lib/silcutil/unix/silcunixschedule.c

   1 /*
   2
   3   silcunixschedule.c
   4
   5   Author: Pekka Riikonen <priikone@silcnet.org>
   6
   7   Copyright (C) 1998 - 2001 Pekka Riikonen
   8
   9   This program is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published by
  11   the Free Software Foundation; either version 2 of the License, or
  12   (at your option) any later version.
  13
  14   This program is distributed in the hope that it will be useful,
  15   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17   GNU General Public License for more details.
  18
  19 */
  20 /* $Id$ */
  21
  22 #include "silcincludes.h"
  23 #include "silcschedule_i.h"
  24
  25 /* Calls normal select() system call. */
  26
  27 int silc_select(SilcScheduleFd fds, SilcUInt32 fds_count,
  28                 struct timeval *timeout)
  29 {
  30   fd_set in, out;
  31   int ret, i, max_fd = 0;
  32
  33   FD_ZERO(&in);
  34   FD_ZERO(&out);
  35
  36   for (i = 0; i < fds_count; i++) {
  37     if (!fds[i].events)
  38       continue;
  39
  40     if (fds[i].fd > max_fd)
  41       max_fd = fds[i].fd;
  42
  43     if (fds[i].events & SILC_TASK_READ)
  44       FD_SET(fds[i].fd, &in);
  45     if (fds[i].events & SILC_TASK_WRITE)
  46       FD_SET(fds[i].fd, &out);
  47
  48     fds[i].revents = 0;
  49   }
  50
  51   ret = select(max_fd + 1, &in, &out, NULL, timeout);
  52   if (ret <= 0)
  53     return ret;
  54
  55   for (i = 0; i < fds_count; i++) {
  56     if (!fds[i].events)
  57       continue;
  58
  59     if (FD_ISSET(fds[i].fd, &in))
  60       fds[i].revents |= SILC_TASK_READ;
  61     if (FD_ISSET(fds[i].fd, &out))
  62       fds[i].revents |= SILC_TASK_WRITE;
  63   }
  64
  65   return ret;
  66 }
  67
  68 #define SIGNAL_COUNT 32
  69
  70 typedef struct {
  71   SilcUInt32 signal;
  72   SilcTaskCallback callback;
  73   void *context;
  74   bool call;
  75 } SilcUnixSignal;
  76
  77 /* Internal context. */
  78 typedef struct {
  79   int wakeup_pipe[2];
  80   SilcTask wakeup_task;
  81   sigset_t signals;
  82   sigset_t signals_blocked;
  83   SilcUnixSignal signal_call[SIGNAL_COUNT];
  84 } *SilcUnixScheduler;
  85
  86 #ifdef SILC_THREADS
  87
  88 SILC_TASK_CALLBACK(silc_schedule_wakeup_cb)
  89 {
  90   SilcUnixScheduler internal = (SilcUnixScheduler)context;
  91   unsigned char c;
  92
  93   read(internal->wakeup_pipe[0], &c, 1);
  94 }
  95
  96 #endif /* SILC_THREADS */
  97
  98 /* Initializes the platform specific scheduler.  This for example initializes
  99    the wakeup mechanism of the scheduler.  In multi-threaded environment
 100    the scheduler needs to be wakenup when tasks are added or removed from
 101    the task queues.  Returns context to the platform specific scheduler. */
 102
 103 void *silc_schedule_internal_init(SilcSchedule schedule)
 104 {
 105   SilcUnixScheduler internal;
 106
 107   internal = silc_calloc(1, sizeof(*internal));
 108   if (!internal)
 109     return NULL;
 110
 111   sigemptyset(&internal->signals);
 112
 113 #ifdef SILC_THREADS
 114   if (pipe(internal->wakeup_pipe)) {
 115     silc_free(internal);
 116     return NULL;
 117   }
 118
 119   internal->wakeup_task =
 120     silc_schedule_task_add(schedule, internal->wakeup_pipe[0],
 121                            silc_schedule_wakeup_cb, internal,
 122                            0, 0, SILC_TASK_FD,
 123                            SILC_TASK_PRI_NORMAL);
 124   if (!internal->wakeup_task) {
 125     close(internal->wakeup_pipe[0]);
 126     close(internal->wakeup_pipe[1]);
 127     silc_free(internal);
 128     return NULL;
 129   }
 130 #endif
 131
 132   return (void *)internal;
 133 }
 134
 135 /* Uninitializes the platform specific scheduler context. */
 136
 137 void silc_schedule_internal_uninit(void *context)
 138 {
