src/IOEngine_select.c

   1 /* IOEngine_select.c - IOMultiplexer
   2  * Copyright (C) 2012  Philipp Kreil (pk910)
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 #include "IOEngine.h"
  18 #include <errno.h>
  19 #include <time.h>
  20 #ifdef WIN32
  21 #define _WIN32_WINNT 0x501
  22 #include <windows.h>
  23 #include <winsock2.h>
  24 #else
  25 #include <string.h>
  26 #include <stdio.h>
  27 #endif
  28
  29 static int engine_select_timer_delay_fix;
  30
  31 static int engine_select_init() {
  32     engine_select_timer_delay_fix = 0;
  33     return 1;
  34 }
  35
  36 static void engine_select_add(struct IODescriptor *iofd) {
  37     #ifdef WIN32
  38     if(iofd->type == IOTYPE_STDIN)
  39         SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE),ENABLE_LINE_INPUT|ENABLE_ECHO_INPUT);
  40     #endif
  41     /* empty */
  42 }
  43
  44 static void engine_select_remove(struct IODescriptor *iofd) {
  45     /* empty */
  46 }
  47
  48 static void engine_select_update(struct IODescriptor *iofd) {
  49     /* empty */
  50 }
  51
  52 static void engine_select_loop(struct timeval *timeout) {
  53     fd_set read_fds;
  54     fd_set write_fds;
  55     unsigned int fds_size = 0;
  56     struct IODescriptor *iofd, *tmp_iofd;
  57     struct timeval now, tdiff;
  58     int select_result;
  59     int timer_fix;
  60
  61     gettimeofday(&now, NULL);
  62
  63     //clear fds
  64     FD_ZERO(&read_fds);
  65     FD_ZERO(&write_fds);
  66
  67     select_result = 0;
  68     for(iofd = first_descriptor; iofd; iofd = tmp_iofd) {
  69         tmp_iofd = iofd->next;
  70         if(iofd->type == IOTYPE_STDIN) {
  71             #ifdef WIN32
  72             //WIN32 doesn't support stdin within select
  73             //just try to read the single events from the console
  74             DWORD dwRead;
  75             INPUT_RECORD inRecords[128];
  76             unsigned int i;
  77             int read_bytes = 0;
  78             GetNumberOfConsoleInputEvents(GetStdHandle(STD_INPUT_HANDLE), &dwRead);
  79             if(dwRead)
  80                 ReadConsoleInput(GetStdHandle(STD_INPUT_HANDLE), &inRecords[0], 128, &dwRead);
  81             for (i = 0; i < dwRead; ++i) {
  82                 if (inRecords[i].EventType == KEY_EVENT) {
  83                     const char c = inRecords[i].Event.KeyEvent.uChar.AsciiChar;
  84                     if (inRecords[i].Event.KeyEvent.bKeyDown && c != 0) {
  85                         iofd->readbuf.buffer[iofd->readbuf.bufpos + read_bytes] = c;
  86                         read_bytes++;
  87                     }
  88                 }
  89             }
  90             if(read_bytes)
  91                 iohandler_events(iofd, read_bytes, 0);
  92             if(read_bytes >= 128) {
  93                 timeout->tv_sec = 0;
  94                 timeout->tv_usec = 1;
  95                 //minimal timeout
  96             } else {
  97                 timeout->tv_sec = 0;
  98                 timeout->tv_usec = 100000;
  99             }
 100             #else
 101             if(iofd->fd > fds_size)
 102                 fds_size = iofd->fd;
 103             FD_SET(iofd->fd, &read_fds);
 104             select_result++;
 105             #endif
 106         }
 107         else if(iofd->type == IOTYPE_SERVER || iofd->type == IOTYPE_CLIENT) {
 108             if(iofd->state == IO_CLOSED)
 109                 continue;
 110             if(iofd->fd > fds_size)
 111                 fds_size = iofd->fd;
 112             FD_SET(iofd->fd, &read_fds);
 113             select_result++;
 114             if(iohandler_wants_writes(iofd))
 115                 FD_SET(iofd->fd, &write_fds);
 116         }
 117     }
 118
 119     while(timer_priority) {
 120         tdiff.tv_sec = timer_priority->timeout.tv_sec - now.tv_sec;
 121         tdiff.tv_usec = timer_priority->timeout.tv_usec - now.tv_usec;
 122         if(tdiff.tv_sec < 0 || (tdiff.tv_sec == 0 && tdiff.tv_usec <= 0)) {
