482 /* #### I didn't add this WIN32_NATIVE check. I'm not sure
|
|
|
483 why it's here. But then again, someone needs to review
|
|
|
484 this can_break_system_calls stuff and see if it still
|
|
|
485 makes sense. --ben */
|
|
|
486 EMACS_UNBLOCK_SIGNAL (signo);
|
|
|
487 EMACS_REESTABLISH_SIGNAL (signo, alarm_signal);
|
|
|
488 LONGJMP (break_system_call_jump, 0);
|
|
|
489 #endif
|
|
|
490 }
|
|
|
491 }
|
|
|
492 else
|
|
|
493 {
|
|
|
494 async_timeout_happened = 1;
|
|
|
495 if (emacs_is_blocking)
|
|
|
496 async_timeout_happened_while_emacs_was_blocking = 1;
|
|
|
497 /* #### This is for QUITP. When it is run, it may not be the
|
|
|
498 place to do arbitrary stuff like run asynch. handlers, but
|
|
|
499 it needs to know whether the poll-for-quit asynch. timeout
|
|
|
500 went off. Rather than put the code in to compute this
|
|
|
501 specially, we just set this flag. Should fix this. */
|
|
|
502 quit_check_signal_happened = 1;
|
|
|
503
|
|
|
504 #ifdef HAVE_UNIXOID_EVENT_LOOP
|
|
|
505 signal_fake_event ();
|
|
|
506 #endif
|
|
|
507 }
|
|
|
508
|
|
|
509 EMACS_REESTABLISH_SIGNAL (signo, alarm_signal);
|
|
|
510 SIGRETURN;
|
|
|
511 }
|
|
|
512
|
|
428
|
513 /* Set this for debugging, to have a way to get out */
|
|
|
514 int stop_character; /* #### not currently implemented */
|
|
|
515
|
|
593
|
516 /* Signal handler for SIGINT and SIGQUIT. On TTY's, one of these two
|
|
|
517 signals will get generated in response to C-g. (When running under
|
|
|
518 X, C-g is handled using the SIGIO handler, which sets a flag
|
|
|
519 telling the QUIT macro to scan the unread events for a ^G.)
|
|
|
520 */
|
|
428
|
521
|
|
|
522 static SIGTYPE
|
|
|
523 interrupt_signal (int sig)
|
|
|
524 {
|
|
|
525 /* This function can call lisp */
|
|
|
526 /* #### we should NOT be calling lisp from a signal handler, boys
|
|
|
527 and girls */
|
|
|
528 /* Must preserve main program's value of errno. */
|
|
|
529 int old_errno = errno;
|
|
|
530
|
|
|
531 EMACS_REESTABLISH_SIGNAL (sig, interrupt_signal);
|
|
|
532
|
|
|
533 if (sigint_happened && CONSOLEP (Vcontrolling_terminal) &&
|
|
|
534 CONSOLE_LIVE_P (XCONSOLE (Vcontrolling_terminal)) &&
|
|
|
535 !emacs_is_blocking)
|
|
|
536 {
|
|
593
|
537 /* #### this is inherited from GNU Emacs. Do we really want this?
|
|
|
538 --ben */
|
|
428
|
539 char c;
|
|
|
540 fflush (stdout);
|
|
|
541 reset_initial_console ();
|
|
|
542 EMACS_UNBLOCK_SIGNAL (sig);
|
|
|
543 #ifdef SIGTSTP /* Support possible in later USG versions */
|
|
|
544 /*
|
|
|
545 * On systems which can suspend the current process and return to the original
|
|
|
546 * shell, this command causes the user to end up back at the shell.
|
|
|
547 * The "Auto-save" and "Abort" questions are not asked until
|
|
|
548 * the user elects to return to emacs, at which point he can save the current
|
|
|
549 * job and either dump core or continue.
|
|
|
550 */
|
|
|
551 sys_suspend ();
|
|
|
552 #else
|
|
|
553 /* Perhaps should really fork an inferior shell?