 139   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 140
 141   if (!internal)
 142     return;
 143
 144 #ifdef SILC_THREADS
 145   close(internal->wakeup_pipe[0]);
 146   close(internal->wakeup_pipe[1]);
 147 #endif
 148
 149   silc_free(internal);
 150 }
 151
 152 /* Wakes up the scheduler */
 153
 154 void silc_schedule_internal_wakeup(void *context)
 155 {
 156 #ifdef SILC_THREADS
 157   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 158
 159   if (!internal)
 160     return;
 161
 162   write(internal->wakeup_pipe[1], "!", 1);
 163 #endif
 164 }
 165
 166 void silc_schedule_internal_signal_register(void *context,
 167                                             SilcUInt32 signal,
 168                                             SilcTaskCallback callback,
 169                                             void *callback_context)
 170 {
 171   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 172   int i;
 173
 174   for (i = 0; i < SIGNAL_COUNT; i++) {
 175     if (!internal->signal_call[i].signal) {
 176       internal->signal_call[i].signal = signal;
 177       internal->signal_call[i].callback = callback;
 178       internal->signal_call[i].context = callback_context;
 179       internal->signal_call[i].call = FALSE;
 180     }
 181   }
 182
 183   sigaddset(&internal->signals, signal);
 184 }
 185
 186 void silc_schedule_internal_signal_unregister(void *context,
 187                                               SilcUInt32 signal,
 188                                               SilcTaskCallback callback,
 189                                               void *callback_context)
 190 {
 191   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 192   int i;
 193
 194   for (i = 0; i < SIGNAL_COUNT; i++) {
 195     if (internal->signal_call[i].signal == signal &&
 196         internal->signal_call[i].callback == callback &&
 197         internal->signal_call[i].context == callback_context) {
 198       internal->signal_call[i].signal = 0;
 199       internal->signal_call[i].callback = NULL;
 200       internal->signal_call[i].context = NULL;
 201       internal->signal_call[i].call = FALSE;
 202     }
 203   }
 204
 205   sigdelset(&internal->signals, signal);
 206 }
 207
 208 /* Mark signal to be called later. */
 209
 210 void silc_schedule_internal_signal_call(void *context, SilcUInt32 signal)
 211 {
 212   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 213   int i;
 214
 215   for (i = 0; i < SIGNAL_COUNT; i++) {
 216     if (internal->signal_call[i].signal == signal)
 217       internal->signal_call[i].call = TRUE;
 218   }
 219 }
 220
 221 /* Call all signals */
 222
 223 void silc_schedule_internal_signals_call(void *context,
 224                                          SilcSchedule schedule)
 225 {
 226   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 227   int i;
 228
 229   for (i = 0; i < SIGNAL_COUNT; i++) {
 230     if (internal->signal_call[i].call &&
 231         internal->signal_call[i].callback) {
 232       internal->signal_call[i].callback(schedule, SILC_TASK_INTERRUPT,
 233                                         internal->signal_call[i].signal,
 234                                         internal->signal_call[i].context);
 235       internal->signal_call[i].call = FALSE;
 236     }
 237   }
 238 }
 239
 240 /* Block registered signals in scheduler. */
 241
 242 void silc_schedule_internal_signals_block(void *context)
 243 {
 244   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 245   sigprocmask(SIG_BLOCK, &internal->signals, &internal->signals_blocked);
 246 }
 247
 248 /* Unblock registered signals in schedule. */
 249
 250 void silc_schedule_internal_signals_unblock(void *context)
 251 {
 252   SilcUnixScheduler internal = (SilcUnixScheduler)context;
 253   sigprocmask(SIG_SETMASK, &internal->signals_blocked, NULL);
 254 }