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 | |
21 | #include <sys/time.h> |
24 | #include <sys/time.h> |
22 | |
25 | |
23 | #include <algorithm> |
26 | #if 1 // older unices need these includes for select(2) |
24 | #include <functional> |
27 | # include <unistd.h> |
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28 | # include <sys/types.h> |
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29 | #endif |
25 | |
30 | |
26 | #include "slog.h" |
31 | // if the BSDs would at least be marginally POSIX-compatible.. *sigh* |
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32 | // until that happens, sys/select.h must come last |
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33 | #include <sys/select.h> |
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34 | |
27 | #include "iom.h" |
35 | #include "iom.h" |
28 | |
36 | |
29 | inline bool lowest_first (const time_watcher *a, const time_watcher *b) |
37 | // TSTAMP_MAX must still fit into a positive struct timeval |
30 | { |
38 | #define TSTAMP_MAX (double)(1UL<<31) |
31 | return a->at > b->at; |
39 | |
32 | } |
40 | // this is a dummy time watcher to ensure that the first |
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41 | // time watcher is _always_ valid, this gets rid of a lot |
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42 | // of null-pointer-checks |
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43 | // (must come _before_ iom is being defined) |
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44 | static struct tw0 : time_watcher { |
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45 | void cb (time_watcher &w) |
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46 | { |
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47 | // should never get called |
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48 | // reached end-of-time, or tstamp has a bogus definition, |
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49 | // or compiler initilization order broken, or somethine else :) |
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50 | abort (); |
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51 | } |
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52 | |
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53 | tw0() |
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54 | : time_watcher (this, &tw0::cb) |
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55 | { } |
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56 | } tw0; |
33 | |
57 | |
34 | tstamp NOW; |
58 | tstamp NOW; |
35 | |
59 | static bool iom_valid; |
36 | io_manager iom; |
60 | io_manager iom; |
37 | |
61 | |
38 | void time_watcher::set (tstamp when) |
62 | template<class watcher> |
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63 | void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue) |
39 | { |
64 | { |
40 | at = when; |
65 | if (!iom_valid) |
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66 | abort (); |
41 | |
67 | |
42 | if (registered) |
68 | if (!w->active) |
43 | iom.reschedule_time_watchers (); |
69 | { |
44 | else |
70 | #if IOM_CHECK |
45 | iom.reg (this); |
71 | queue.activity = true; |
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72 | #endif |
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73 | queue.push_back (w); |
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74 | w->active = queue.size (); |
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75 | } |
46 | } |
76 | } |
47 | |
77 | |
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78 | template<class watcher> |
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79 | void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue) |
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80 | { |
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81 | if (!iom_valid) |
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82 | return; |
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83 | |
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84 | if (w->active) |
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85 | { |
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86 | queue [w->active - 1] = 0; |
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87 | w->active = 0; |
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88 | } |
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89 | } |
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90 | |
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91 | #if IOM_TIME |
48 | void time_watcher::trigger () |
92 | void time_watcher::trigger () |
49 | { |
93 | { |
50 | call (at); |
94 | call (*this); |
51 | |
95 | |
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); |
96 | iom.reg (this); |
56 | } |
97 | } |
57 | |
98 | |
58 | void time_watcher::start () |
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59 | { |
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60 | if (!registered) |
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61 | iom.reg (this); |
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62 | } |
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63 | |
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64 | void io_manager::reg (int fd, short events, io_watcher *w) |
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65 | { |
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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) |
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76 | { |
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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 | |
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80 | if (i != sz) |
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81 | { |
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82 | if (sz == 1) |
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83 | { |
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84 | pfs.clear (); |
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85 | iow.clear (); |
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86 | } |
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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 | } |
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92 | else |
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93 | { |
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94 | iow[i] = iow[sz - 1]; iow.pop_back (); |
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95 | pfs[i] = pfs[sz - 1]; pfs.pop_back (); |
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96 | } |
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97 | } |
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98 | } |
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99 | |
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100 | void io_manager::reschedule_time_watchers () |
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101 | { |
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102 | make_heap (tw.begin (), tw.end (), lowest_first); |
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103 | } |
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104 | |
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105 | void io_manager::reg (time_watcher *w) |
99 | void io_manager::reg (time_watcher *w) { reg (w, tw); } |
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) |
100 | void io_manager::unreg (time_watcher *w) { unreg (w, tw); } |
117 | { |
101 | #endif |
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 | |
102 | |
123 | if (i != sz) |
103 | #if IOM_IO |
124 | { |
104 | void io_manager::reg (io_watcher *w) { reg (w, iow); } |
125 | if (i != sz - 1) |
105 | void io_manager::unreg (io_watcher *w) { unreg (w, iow); } |
126 | tw[i] = tw[sz - 1]; |
106 | #endif |
127 | |
107 | |
128 | tw.pop_back (); |
108 | #if IOM_CHECK |
129 | reschedule_time_watchers (); |
109 | void io_manager::reg (check_watcher *w) { reg (w, cw); } |
130 | } |
110 | void io_manager::unreg (check_watcher *w) { unreg (w, cw); } |
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111 | #endif |
131 | |
112 | |
132 | w->registered = false; |
113 | #if IOM_IDLE |
133 | } |
114 | void io_manager::reg (idle_watcher *w) { reg (w, iw); } |
134 | } |
115 | void io_manager::unreg (idle_watcher *w) { unreg (w, iw); } |
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116 | #endif |
135 | |
117 | |
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118 | #if IOM_TIME |
136 | inline void set_now (void) |
119 | inline void set_now (void) |
137 | { |
120 | { |
138 | struct timeval tv; |
121 | struct timeval tv; |
139 | |
122 | |
140 | gettimeofday (&tv, 0); |
123 | gettimeofday (&tv, 0); |
141 | |
124 | |
142 | NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; |
125 | NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; |
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126 | #endif |
143 | } |
127 | } |
144 | |
128 | |
145 | void io_manager::loop () |
129 | void io_manager::loop () |
146 | { |
130 | { |
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131 | #if IOM_TIME |
147 | set_now (); |
132 | set_now (); |
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133 | #endif |
148 | |
134 | |
149 | for (;;) |
135 | for (;;) |
150 | { |
136 | { |
151 | while (tw[0]->at <= NOW) |
137 | struct timeval *to = 0; |
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138 | struct timeval tval; |
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139 | |