|
|
|
554 But that would not provide any way to get back
|
|
|
555 to the original shell, ever. */
|
|
|
556 stdout_out ("No support for stopping a process on this operating system;\n");
|
|
|
557 stdout_out ("you can continue or abort.\n");
|
|
|
558 #endif /* not SIGTSTP */
|
|
|
559 stdout_out ("Auto-save? (y or n) ");
|
|
|
560 if (((c = getc (stdin)) & ~040) == 'Y')
|
|
|
561 Fdo_auto_save (Qnil, Qnil);
|
|
|
562 while (c != '\n')
|
|
|
563 c = getc (stdin);
|
|
|
564 stdout_out ("Abort (and dump core)? (y or n) ");
|
|
|
565 if (((c = getc (stdin)) & ~040) == 'Y')
|
|
|
566 abort ();
|
|
|
567 while (c != '\n')
|
|
|
568 c = getc (stdin);
|
|
|
569 stdout_out ("Continuing...\n");
|
|
|
570 reinit_initial_console ();
|
|
|
571 MARK_FRAME_CHANGED (XFRAME (DEVICE_SELECTED_FRAME
|
|
|
572 (XDEVICE (CONSOLE_SELECTED_DEVICE
|
|
|
573 (XCONSOLE
|
|
|
574 (Vcontrolling_terminal))))));
|
|
|
575 }
|
|
|
576 else
|
|
|
577 {
|
|
|
578 /* Else request quit when it's safe */
|
|
|
579 Vquit_flag = Qt;
|
|
|
580 sigint_happened = 1;
|
|
|
581 #ifdef HAVE_UNIXOID_EVENT_LOOP
|
|
|
582 signal_fake_event ();
|
|
|
583 #endif
|
|
|
584 }
|
|
|
585 errno = old_errno;
|
|
|
586 SIGRETURN;
|
|
|
587 }
|
|
|
588
|
|
593
|
589
|
|
|
590 /**********************************************************************/
|
|
|
591 /* Control-G checking */
|
|
|
592 /**********************************************************************/
|
|
|
593
|
|
428
|
594 static Lisp_Object
|
|
|
595 restore_dont_check_for_quit (Lisp_Object val)
|
|
|
596 {
|
|
|
597 dont_check_for_quit = XINT (val);
|
|
|
598 return Qnil;
|
|
|
599 }
|
|
|
600
|
|
|
601 void
|
|
|
602 begin_dont_check_for_quit (void)
|
|
|
603 {
|
|
|
604 specbind (Qinhibit_quit, Qt);
|
|
|
605 record_unwind_protect (restore_dont_check_for_quit,
|
|
|
606 make_int (dont_check_for_quit));
|
|
|
607 dont_check_for_quit = 1;
|
|
|
608 }
|
|
|
609
|
|
|
610 /* The effect of this function is to set Vquit_flag if the user pressed
|
|
|
611 ^G and discard the ^G, so as to not notice the same ^G again. */
|
|
|
612 int
|
|
|
613 check_quit (void)
|
|
|
614 {
|
|
|
615 /* dont_check_for_quit is set in two circumstances:
|
|
|
616
|
|
|
617 (1) when we are in the process of changing the window
|
|
|
618 configuration. The frame might be in an inconsistent state,
|
|
|
619 which will cause assertion failures if we check for QUIT.
|
|
|
620
|
|
|
621 (2) when we are reading events, and want to read the C-g
|
|
|
622 as an event. The normal check for quit will discard the C-g,
|
|
|
623 which would be bad.
|
|
|
624
|
|
|
625 #### C-g is still often read as quit, e.g. if you type C-x C-g
|
|
|
626 (the C-g happens during the sit-for in maybe_echo_keys(); even
|
|
|
627 if we attempt to inhibit quit here, there is still a check
|
|
|
628 later on for QUIT. To fix this properly requires a fairly
|
|
|
629 substantial overhaul of the quit-checking code, which is
|
|
|
630 probably not worth it.)
