1 | /* |
1 | /* |
2 | iom.C -- I/O multiplexor |
2 | iom.C -- generic I/O multiplexor |
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3 | Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com> |
3 | |
4 | |
4 | This program is free software; you can redistribute it and/or modify |
5 | 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 | it under the terms of the GNU General Public License as published by |
6 | the Free Software Foundation; either version 2 of the License, or |
7 | the Free Software Foundation; either version 2 of the License, or |
7 | (at your option) any later version. |
8 | (at your option) any later version. |
… | |
… | |
14 | You should have received a copy of the GNU General Public License |
15 | You should have received a copy of the GNU General Public License |
15 | along with this program; if not, write to the Free Software |
16 | along with this program; if not, write to the Free Software |
16 | Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
17 | Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
17 | */ |
18 | */ |
18 | |
19 | |
19 | #include "config.h" |
20 | #include <cstdio> |
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21 | #include <cstdlib> |
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22 | #include <cerrno> |
20 | |
23 | |
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24 | #include <sys/select.h> |
21 | #include <sys/time.h> |
25 | #include <sys/time.h> |
22 | |
26 | |
23 | #include <algorithm> |
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24 | #include <functional> |
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25 | |
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26 | #include "slog.h" |
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27 | #include "iom.h" |
27 | #include "iom.h" |
28 | |
28 | |
29 | inline bool lowest_first (const time_watcher *a, const time_watcher *b) |
29 | // TSTAMP_MAX must still fit into a positive struct timeval |
30 | { |
30 | #define TSTAMP_MAX (double)(1UL<<31) |
31 | return a->at > b->at; |
31 | |
32 | } |
32 | // this is a dummy time watcher to ensure that the first |
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33 | // time watcher is _always_ valid, this gets rid of a lot |
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34 | // of null-pointer-checks |
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35 | // (must come _before_ iom is being defined) |
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36 | static struct tw0 : time_watcher { |
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37 | void cb (time_watcher &w) |
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38 | { |
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39 | // should never get called |
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40 | // reached end-of-time, or tstamp has a bogus definition, |
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41 | // or compiler initilization order broken, or somethine else :) |
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42 | abort (); |
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43 | } |
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44 | |
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45 | tw0() |
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46 | : time_watcher (this, &tw0::cb) |
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47 | { } |
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48 | } tw0; |
33 | |
49 | |
34 | tstamp NOW; |
50 | tstamp NOW; |
35 | |
51 | static bool iom_valid; |
36 | io_manager iom; |
52 | io_manager iom; |
37 | |
53 | |
38 | void time_watcher::set (tstamp when) |
54 | template<class watcher> |
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55 | void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue) |
39 | { |
56 | { |
40 | at = when; |
57 | if (!iom_valid) |
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58 | abort (); |
41 | |
59 | |
42 | if (registered) |
60 | if (!w->active) |
43 | iom.reschedule_time_watchers (); |
61 | { |
44 | else |
62 | queue.push_back (w); |
45 | iom.reg (this); |
63 | w->active = queue.size (); |
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64 | } |
46 | } |
65 | } |
47 | |
66 | |
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67 | template<class watcher> |
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68 | void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue) |
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69 | { |
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70 | if (!iom_valid) |
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71 | return; |
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72 | |
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73 | if (w->active) |
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74 | { |
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75 | queue [w->active - 1] = 0; |
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76 | w->active = 0; |
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77 | } |
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78 | } |
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79 | |
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80 | #if IOM_TIME |
48 | void time_watcher::trigger () |
81 | void time_watcher::trigger () |
49 | { |
82 | { |
50 | call (at); |
83 | call (*this); |
51 | |
84 | |
52 | if (registered) |
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53 | iom.reschedule_time_watchers (); |
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54 | else |
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55 | iom.reg (this); |
85 | iom.reg (this); |
56 | } |
86 | } |
57 | |
87 | |
58 | void time_watcher::start () |
88 | void io_manager::reg (time_watcher *w) { reg (w, tw); } |
59 | { |
89 | void io_manager::unreg (time_watcher *w) { unreg (w, tw); } |
60 | if (!registered) |
90 | #endif |
61 | iom.reg (this); |
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62 | } |
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63 | |
91 | |
64 | void io_manager::reg (int fd, short events, io_watcher *w) |
92 | #if IOM_IO |
65 | { |
93 | void io_manager::reg (io_watcher *w) { reg (w, iow); } |
66 | pollfd pfd; |
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67 | |
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68 | pfd.fd = fd; |
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69 | pfd.events = events; |
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70 | |
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71 | pfs.push_back (pfd); |
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72 | iow.push_back (w); |
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73 | } |
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74 | |
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75 | void io_manager::unreg (io_watcher *w) |
94 | void io_manager::unreg (io_watcher *w) { unreg (w, iow); } |
76 | { |
95 | #endif |
77 | unsigned int sz = iow.size (); |
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78 | unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin (); |
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79 | |
96 | |
80 | if (i != sz) |
97 | #if IOM_CHECK |
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98 | void io_manager::reg (check_watcher *w) { reg (w, cw); } |
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99 | void io_manager::unreg (check_watcher *w) { unreg (w, cw); } |
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100 | #endif |
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101 | |
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102 | #if IOM_IDLE |
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103 | void io_manager::reg (idle_watcher *w) { reg (w, iw); } |
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104 | void io_manager::unreg (idle_watcher *w) { unreg (w, iw); } |
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105 | #endif |
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106 | |
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107 | #if IOM_TIME |
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108 | inline void set_now (void) |
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109 | { |
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110 | struct timeval tv; |
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111 | |