 123             if(timer_priority->constant_timeout) {
 124                 tdiff.tv_sec = 0;
 125                 iohandler_set_timeout(timer_priority, &tdiff);
 126                 iohandler_events(timer_priority, 0, 0);
 127             } else {
 128                 iohandler_events(timer_priority, 0, 0);
 129                 iohandler_close(timer_priority); //also sets timer_priority to the next timed element
 130             }
 131             continue;
 132         } else if(tdiff.tv_usec < 0) {
 133             tdiff.tv_sec--;
 134             tdiff.tv_usec += 1000000; //1 sec
 135         }
 136         if(timeval_is_smaler((&tdiff), timeout)) {
 137             timeout->tv_sec = tdiff.tv_sec;
 138             timeout->tv_usec = tdiff.tv_usec + engine_select_timer_delay_fix;
 139             if(timeout->tv_usec < 0) {
 140                 timeout->tv_sec--;
 141                 timeout->tv_usec += 1000000;
 142             }
 143         }
 144         break;
 145     }
 146
 147     if(select_result) {
 148         //select system call
 149         select_result = select(fds_size + 1, &read_fds, &write_fds, NULL, timeout);
 150     } else {
 151         #ifdef WIN32
 152         Sleep((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000) + 1);
 153         #else
 154         struct timespec usleep_time;
 155         usleep_time.tv_sec = timeout->tv_sec;
 156         usleep_time.tv_nsec = timeout->tv_usec * 1000;
 157         nanosleep(&usleep_time, NULL);
 158         #endif
 159     }
 160
 161     if (select_result < 0) {
 162         if (errno != EINTR) {
 163             iohandler_log(IOLOG_FATAL, "select() failed with errno %d %d: %s", select_result, errno, strerror(errno));
 164             return;
 165         }
 166     }
 167
 168     gettimeofday(&now, NULL);
 169
 170     //check all descriptors
 171     for(iofd = first_descriptor; iofd; iofd = tmp_iofd) {
 172         tmp_iofd = iofd->next;
 173         if(iofd->type == IOTYPE_SERVER || iofd->type == IOTYPE_CLIENT || iofd->type == IOTYPE_STDIN) {
 174             if(FD_ISSET(iofd->fd, &read_fds) || FD_ISSET(iofd->fd, &write_fds)) {
 175                 iohandler_events(iofd, FD_ISSET(iofd->fd, &read_fds), FD_ISSET(iofd->fd, &write_fds));
 176                 continue;
 177             }
 178         }
 179     }
 180
 181     //check timers
 182     while(timer_priority) {
 183         tdiff.tv_sec = timer_priority->timeout.tv_sec - now.tv_sec;
 184         tdiff.tv_usec = timer_priority->timeout.tv_usec - now.tv_usec;
 185         timer_fix = (tdiff.tv_sec * 1000000) + tdiff.tv_usec;
 186         if(timer_fix <= 100) {
 187             if(timer_fix + 100 < engine_select_timer_delay_fix || timer_fix - 100 > engine_select_timer_delay_fix) {
 188                 engine_select_timer_delay_fix = ((engine_select_timer_delay_fix * 19) + timer_fix) / 20;
 189                 iohandler_log(IOLOG_DEBUG, "timer delay fix set to: %d us", engine_select_timer_delay_fix);
 190             }
 191             if(timer_priority->constant_timeout) {
 192                 tdiff.tv_sec = 0;
 193                 iohandler_set_timeout(timer_priority, &tdiff);
 194                 iohandler_events(timer_priority, 0, 0);
 195             } else {
 196                 iohandler_events(timer_priority, 0, 0);
 197                 iohandler_close(timer_priority); //also sets timer_priority to the next timed element
 198             }
 199             continue;
 200         }
 201         break;
 202     }
 203
 204 }
 205
 206 static void engine_select_cleanup() {
 207     /* empty */
 208 }
 209
 210 struct IOEngine engine_select = {
 211     .name = "select",
 212     .init = engine_select_init,
 213     .add = engine_select_add,
 214     .remove = engine_select_remove,
 215     .update = engine_select_update,
 216     .loop = engine_select_loop,
 217     .cleanup = engine_select_cleanup,
 218 };