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 #ifdef WIN32
  20 #define _WIN32_WINNT 0x501
  21 #include <windows.h>
  22 #include <winsock2.h>
  23 #else
  24 #include <string.h>
  25 #include <stdio.h>
  26 #endif
  27
  28 static int engine_select_init() {
  29     /* empty */
  30     return 1;
  31 }
  32
  33 static void engine_select_add(struct IODescriptor *iofd) {
  34     #ifdef WIN32
  35     if(iofd->type == IOTYPE_STDIN)
  36         SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE),ENABLE_LINE_INPUT|ENABLE_ECHO_INPUT);
  37     #endif
  38     /* empty */
  39 }
  40
  41 static void engine_select_remove(struct IODescriptor *iofd) {
  42     /* empty */
  43 }
  44
  45 static void engine_select_update(struct IODescriptor *iofd) {
  46     /* empty */
  47 }
  48
  49 static void engine_select_loop(struct timeval *timeout) {
  50     fd_set read_fds;
  51     fd_set write_fds;
  52     unsigned int fds_size = 0;
  53     struct IODescriptor *iofd, *tmp_iofd;
  54     struct timeval now, tdiff;
  55     int select_result;
  56
  57     gettimeofday(&now, NULL);
  58
  59     //clear fds
  60     FD_ZERO(&read_fds);
  61     FD_ZERO(&write_fds);
  62
  63     for(iofd = first_descriptor; iofd; iofd = tmp_iofd) {
  64         tmp_iofd = iofd->next;
  65         if(iofd->type == IOTYPE_STDIN) {
  66             #ifdef WIN32
  67             //WIN32 doesn't support stdin within select
  68             //just try to read the single events from the console
  69             DWORD dwRead;
  70             INPUT_RECORD inRecords[128];
  71             unsigned int i;
  72             int read_bytes = 0;
  73             GetNumberOfConsoleInputEvents(GetStdHandle(STD_INPUT_HANDLE), &dwRead);
  74             if(dwRead)
  75                 ReadConsoleInput(GetStdHandle(STD_INPUT_HANDLE), &inRecords[0], 128, &dwRead);
  76             for (i = 0; i < dwRead; ++i) {
  77                 if (inRecords[i].EventType == KEY_EVENT) {
  78                     const char c = inRecords[i].Event.KeyEvent.uChar.AsciiChar;
  79                     if (inRecords[i].Event.KeyEvent.bKeyDown && c != 0) {
  80                         iofd->readbuf.buffer[iofd->readbuf.bufpos + read_bytes] = c;
  81                         read_bytes++;
  82                     }
  83                 }
  84             }
  85             if(read_bytes)
  86                 iohandler_events(iofd, read_bytes, 0);
  87             if(read_bytes >= 128) {
  88                 timeout->tv_sec = 0;
  89                 timeout->tv_usec = 1;
  90                 //minimal timeout
  91             } else {
  92                 timeout->tv_sec = 0;
  93                 timeout->tv_usec = 100000;
  94             }
  95             #else
  96             if(iofd->fd > fds_size)
  97                 fds_size = iofd->fd;
  98             FD_SET(iofd->fd, &read_fds);
  99             #endif
 100         }
 101         else if(iofd->type == IOTYPE_SERVER || iofd->type == IOTYPE_CLIENT) {
 102             if(iofd->state == IO_CLOSED)
 103                 continue;
 104             if(iofd->fd > fds_size)
 105                 fds_size = iofd->fd;
 106             FD_SET(iofd->fd, &read_fds);
 107             if(iohandler_wants_writes(iofd))
 108                 FD_SET(iofd->fd, &write_fds);
 109         }
 110     }
 111
 112     while(timer_priority) {
 113         tdiff.tv_sec = timer_priority->timeout.tv_sec - now.tv_sec;
 114         tdiff.tv_usec = timer_priority->timeout.tv_usec - now.tv_usec;
 115         if(tdiff.tv_sec < 0 || (tdiff.tv_sec == 0 && tdiff.tv_usec <= 0)) {
 116             iohandler_events(timer_priority, 0, 0);
 117             iohandler_close(timer_priority); //also sets timer_priority to the next timed element
 118             continue;
 119         } else if(tdiff.tv_usec < 0) {
 120             tdiff.tv_sec--;
 121             tdiff.tv_usec += 1000000; //1 sec
 122         }
 123         if(timeval_is_smaler((&tdiff), timeout)) {
 124             timeout->tv_sec = tdiff.tv_sec;
 125             timeout->tv_usec = tdiff.tv_usec;
 126         }
 127         break;
 128     }
 129
 130     //select system call
 131     select_result = select(fds_size + 1, &read_fds, &write_fds, NULL, timeout);
 132
 133     if (select_result < 0) {
 134         if (errno != EINTR) {
 135             iohandler_log(IOLOG_FATAL, "select() failed with errno %d %d: %s", select_result, errno, strerror(errno));
 136             return;
 137         }
 138     }
 139
 140     gettimeofday(&now, NULL);
 141
 142     //check all descriptors
 143     for(iofd = first_descriptor; iofd; iofd = tmp_iofd) {
 144         tmp_iofd = iofd->next;
 145         if(iofd->type == IOTYPE_SERVER || iofd->type == IOTYPE_CLIENT || iofd->type == IOTYPE_STDIN) {
 146             if(FD_ISSET(iofd->fd, &read_fds) || FD_ISSET(iofd->fd, &write_fds)) {
 147                 iohandler_events(iofd, FD_ISSET(iofd->fd, &read_fds), FD_ISSET(iofd->fd, &write_fds));
 148                 continue;
 149             }
 150         }
 151     }
 152
 153     //check timers
 154     while(timer_priority) {
 155         tdiff.tv_sec = timer_priority->timeout.tv_sec - now.tv_sec;
 156         tdiff.tv_usec = timer_priority->timeout.tv_usec - now.tv_usec;
 157         if(tdiff.tv_sec < 0 || (tdiff.tv_sec == 0 && tdiff.tv_usec <= 0)) {
 158             iohandler_events(timer_priority, 0, 0);
 159             iohandler_close(timer_priority); //also sets timer_priority to the next timed element
 160             continue;
 161         }
 162         break;
 163     }
 164
 165 }
 166
 167 static void engine_select_cleanup() {
 168     /* empty */
 169 }
 170
 171 struct IOEngine engine_select = {
 172     .name = "select",
 173     .init = engine_select_init,
 174     .add = engine_select_add,
 175     .remove = engine_select_remove,
 176     .update = engine_select_update,
 177     .loop = engine_select_loop,
 178     .cleanup = engine_select_cleanup,
 179 };