|
|
|
631
|
|
|
632 We should *not* conditionalize on Vinhibit_quit, or
|
|
|
633 critical-quit (Control-Shift-G) won't work right. */
|
|
|
634
|
|
|
635 if (dont_check_for_quit)
|
|
|
636 return 0;
|
|
|
637
|
|
|
638 if (quit_check_signal_happened)
|
|
|
639 {
|
|
|
640 quit_check_signal_happened = 0;
|
|
|
641 event_stream_quit_p ();
|
|
|
642 return 1;
|
|
|
643 }
|
|
|
644 else
|
|
|
645 return 0;
|
|
|
646 }
|
|
|
647
|
|
|
648
|
|
|
649
|
|
|
650 void
|
|
|
651 init_poll_for_quit (void)
|
|
|
652 {
|
|
|
653 #if !defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)
|
|
|
654 /* Check for C-g every 1/4 of a second.
|
|
|
655
|
|
|
656 #### This is just a guess. Some investigation will have to be
|
|
|
657 done to see what the best value is. The best value is the
|
|
|
658 smallest possible value that doesn't cause a significant amount
|
|
|
659 of running time to be spent in C-g checking. */
|
|
|
660 if (!poll_for_quit_id)
|
|
|
661 poll_for_quit_id =
|
|
|
662 event_stream_generate_wakeup (NORMAL_QUIT_CHECK_TIMEOUT_MSECS,
|
|
|
663 NORMAL_QUIT_CHECK_TIMEOUT_MSECS,
|
|
|
664 Qnil, Qnil, 1);
|
|
|
665 #endif /* not SIGIO and not DONT_POLL_FOR_QUIT */
|
|
|
666 }
|
|
|
667
|
|
593
|
668 #if 0 /* not used anywhere */
|
|
|
669
|
|
428
|
670 void
|
|
|
671 reset_poll_for_quit (void)
|
|
|
672 {
|
|
|
673 #if !defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)
|
|
|
674 if (poll_for_quit_id)
|
|
|
675 {
|
|
|
676 event_stream_disable_wakeup (poll_for_quit_id, 1);
|
|
|
677 poll_for_quit_id = 0;
|
|
|
678 }
|
|
|
679 #endif /* not SIGIO and not DONT_POLL_FOR_QUIT */
|
|
|
680 }
|
|
|
681
|
|
593
|
682 #endif /* 0 */
|
|
|
683
|
|
428
|
684 #if defined(HAVE_UNIX_PROCESSES) && !defined(SIGCHLD)
|
|
|
685
|
|
|
686 static void
|
|
|
687 init_poll_for_sigchld (void)
|
|
|
688 {
|
|
|
689 /* Check for terminated processes every 1/4 of a second.
|
|
|
690
|
|
|
691 #### This is just a guess. Some investigation will have to be
|
|
|
692 done to see what the best value is. The best value is the
|
|
|
693 smallest possible value that doesn't cause a significant amount
|
|
|
694 of running time to be spent in process-termination checking.
|
|
|
695 */
|
|
|
696 poll_for_sigchld_id =
|
|
|
697 event_stream_generate_wakeup (NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS,
|
|
|
698 NORMAL_SIGCHLD_CHECK_TIMEOUT_MSECS,
|
|
|
699 Qnil, Qnil, 1);
|
|
|
700 }
|
|
|
701
|
|
|
702 #endif /* not SIGCHLD */
|
|
|
703
|
|
|
704
|
|
|
705 /************************************************************************/
|
|
|
706 /* initialization */
|
|
|
707 /************************************************************************/
|
|
|
708
|
|
|
709 /* If we've been nohup'ed, keep it that way.
|
|
|
710 This allows `nohup xemacs &' to work.
|
|
|
711 More generally, if a normally fatal signal has been redirected
|
|
|
712 to SIG_IGN by our invocation environment, trust the environment.
|
|
|
713 This keeps xemacs from being killed by a SIGQUIT intended for a
|
|
|
714 different process after having been backgrounded under a
|
|
|
715 non-job-control shell! */
|
|
|
716 static void
|
|
|
717 handle_signal_if_fatal (int signo)
|
|
|
718 {
|
|
|
719 if (signal (signo, fatal_error_signal) == SIG_IGN)
|
|
|
720 signal (signo, SIG_IGN);
|
|
|
721 }
|
|
|
722
|
|
|
723 void
|
|
|
724 init_signals_very_early (void)
|
|
|
725 {
|
|
|
726 /* Catch all signals that would kill us.