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112 | gettimeofday (&tv, 0); |
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113 | |
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114 | NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; |
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115 | #endif |
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116 | } |
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117 | |
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118 | void io_manager::loop () |
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119 | { |
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120 | #if IOM_TIME |
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121 | set_now (); |
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122 | #endif |
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123 | |
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124 | for (;;) |
81 | { |
125 | { |
82 | if (sz == 1) |
126 | struct timeval *to = 0; |
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127 | struct timeval tval; |
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128 | |
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129 | #if IOM_IDLE |
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130 | if (iw.size ()) |
83 | { |
131 | { |
84 | pfs.clear (); |
132 | tval.tv_sec = 0; |
85 | iow.clear (); |
133 | tval.tv_usec = 0; |
86 | } |
134 | to = &tval; |
87 | else if (i == sz - 1) |
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88 | { |
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89 | iow.pop_back (); |
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90 | pfs.pop_back (); |
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91 | } |
135 | } |
92 | else |
136 | else |
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137 | #endif |
93 | { |
138 | { |
94 | iow[i] = iow[sz - 1]; iow.pop_back (); |
139 | #if IOM_TIME |
95 | pfs[i] = pfs[sz - 1]; pfs.pop_back (); |
140 | time_watcher *next; |
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141 | |
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142 | for (;;) |
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143 | { |
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144 | next = tw[0]; // the first time-watcher must exist at ALL times |
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145 | |
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146 | for (int i = tw.size (); i--; ) |
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147 | if (!tw[i]) |
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148 | tw.erase_unordered (i); |
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149 | else if (tw[i]->at < next->at) |
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150 | next = tw[i]; |
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151 | |
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152 | if (next->at > NOW) |
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153 | { |
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154 | if (next != tw[0]) |
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155 | { |
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156 | double diff = next->at - NOW; |
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157 | tval.tv_sec = (int)diff; |
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158 | tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000); |
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159 | to = &tval; |
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160 | } |
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161 | break; |
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162 | } |
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163 | else |
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164 | { |
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165 | unreg (next); |
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166 | next->call (*next); |
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167 | } |
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168 | } |
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169 | #endif |
96 | } |
170 | } |
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171 | |
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172 | #if IOM_CHECK |
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173 | for (int i = cw.size (); i--; ) |
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174 | if (!cw[i]) |
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175 | cw.erase_unordered (i); |
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176 | else |
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177 | cw[i]->call (*cw[i]); |
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178 | #endif |
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179 | |
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180 | #if IOM_IO |
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181 | fd_set rfd, wfd, efd; |
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182 | |
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183 | FD_ZERO (&rfd); |
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184 | FD_ZERO (&wfd); |
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185 | |
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186 | int fds = 0; |
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187 | |
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188 | for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); ) |
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189 | if (*i) |
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190 | { |
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191 | if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); |
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192 | if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); |
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193 | |
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194 | if ((*i)->fd >= fds) fds = (*i)->fd + 1; |
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195 | } |
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196 | |
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197 | if (!to && !fds) //TODO: also check idle_watchers and check_watchers |
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198 | break; // no events |
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199 | |
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200 | fds = select (fds, &rfd, &wfd, &efd, to); |
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201 | # if IOM_TIME |
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202 | set_now (); |
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203 | # endif |
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204 | |
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205 | if (fds > 0) |
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206 | for (int i = iow.size (); i--; ) |
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207 | if (!iow[i]) |
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208 | iow.erase_unordered (i); |
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209 | else |
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210 | { |
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211 | short revents = iow[i]->events; |
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212 | |
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213 | if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ; |
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214 | if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE; |
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215 | |
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216 | if (revents) |
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217 | iow[i]->call (*iow[i], revents); |
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218 | } |
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219 | else if (fds < 0 && errno != EINTR) |
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220 | { |
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221 | perror ("Error while waiting for I/O or time event"); |
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222 | abort (); |
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223 | } |
