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Comparing gvpe/src/iom.C (file contents):
Revision 1.8 by pcg, Wed Apr 2 05:15:00 2003 UTC vs.
Revision 1.19 by pcg, Sun Mar 28 01:53:33 2004 UTC

1/* 1/*
2 iom.C -- I/O multiplexor 2 iom.C -- generic I/O multiplexor
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>
21#include <cstdlib>
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>
28# include <sys/types.h>
29#endif
25 30
26#include "slog.h" 31// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
32// until that happens, sys/select.h must come last
33#include <sys/select.h>
34
27#include "iom.h" 35#include "iom.h"
28 36
29inline 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
41// time watcher is _always_ valid, this gets rid of a lot
42// of null-pointer-checks
43// (must come _before_ iom is being defined)
44static struct tw0 : time_watcher
45 {
46 void cb (time_watcher &w)
47 {
48 // should never get called
49 // reached end-of-time, or tstamp has a bogus definition,
50 // or compiler initilization order broken, or somethine else :)
51 abort ();
52 }
53
54 tw0 ()
55 : time_watcher (this, &tw0::cb)
56 { }}
57tw0;
33 58
34tstamp NOW; 59tstamp NOW;
35 60static bool iom_valid;
36io_manager iom; 61io_manager iom;
37 62
38void time_watcher::set (tstamp when) 63template<class watcher>
64void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
39{ 65{
40 at = when; 66 if (!iom_valid)
67 abort ();
41 68
42 if (registered) 69 if (!w->active)
43 iom.reschedule_time_watchers (); 70 {
44 else 71#if IOM_CHECK
45 iom.reg (this); 72 queue.activity = true;
73#endif
74 queue.push_back (w);
75 w->active = queue.size ();
76 }
46} 77}
47 78
79template<class watcher>
80void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
81{
82 if (!iom_valid)
83 return;
84
85 if (w->active)
86 {
87 queue [w->active - 1] = 0;
88 w->active = 0;
89 }
90}
91
92#if IOM_TIME
48void time_watcher::trigger () 93void time_watcher::trigger ()
49{ 94{
50 call (at); 95 call (*this);
51 96
52 if (registered)
53 iom.reschedule_time_watchers ();
54 else
55 iom.reg (this); 97 iom.reg (this);
56} 98}
57 99
58void time_watcher::start () 100void io_manager::reg (time_watcher *w) { reg (w, tw); }
59{ 101void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
60 if (!registered) 102#endif
61 iom.reg (this);
62}
63 103
64void io_manager::reg (int fd, short events, io_watcher *w) 104#if IOM_IO
65{ 105void io_manager::reg (io_watcher *w) { reg (w, iow); }
66 pollfd pfd;
67
68 pfd.fd = fd;
69 pfd.events = events;
70
71 pfs.push_back (pfd);
72 iow.push_back (w);
73}
74
75void io_manager::unreg (io_watcher *w) 106void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
76{ 107#endif
77 unsigned int sz = iow.size ();
78 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
79 108
80 if (i != sz) 109#if IOM_CHECK
110void io_manager::reg (check_watcher *w) { reg (w, cw); }
111void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
112#endif
113
114#if IOM_IDLE
115void io_manager::reg (idle_watcher *w) { reg (w, iw); }
116void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
117#endif
118
119#if IOM_TIME
120inline void set_now (void)
121{
122 struct timeval tv;
123
124 gettimeofday (&tv, 0);
125
126 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
127#endif
128}
129
130void io_manager::loop ()
131{
132#if IOM_TIME
133 set_now ();
134#endif
135
136 for (;;)
81 { 137 {
82 if (sz == 1) 138 struct timeval *to = 0;
83 { 139 struct timeval tval;
84 pfs.clear (); 140
85 iow.clear (); 141#if IOM_IDLE
142 if (iw.size ())
86 } 143 {
87 else if (i == sz - 1) 144 tval.tv_sec = 0;
88 { 145 tval.tv_usec = 0;
89 iow.pop_back (); 146 to = &tval;
90 pfs.pop_back ();
91 } 147 }
92 else 148 else
149#endif
150
151 {
152#if IOM_TIME
153 time_watcher *next;
154
155 for (;;)
156 {
157 next = tw[0]; // the first time-watcher must exist at ALL times
158
159 for (int i = tw.size (); i--; )
160 if (!tw[i])
161 tw.erase_unordered (i);
162 else if (tw[i]->at < next->at)
163 next = tw[i];
164
165 if (next->at > NOW)
166 {
167 if (next != tw[0])
168 {