|
|
|
727 Don't catch these signals in batch mode if not initialized.
|
|
|
728 On some machines, this sets static data that would make
|
|
|
729 signal fail to work right when the dumped Emacs is run. */
|
|
|
730 if (noninteractive && !initialized)
|
|
|
731 return;
|
|
|
732
|
|
|
733 handle_signal_if_fatal (SIGILL); /* ANSI */
|
|
|
734 handle_signal_if_fatal (SIGABRT); /* ANSI */
|
|
|
735 handle_signal_if_fatal (SIGFPE); /* ANSI */
|
|
|
736 handle_signal_if_fatal (SIGSEGV); /* ANSI */
|
|
|
737 handle_signal_if_fatal (SIGTERM); /* ANSI */
|
|
|
738
|
|
|
739
|
|
|
740 #ifdef SIGHUP
|
|
|
741 handle_signal_if_fatal (SIGHUP); /* POSIX */
|
|
|
742 #endif
|
|
|
743 #ifdef SIGQUIT
|
|
|
744 handle_signal_if_fatal (SIGQUIT); /* POSIX */
|
|
|
745 #endif
|
|
|
746 #ifdef SIGTRAP
|
|
|
747 handle_signal_if_fatal (SIGTRAP); /* POSIX */
|
|
|
748 #endif
|
|
|
749 #ifdef SIGUSR1
|
|
|
750 handle_signal_if_fatal (SIGUSR1); /* POSIX */
|
|
|
751 #endif
|
|
|
752 #ifdef SIGUSR2
|
|
|
753 handle_signal_if_fatal (SIGUSR2); /* POSIX */
|
|
|
754 #endif
|
|
|
755 #ifdef SIGPIPE
|
|
|
756 handle_signal_if_fatal (SIGPIPE); /* POSIX */
|
|
|
757 #endif
|
|
|
758 #ifdef SIGALRM
|
|
|
759 /* This will get reset later, once we're
|
|
|
760 capable of handling it properly. */
|
|
|
761 handle_signal_if_fatal (SIGALRM); /* POSIX */
|
|
|
762 #endif
|
|
|
763
|
|
|
764
|
|
|
765 #ifdef SIGBUS
|
|
|
766 handle_signal_if_fatal (SIGBUS); /* XPG5 */
|
|
|
767 #endif
|
|
|
768 #ifdef SIGSYS
|
|
|
769 handle_signal_if_fatal (SIGSYS); /* XPG5 */
|
|
|
770 #endif
|
|
|
771 #ifdef SIGXCPU
|
|
|
772 handle_signal_if_fatal (SIGXCPU); /* XPG5 */
|
|
|
773 #endif
|
|
|
774 #ifdef SIGXFSZ
|
|
|
775 handle_signal_if_fatal (SIGXFSZ); /* XPG5 */
|
|
|
776 #endif
|
|
|
777 #ifdef SIGVTALRM
|
|
|
778 handle_signal_if_fatal (SIGVTALRM); /* XPG5 */
|
|
|
779 #endif
|
|
|
780 #ifdef SIGPROF
|
|
|
781 /* Messes up the REAL profiler */
|
|
|
782 /* handle_signal_if_fatal (SIGPROF); */ /* XPG5 */
|
|
|
783 #endif
|
|
|
784
|
|
|
785
|
|
|
786 #ifdef SIGHWE
|
|
|
787 handle_signal_if_fatal (SIGHWE);
|
|
|
788 #endif
|
|
|
789 #ifdef SIGPRE
|
|
|
790 handle_signal_if_fatal (SIGPRE);
|
|
|
791 #endif
|
|
|
792 #ifdef SIGORE
|
|
|
793 handle_signal_if_fatal (SIGORE);
|
|
|
794 #endif
|
|
|
795 #ifdef SIGUME
|
|
|
796 handle_signal_if_fatal (SIGUME);
|
|
|
797 #endif
|
|
|
798 #ifdef SIGDLK
|
|
|
799 handle_signal_if_fatal (SIGDLK);
|
|
|
800 #endif
|
|
|
801 #ifdef SIGCPULIM
|
|
|
802 handle_signal_if_fatal (SIGCPULIM);
|
|
|
803 #endif
|
|
|
804 #ifdef SIGIOT
|
|
|
805 handle_signal_if_fatal (SIGIOT);
|
|
|
806 #endif
|
|
|
807 #ifdef SIGEMT
|
|
|
808 handle_signal_if_fatal (SIGEMT);
|
|
|
809 #endif
|
|
|
810 #ifdef SIGLOST
|
|
|
811 handle_signal_if_fatal (SIGLOST);
|
|
|
812 #endif
|
|
|
813 #ifdef SIGSTKFLT /* coprocessor stack fault under Linux */
|
|
