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Comparing gvpe/src/iom.C (file contents):
Revision 1.11 by pcg, Sat Apr 5 02:32:40 2003 UTC vs.
Revision 1.16 by pcg, Sat Jan 17 16:49:01 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 "gettext.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>
27 34
28#include "slog.h"
29#include "iom.h" 35#include "iom.h"
30 36
37// TSTAMP_MAX must still fit into a positive struct timeval
38#define TSTAMP_MAX (double)(1UL<<31)
39
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 void cb (time_watcher &w)
46 {
47 // should never get called
48 // reached end-of-time, or tstamp has a bogus definition,
49 // or compiler initilization order broken, or somethine else :)
50 abort ();
51 }
52
53 tw0()
54 : time_watcher (this, &tw0::cb)
55 { }
56} tw0;
57
31tstamp NOW; 58tstamp NOW;
32bool iom_valid; 59static bool iom_valid;
33io_manager iom; 60io_manager iom;
34 61
35inline bool earliest_first (const time_watcher *a, const time_watcher *b) 62template<class watcher>
63void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
36{ 64{
37 return a->at > b->at; 65 if (!iom_valid)
38} 66 abort ();
39 67
40void time_watcher::set (tstamp when) 68 if (!w->active)
41{ 69 {
42 at = when; 70 queue.push_back (w);
43 71 w->active = queue.size ();
44 if (registered) 72 }
45 iom.reschedule_time_watchers ();
46} 73}
47 74
75template<class watcher>
76void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
77{
78 if (!iom_valid)
79 return;
80
81 if (w->active)
82 {
83 queue [w->active - 1] = 0;
84 w->active = 0;
85 }
86}
87
88#if IOM_TIME
48void time_watcher::trigger () 89void time_watcher::trigger ()
49{ 90{
50 call (*this); 91 call (*this);
51 92
52 if (registered)
53 iom.reschedule_time_watchers ();
54 else
55 iom.reg (this); 93 iom.reg (this);
56} 94}
57 95
58time_watcher::~time_watcher () 96void io_manager::reg (time_watcher *w) { reg (w, tw); }
59{ 97void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
60 if (iom_valid) 98#endif
61 iom.unreg (this);
62}
63 99
64void io_watcher::set(int fd_, short events_) 100#if IOM_IO
65{ 101void io_manager::reg (io_watcher *w) { reg (w, iow); }
66 fd = fd_; 102void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
67 events = events_; 103#endif
68 104
69 if (registered) 105#if IOM_CHECK
106void io_manager::reg (check_watcher *w) { reg (w, cw); }
107void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
108#endif
109
110#if IOM_IDLE
111void io_manager::reg (idle_watcher *w) { reg (w, iw); }
112void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
113#endif
114
115#if IOM_TIME
116inline void set_now (void)
117{
118 struct timeval tv;
119
120 gettimeofday (&tv, 0);
121
122 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
123#endif
124}
125
126void io_manager::loop ()
127{
128#if IOM_TIME
129 set_now ();
130#endif
131
132 for (;;)
70 { 133 {
71 iom.unreg (this); 134 struct timeval *to = 0;
72 iom.reg (this); 135 struct timeval tval;
73 }
74}
75 136
76io_watcher::~io_watcher () 137#if IOM_IDLE
77{ 138 if (iw.size ())
78 if (iom_valid)
79 iom.unreg (this);
80}
81
82void io_manager::reg (io_watcher *w)
83{
84 if (!w->registered)
85 {
86 w->registered = true;
87
88 pollfd pfd;
89
90 pfd.fd = w->fd;
91 pfd.events = w->events;
92
93 pfs.push_back (pfd);
94 iow.push_back (w);
95 }
96}
97
98void io_manager::unreg (io_watcher *w)
99{
100 if (w->registered)
101 {
102 w->registered = false;
103
104 unsigned int sz = iow.size ();
105 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
106
107 assert (i != sz);
108
109 if (sz == 1)
110 { 139 {
111 pfs.clear (); 140 tval.tv_sec = 0;
112 iow.clear (); 141 tval.tv_usec = 0;
113 } 142 to = &tval;
114 else if (i == sz - 1)
115 {
116 iow.pop_back ();
117 pfs.pop_back ();
118 } 143 }
119 else 144 else
145#endif
120 { 146 {
121 iow[i] = iow[sz - 1]; iow.pop_back (); 147#if IOM_TIME
122 pfs[i] = pfs[sz - 1]; pfs.pop_back (); 148 time_watcher *next;
149
150 for (;;)
151 {
152 next = tw[0]; // the first time-watcher must exist at ALL times
153
154 for (int i = tw.size (); i--; )
155 if (!tw[i])
156 tw.erase_unordered (i);
157 else if (tw[i]->at < next->at)
158 next = tw[i];