169 double diff = next->at - NOW;
170 tval.tv_sec = (int)diff;
171 tval.tv_usec = (int) ((diff - tval.tv_sec) * 1000000);
172 to = &tval;
173 }
174 break;
175 }
176 else
177 {
178 unreg (next);
179 next->call (*next);
180 }
181 }
182#endif
183
184 }
185
186#if IOM_CHECK
187 tw.activity = false;
188
189 for (int i = cw.size (); i--; )
190 if (!cw[i])
191 cw.erase_unordered (i);
192 else
193 cw[i]->call (*cw[i]);
194
195 if (tw.activity)
196 {
197 tval.tv_sec = 0;
198 tval.tv_usec = 0;
199 to = &tval;
200 }
201#endif
202
203#if IOM_IO
204 fd_set rfd, wfd;
205
206 FD_ZERO (&rfd);
207 FD_ZERO (&wfd);
208
209 int fds = 0;
210
211 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
212 if (*i)
93 { 213 {
94 iow[i] = iow[sz - 1]; iow.pop_back (); 214 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
95 pfs[i] = pfs[sz - 1]; pfs.pop_back (); 215 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
216
217 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
96 } 218 }
97 }
98}
99 219
100void io_manager::reschedule_time_watchers () 220 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
101{ 221 break; // no events
102 make_heap (tw.begin (), tw.end (), lowest_first);
103}
104 222
105void io_manager::reg (time_watcher *w) 223 fds = select (fds, &rfd, &wfd, NULL, to);
106{ 224# if IOM_TIME
107 if (w->registered) 225 set_now ();
108 slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher"); 226# endif
109 227
110 w->registered = true; 228 if (fds > 0)
111 229 for (int i = iow.size (); i--; )
112 tw.push_back (w); 230 if (!iow[i])
113 push_heap (tw.begin (), tw.end (), lowest_first); 231 iow.erase_unordered (i);
114} 232 else
115
116void io_manager::unreg (time_watcher *w)
117{
118 if (w->registered)
119 {
120 unsigned int sz = tw.size ();
121 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
122
123 if (i != sz)
124 { 233 {
125 if (i != sz - 1) 234 short revents = iow[i]->events;
126 tw[i] = tw[sz - 1];
127 235
128 tw.pop_back (); 236 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
129 reschedule_time_watchers (); 237 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
238
239 if (revents)
240 iow[i]->call (*iow[i], revents);
241 }
242 else if (fds < 0 && errno != EINTR)
130 } 243 {
244 perror ("Error while waiting for I/O or time event");
245 abort ();
246 }
247#if IOM_IDLE
248 else
249 for (int i = iw.size (); i--; )
250 if (!iw[i])
251 iw.erase_unordered (i);
252 else
253 iw[i]->call (*iw[i]);
254#endif
131 255
132 w->registered = false; 256#elif IOM_TIME
133 } 257 if (!to)
134} 258 break;
135 259
136inline void set_now (void) 260 select (0, 0, 0, 0, &to);
137{ 261 set_now ();
138 struct timeval tv; 262#else
263 break;
264#endif
139 265
140 gettimeofday (&tv, 0); 266 }
141
142 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
143} 267}
144 268
145void io_manager::loop () 269io_manager::io_manager ()
146{ 270{
271 iom_valid = true;
272
273#if IOM_TIME
147 set_now (); 274 set_now ();
148 275
149 for (;;) 276 tw0.start (TSTAMP_MAX);
150 { 277#endif
151 while (tw[0]->at <= NOW)
152 {
153 // remove the first watcher
154 time_watcher *w = tw[0];
155
156 pop_heap (tw.begin (), tw.end (), lowest_first);
157 tw.pop_back ();
158
159 w->registered = false;
160
161 // call it
162 w->call (w->at);
163
164 // re-add it if necessary
165 if (w->at >= 0 && !w->registered)
166 reg (w);
167 }
168
169 int timeout = (int) ((tw[0]->at - NOW) * 1000);
170
171 int fds = poll (&pfs[0], pfs.size (), timeout);
172
173 set_now ();
174
175 for (unsigned int i = 0; fds > 0 && i < iow.size (); ++i)
176 if (pfs[i].revents)
177 {
178 --fds;
179 iow[i]->call (pfs[i].fd, pfs[i].revents);
180 }
181 }
182}
183
184void io_manager::idle_cb (tstamp &ts)
185{
186 ts = NOW + 86400; // wake up every day, for no good reason
187}
188
189io_manager::io_manager ()
190{
191 set_now ();
192 idle = new time_watcher (this, &io_manager::idle_cb);
193 idle->start (0);
194} 278}
195 279
196io_manager::~io_manager () 280io_manager::~io_manager ()
197{ 281{
198 // 282 iom_valid = false;
199} 283}
200 284

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