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224 | #if IOM_IDLE |
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225 | else |
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226 | for (int i = iw.size (); i--; ) |
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227 | if (!iw[i]) |
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228 | iw.erase_unordered (i); |
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229 | else |
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230 | iw[i]->call (*iw[i]); |
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231 | #endif |
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232 | |
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233 | #elif IOM_TIME |
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234 | if (!to) |
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235 | break; |
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236 | |
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237 | select (0, 0, 0, 0, &to); |
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238 | set_now (); |
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239 | #else |
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240 | break; |
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241 | #endif |
97 | } |
242 | } |
98 | } |
243 | } |
99 | |
244 | |
100 | void io_manager::reschedule_time_watchers () |
245 | io_manager::io_manager () |
101 | { |
246 | { |
102 | make_heap (tw.begin (), tw.end (), lowest_first); |
247 | iom_valid = true; |
103 | } |
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104 | |
248 | |
105 | void io_manager::reg (time_watcher *w) |
249 | #if IOM_TIME |
106 | { |
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107 | if (w->registered) |
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108 | slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher"); |
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109 | |
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110 | w->registered = true; |
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111 | |
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112 | tw.push_back (w); |
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113 | push_heap (tw.begin (), tw.end (), lowest_first); |
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114 | } |
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115 | |
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116 | void io_manager::unreg (time_watcher *w) |
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117 | { |
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118 | if (w->registered) |
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119 | { |
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120 | unsigned int sz = tw.size (); |
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121 | unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin (); |
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122 | |
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123 | if (i != sz) |
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124 | { |
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125 | if (i != sz - 1) |
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126 | tw[i] = tw[sz - 1]; |
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127 | |
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128 | tw.pop_back (); |
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129 | reschedule_time_watchers (); |
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130 | } |
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131 | |
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132 | w->registered = false; |
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133 | } |
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134 | } |
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135 | |
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136 | inline void set_now (void) |
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137 | { |
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138 | struct timeval tv; |
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139 | |
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140 | gettimeofday (&tv, 0); |
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141 | |
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142 | NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; |
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143 | } |
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144 | |
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145 | void io_manager::loop () |
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146 | { |
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147 | set_now (); |
250 | set_now (); |
148 | |
251 | |
149 | for (;;) |
252 | tw0.start (TSTAMP_MAX); |
150 | { |
253 | printf ("abort, %f but inly on %f\n", NOW, tw0.at); |
151 | while (tw[0]->at <= NOW) |
254 | #endif |
152 | { |
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153 | // remove the first watcher |
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154 | time_watcher *w = tw[0]; |
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155 | |
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156 | pop_heap (tw.begin (), tw.end (), lowest_first); |
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157 | tw.pop_back (); |
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158 | |
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159 | w->registered = false; |
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160 | |
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161 | // call it |
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162 | w->call (w->at); |
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163 | |
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164 | // re-add it if necessary |
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165 | if (w->at >= 0 && !w->registered) |
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166 | reg (w); |
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167 | } |
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168 | |
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169 | int timeout = (int) ((tw[0]->at - NOW) * 1000); |
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170 | |
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171 | int fds = poll (&pfs[0], pfs.size (), timeout); |
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172 | |
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173 | set_now (); |
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174 | |
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175 | for (unsigned int i = iow.size (); fds > 0 && i--; ) |
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176 | if (pfs[i].revents) |
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177 | { |
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178 | --fds; |
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179 | iow[i]->call (pfs[i].revents); |
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180 | } |
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181 | } |
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182 | } |
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183 | |
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184 | void io_manager::idle_cb (tstamp &ts) |
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185 | { |
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186 | ts = NOW + 86400; // wake up every day, for no good reason |
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187 | } |
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188 | |
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189 | io_manager::io_manager () |
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190 | { |
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191 | set_now (); |
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192 | idle = new time_watcher (this, &io_manager::idle_cb); |
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193 | idle->start (0); |
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194 | } |
255 | } |
195 | |
256 | |
196 | io_manager::~io_manager () |
257 | io_manager::~io_manager () |
197 | { |
258 | { |
198 | // |
259 | iom_valid = false; |
199 | } |
260 | } |
200 | |
261 | |