159
160 if (next->at > NOW)
161 {
162 if (next != tw[0])
163 {
164 double diff = next->at - NOW;
165 tval.tv_sec = (int)diff;
166 tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
167 to = &tval;
168 }
169 break;
170 }
171 else
172 {
173 unreg (next);
174 next->call (*next);
175 }
176 }
177#endif
123 } 178 }
179
180#if IOM_CHECK
181 for (int i = cw.size (); i--; )
182 if (!cw[i])
183 cw.erase_unordered (i);
184 else
185 cw[i]->call (*cw[i]);
186#endif
187
188#if IOM_IO
189 fd_set rfd, wfd, efd;
190
191 FD_ZERO (&rfd);
192 FD_ZERO (&wfd);
193
194 int fds = 0;
195
196 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
197 if (*i)
198 {
199 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
200 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
201
202 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
203 }
204
205 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
206 break; // no events
207
208 fds = select (fds, &rfd, &wfd, &efd, to);
209# if IOM_TIME
210 set_now ();
211# endif
212
213 if (fds > 0)
214 for (int i = iow.size (); i--; )
215 if (!iow[i])
216 iow.erase_unordered (i);
217 else
218 {
219 short revents = iow[i]->events;
220
221 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
222 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
223
224 if (revents)
225 iow[i]->call (*iow[i], revents);
226 }
227 else if (fds < 0 && errno != EINTR)
228 {
229 perror ("Error while waiting for I/O or time event");
230 abort ();
231 }
232#if IOM_IDLE
233 else
234 for (int i = iw.size (); i--; )
235 if (!iw[i])
236 iw.erase_unordered (i);
237 else
238 iw[i]->call (*iw[i]);
239#endif
240
241#elif IOM_TIME
242 if (!to)
243 break;
244
245 select (0, 0, 0, 0, &to);
246 set_now ();
247#else
248 break;
249#endif
124 } 250 }
125} 251}
126 252
127void io_manager::reschedule_time_watchers () 253io_manager::io_manager ()
128{ 254{
129 make_heap (tw.begin (), tw.end (), earliest_first); 255 iom_valid = true;
130}
131 256
132void io_manager::reg (time_watcher *w) 257#if IOM_TIME
133{
134 if (!w->registered)
135 {
136 w->registered = true;
137
138 tw.push_back (w);
139 push_heap (tw.begin (), tw.end (), earliest_first);
140 }
141}
142
143void io_manager::unreg (time_watcher *w)
144{
145 if (w->registered)
146 {
147 w->registered = false;
148
149 unsigned int sz = tw.size ();
150 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
151
152 assert (i != sz);
153
154 if (i != sz - 1)
155 tw[i] = tw[sz - 1];
156
157 tw.pop_back ();
158 reschedule_time_watchers ();
159 }
160}
161
162inline void set_now (void)
163{
164 struct timeval tv;
165
166 gettimeofday (&tv, 0);
167
168 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
169}
170
171void io_manager::loop ()
172{
173 set_now (); 258 set_now ();
174 259
175 for (;;) 260 tw0.start (TSTAMP_MAX);
176 { 261#endif
177 while (tw[0]->at <= NOW)
178 {
179 // remove the first watcher
180 time_watcher *w = tw[0];
181
182 pop_heap (tw.begin (), tw.end (), earliest_first);
183 tw.pop_back ();
184
185 w->registered = false;
186
187 // call it
188 w->call (*w);
189
190 // re-add it if necessary
191 if (w->at >= 0 && !w->registered)
192 reg (w);
193 }
194
195 int timeout = (int) ((tw[0]->at - NOW) * 1000);
196
197 int fds = poll (&pfs[0], pfs.size (), timeout);
198
199 set_now ();
200
201 vector<io_watcher *>::iterator w;
202 vector<pollfd>::iterator p;
203
204 for (w = iow.begin (), p = pfs.begin ();
205 fds > 0 && w < iow.end ();
206 ++w, ++p)
207 if (p->revents)
208 {
209 --fds;
210
211 if (p->revents & POLLNVAL)
212 {
213 slog (L_ERR, _("io_watcher started on illegal file descriptor, disabling."));
214 (*w)->stop ();
215 }
216 else
217 (*w)->call (**w, p->revents);
218 }
219 }
220}
221
222void io_manager::idle_cb (time_watcher &w)
223{
224 w.at = NOW + 86400; // wake up every day, for no good reason
225}
226
227io_manager::io_manager ()
228{
229 iom_valid = true;
230
231 set_now ();
232 idle = new time_watcher (this, &io_manager::idle_cb);
233 idle->start (0);
234} 262}
235 263
236io_manager::~io_manager () 264io_manager::~io_manager ()
237{ 265{
238 iom_valid = false; 266 iom_valid = false;

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