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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 1.17 by pcg, Thu Jan 29 23:17:39 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#if IOM_CHECK
43 71 queue.activity = true;
44 if (registered) 72#endif
45 iom.reschedule_time_watchers (); 73 queue.push_back (w);
74 w->active = queue.size ();
75 }
46} 76}
47 77
78template<class watcher>
79void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
80{
81 if (!iom_valid)
82 return;
83
84 if (w->active)
85 {
86 queue [w->active - 1] = 0;
87 w->active = 0;
88 }
89}
90
91#if IOM_TIME
48void time_watcher::trigger () 92void time_watcher::trigger ()
49{ 93{
50 call (*this); 94 call (*this);
51 95
52 if (registered)
53 iom.reschedule_time_watchers ();
54 else
55 iom.reg (this); 96 iom.reg (this);
56} 97}
57 98
58time_watcher::~time_watcher ()
59{
60 if (iom_valid)
61 iom.unreg (this);
62}
63
64void io_watcher::set(int fd_, short events_)
65{
66 fd = fd_;
67 events = events_;
68
69 if (registered)
70 {
71 iom.unreg (this);
72 iom.reg (this);
73 }
74}
75
76io_watcher::~io_watcher ()
77{
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 {
111 pfs.clear ();
112 iow.clear ();
113 }
114 else if (i == sz - 1)
115 {
116 iow.pop_back ();
117 pfs.pop_back ();
118 }
119 else
120 {
121 iow[i] = iow[sz - 1]; iow.pop_back ();
122 pfs[i] = pfs[sz - 1]; pfs.pop_back ();
123 }
124 }
125}
126
127void io_manager::reschedule_time_watchers ()
128{
129 make_heap (tw.begin (), tw.end (), earliest_first);
130}
131
132void io_manager::reg (time_watcher *w) 99void io_manager::reg (time_watcher *w) { reg (w, tw); }
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) 100void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
144{ 101#endif
145 if (w->registered)
146 {
147 w->registered = false;
148 102
149 unsigned int sz = tw.size (); 103#if IOM_IO
150 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin (); 104void io_manager::reg (io_watcher *w) { reg (w, iow); }
105void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
106#endif
151 107
152 assert (i != sz); 108#if IOM_CHECK
153 109void io_manager::reg (check_watcher *w) { reg (w, cw); }
154 if (i != sz - 1) 110void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
155 tw[i] = tw[sz - 1]; 111#endif
156 112
157 tw.pop_back (); 113#if IOM_IDLE
158 reschedule_time_watchers (); 114void io_manager::reg (idle_watcher *w) { reg (w, iw); }
159 } 115void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
160} 116#endif
161 117
118#if IOM_TIME
162inline void set_now (void) 119inline void set_now (void)
163{ 120{
164 struct timeval tv; 121 struct timeval tv;
165 122
166 gettimeofday (&tv, 0); 123 gettimeofday (&tv, 0);
167 124
168 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; 125 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
126#endif
169} 127}
170 128
171void io_manager::loop () 129void io_manager::loop ()
172{ 130{
131#if IOM_TIME
173 set_now (); 132 set_now ();
133#endif
174 134
175 for (;;) 135 for (;;)
176 { 136 {
177 while (tw[0]->at <= NOW) 137 struct timeval *to = 0;
138 struct timeval tval;
139
140#if IOM_IDLE
141 if (iw.size ())
142 {
143 tval.tv_sec = 0;
144 tval.tv_usec = 0;
145 to = &tval;
146 }
147 else
148#endif
149 {
150#if IOM_TIME
151 time_watcher *next;
152
153 for (;;)
154 {
155 next = tw[0]; // the first time-watcher must exist at ALL times
156
157 for (int i = tw.size (); i--; )
158 if (!tw[i])
159 tw.erase_unordered (i);
160 else if (tw[i]->at < next->at)
161 next = tw[i];
162
163 if (next->at > NOW)
164 {
165 if (next != tw[0])
166 {
167 double diff = next->at - NOW;
168 tval.tv_sec = (int)diff;
169 tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
170 to = &tval;
171 }
172 break;
173 }
174 else
175 {
176 unreg (next);
177 next->call (*next);
178 }
179 }
180#endif
181 }
182
183#if IOM_CHECK
184 tw.activity = false;
185
186 for (int i = cw.size (); i--; )
187 if (!cw[i])
188 cw.erase_unordered (i);
189 else
190 cw[i]->call (*cw[i]);
191
192 if (tw.activity)
193 {
194 tval.tv_sec = 0;
195 tval.tv_usec = 0;
196 to = &tval;
197 }
198#endif
199
200#if IOM_IO
201 fd_set rfd, wfd, efd;
202
203 FD_ZERO (&rfd);
204 FD_ZERO (&wfd);
205
206 int fds = 0;
207
208 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
209 if (*i)
178 { 210 {
179 // remove the first watcher 211 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
180 time_watcher *w = tw[0]; 212 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
181 213
182 pop_heap (tw.begin (), tw.end (), earliest_first); 214 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
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 } 215 }
194 216
195 int timeout = (int) ((tw[0]->at - NOW) * 1000); 217 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
218 break; // no events
196 219
197 int fds = poll (&pfs[0], pfs.size (), timeout); 220 fds = select (fds, &rfd, &wfd, &efd, to);
198 221# if IOM_TIME
199 set_now (); 222 set_now ();
223# endif
200 224
201 vector<io_watcher *>::iterator w; 225 if (fds > 0)
202 vector<pollfd>::iterator p; 226 for (int i = iow.size (); i--; )
203 227 if (!iow[i])
204 for (w = iow.begin (), p = pfs.begin (); 228 iow.erase_unordered (i);
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 229 else
230 {
231 short revents = iow[i]->events;
232
233 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
234 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
235
236 if (revents)
217 (*w)->call (**w, p->revents); 237 iow[i]->call (*iow[i], revents);
218 } 238 }
239 else if (fds < 0 && errno != EINTR)
240 {
241 perror ("Error while waiting for I/O or time event");
242 abort ();
243 }
244#if IOM_IDLE
245 else
246 for (int i = iw.size (); i--; )
247 if (!iw[i])
248 iw.erase_unordered (i);
249 else
250 iw[i]->call (*iw[i]);
251#endif
252
253#elif IOM_TIME
254 if (!to)
255 break;
256
257 select (0, 0, 0, 0, &to);
258 set_now ();
259#else
260 break;
261#endif
219 } 262 }
220} 263}
221 264
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 () 265io_manager::io_manager ()
228{ 266{
229 iom_valid = true; 267 iom_valid = true;
230 268
269#if IOM_TIME
231 set_now (); 270 set_now ();
232 idle = new time_watcher (this, &io_manager::idle_cb); 271
233 idle->start (0); 272 tw0.start (TSTAMP_MAX);
273#endif
234} 274}
235 275
236io_manager::~io_manager () 276io_manager::~io_manager ()
237{ 277{
238 iom_valid = false; 278 iom_valid = false;

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