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140 | #if IOM_IDLE |
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141 | if (iw.size ()) |
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142 | { |
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143 | tval.tv_sec = 0; |
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144 | tval.tv_usec = 0; |
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145 | to = &tval; |
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146 | } |
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147 | else |
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148 | #endif |
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149 | { |
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150 | #if IOM_TIME |
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151 | time_watcher *next; |
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152 | |
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153 | for (;;) |
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154 | { |
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155 | next = tw[0]; // the first time-watcher must exist at ALL times |
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156 | |
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157 | for (int i = tw.size (); i--; ) |
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158 | if (!tw[i]) |
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159 | tw.erase_unordered (i); |
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160 | else if (tw[i]->at < next->at) |
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161 | next = tw[i]; |
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162 | |
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163 | if (next->at > NOW) |
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164 | { |
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165 | if (next != tw[0]) |
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166 | { |
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167 | double diff = next->at - NOW; |
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168 | tval.tv_sec = (int)diff; |
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169 | tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000); |
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170 | to = &tval; |
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171 | } |
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172 | break; |
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173 | } |
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174 | else |
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175 | { |
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176 | unreg (next); |
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177 | next->call (*next); |
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178 | } |
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179 | } |
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180 | #endif |
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181 | } |
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182 | |
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183 | #if IOM_CHECK |
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184 | tw.activity = false; |
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185 | |
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186 | for (int i = cw.size (); i--; ) |
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187 | if (!cw[i]) |
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188 | cw.erase_unordered (i); |
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189 | else |
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190 | cw[i]->call (*cw[i]); |
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191 | |
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192 | if (tw.activity) |
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193 | { |
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194 | tval.tv_sec = 0; |
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195 | tval.tv_usec = 0; |
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196 | to = &tval; |
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197 | } |
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198 | #endif |
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199 | |
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200 | #if IOM_IO |
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201 | fd_set rfd, wfd, efd; |
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202 | |
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203 | FD_ZERO (&rfd); |
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204 | FD_ZERO (&wfd); |
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205 | |
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206 | int fds = 0; |
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207 | |
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208 | for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); ) |
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209 | if (*i) |
152 | { |
210 | { |
153 | // remove the first watcher |
211 | if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); |
154 | time_watcher *w = tw[0]; |
212 | if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); |
155 | |
213 | |
156 | pop_heap (tw.begin (), tw.end (), lowest_first); |
214 | if ((*i)->fd >= fds) fds = (*i)->fd + 1; |
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 | } |
215 | } |
168 | |
216 | |
169 | int timeout = (int) ((tw[0]->at - NOW) * 1000); |
217 | if (!to && !fds) //TODO: also check idle_watchers and check_watchers |
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218 | break; // no events |
170 | |
219 | |
171 | int fds = poll (&pfs[0], pfs.size (), timeout); |
220 | fds = select (fds, &rfd, &wfd, &efd, to); |
172 | |
221 | # if IOM_TIME |
173 | set_now (); |
222 | set_now (); |
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223 | # endif |
174 | |
224 | |
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225 | if (fds > 0) |
175 | for (unsigned int i = iow.size (); fds > 0 && i--; ) |
226 | for (int i = iow.size (); i--; ) |
176 | if (pfs[i].revents) |
227 | if (!iow[i]) |
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228 | iow.erase_unordered (i); |
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229 | else |
177 | { |
230 | { |
178 | --fds; |
231 | short revents = iow[i]->events; |
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232 | |
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233 | if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ; |
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234 | if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE; |
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235 | |
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236 | if (revents) |
179 | iow[i]->call (pfs[i].revents); |
237 | iow[i]->call (*iow[i], revents); |
180 | } |
238 | } |
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239 | else if (fds < 0 && errno != EINTR) |
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240 | { |
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241 | perror ("Error while waiting for I/O or time event"); |
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242 | abort (); |
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243 | } |
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244 | #if IOM_IDLE |
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245 | else |
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246 | for (int i = iw.size (); i--; ) |
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247 | if (!iw[i]) |
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248 | iw.erase_unordered (i); |
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249 | else |
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250 | iw[i]->call (*iw[i]); |
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251 | #endif |
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252 | |
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253 | #elif IOM_TIME |
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254 | if (!to) |
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255 | break; |
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256 | |
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257 | select (0, 0, 0, 0, &to); |
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258 | set_now (); |
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259 | #else |
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260 | break; |
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261 | #endif |
181 | } |
262 | } |
182 | } |
263 | } |
183 | |
264 | |
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 () |
265 | io_manager::io_manager () |
190 | { |
266 | { |
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267 | iom_valid = true; |
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268 | |
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269 | #if IOM_TIME |
191 | set_now (); |
270 | set_now (); |
192 | idle = new time_watcher (this, &io_manager::idle_cb); |
271 | |
193 | idle->start (0); |
272 | tw0.start (TSTAMP_MAX); |
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273 | #endif |
194 | } |
274 | } |
195 | |
275 | |
196 | io_manager::~io_manager () |
276 | io_manager::~io_manager () |
197 | { |
277 | { |
198 | // |
278 | iom_valid = false; |
199 | } |
279 | } |
200 | |
280 | |