|
814 handle_signal_if_fatal (SIGSTKFLT);
|
|
|
815 #endif
|
|
|
816 #ifdef SIGUNUSED /* exists under Linux, and will kill process! */
|
|
|
817 handle_signal_if_fatal (SIGUNUSED);
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818 #endif
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|
|
819
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|
|
820 #ifdef AIX
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|
821 /* 20 is SIGCHLD, 21 is SIGTTIN, 22 is SIGTTOU. */
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|
|
822 #ifndef _I386
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|
|
823 handle_signal_if_fatal (SIGIOINT);
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|
|
824 #endif
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|
|
825 handle_signal_if_fatal (SIGGRANT);
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|
|
826 handle_signal_if_fatal (SIGRETRACT);
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|
|
827 handle_signal_if_fatal (SIGSOUND);
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|
|
828 handle_signal_if_fatal (SIGMSG);
|
|
|
829 #endif /* AIX */
|
|
|
830
|
|
|
831 #ifdef SIGDANGER
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|
|
832 /* This just means available memory is getting low. */
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|
|
833 signal (SIGDANGER, memory_warning_signal);
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|
|
834 #endif
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|
|
835 }
|
|
|
836
|
|
|
837 void
|
|
|
838 syms_of_signal (void)
|
|
|
839 {
|
|
|
840 DEFSUBR (Fwaiting_for_user_input_p);
|
|
|
841 }
|
|
|
842
|
|
|
843 void
|
|
|
844 init_interrupts_late (void)
|
|
|
845 {
|
|
|
846 if (!noninteractive)
|
|
|
847 {
|
|
|
848 signal (SIGINT, interrupt_signal);
|
|
|
849 #ifdef HAVE_TERMIO
|
|
|
850 /* On systems with TERMIO, C-g is set up for both SIGINT and SIGQUIT
|
|
|
851 and we can't tell which one it will give us. */
|
|
|
852 signal (SIGQUIT, interrupt_signal);
|
|
|
853 #endif /* HAVE_TERMIO */
|
|
|
854 init_async_timeouts ();
|
|
|
855 #ifdef SIGIO
|
|
|
856 signal (SIGIO, input_available_signal);
|
|
|
857 # ifdef SIGPOLL /* XPG5 */
|
|
|
858 /* Some systems (e.g. Motorola SVR4) losingly have different
|
|
|
859 values for SIGIO and SIGPOLL, and send SIGPOLL instead of
|
|
|
860 SIGIO. On those same systems, an uncaught SIGPOLL kills the
|
|
|
861 process. */
|
|
|
862 signal (SIGPOLL, input_available_signal);
|
|
|
863 # endif
|
|
|
864 #elif !defined (DONT_POLL_FOR_QUIT)
|
|
|
865 init_poll_for_quit ();
|
|
|
866 #endif
|
|
|
867 }
|
|
|
868
|
|
|
869 #if defined(HAVE_UNIX_PROCESSES) && !defined(SIGCHLD)
|
|
|
870 init_poll_for_sigchld ();
|
|
|
871 #endif
|
|
|
872
|
|
|
873 EMACS_UNBLOCK_ALL_SIGNALS ();
|
|
|
874
|
|
|
875 interrupts_initted = 1;
|
|
|
876 }
|
|
|
877
|
