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Comparing gvpe/src/iom.C (file contents):
Revision 1.9 by pcg, Wed Apr 2 21:02:25 2003 UTC vs.
Revision 1.13 by pcg, Sat Jan 17 01:18:36 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
24#include <sys/select.h>
21#include <sys/time.h> 25#include <sys/time.h>
22 26
23#include <algorithm>
24#include <functional>
25
26#include "slog.h"
27#include "iom.h" 27#include "iom.h"
28 28
29inline bool earliest_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;
32}
33 31
34tstamp NOW; 32tstamp NOW;
35 33static bool iom_valid;
36io_manager iom; 34io_manager iom;
37 35
38void time_watcher::set (tstamp when) 36template<class watcher>
37void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
39{ 38{
40 at = when; 39 if (!iom_valid)
40 abort ();
41 41
42 if (registered) 42 if (!w->active)
43 iom.reschedule_time_watchers (); 43 {
44 else 44 queue.push_back (w);
45 iom.reg (this); 45 w->active = queue.size ();
46 }
46} 47}
47 48
49template<class watcher>
50void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
51{
52 if (!iom_valid)
53 return;
54
55 if (w->active)
56 {
57 queue [w->active - 1] = 0;
58 w->active = 0;
59 }
60}
61
62#if IOM_TIME
48void time_watcher::trigger () 63void time_watcher::trigger ()
49{ 64{
50 call (*this); 65 call (*this);
51 66
52 if (registered)
53 iom.reschedule_time_watchers ();
54 else
55 iom.reg (this); 67 iom.reg (this);
56} 68}
57 69
58void time_watcher::start () 70void io_manager::reg (time_watcher *w) { reg (w, tw); }
59{ 71void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
60 if (!registered) 72#endif
61 iom.reg (this);
62}
63 73
74#if IOM_IO
64void io_manager::reg (io_watcher *w) 75void io_manager::reg (io_watcher *w) { reg (w, iow); }
65{
66 pollfd pfd;
67
68 pfd.fd = w->fd;
69 pfd.events = w->events;
70
71 pfs.push_back (pfd);
72 iow.push_back (w);
73}
74
75void io_manager::unreg (io_watcher *w) 76void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
76{ 77#endif
77 unsigned int sz = iow.size ();
78 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
79 78
80 if (i != sz) 79#if IOM_CHECK
80void io_manager::reg (check_watcher *w) { reg (w, cw); }
81void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
82#endif
83
84#if IOM_IDLE
85void io_manager::reg (idle_watcher *w) { reg (w, iw); }
86void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
87#endif
88
89#if IOM_TIME
90inline void set_now (void)
91{
92 struct timeval tv;
93
94 gettimeofday (&tv, 0);
95
96 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
97#endif
98}
99
100void io_manager::loop ()
101{
102#if IOM_TIME
103 set_now ();
104#endif
105
106 for (;;)
81 { 107 {
82 if (sz == 1) 108 struct timeval *to = 0;
109 struct timeval tval;
110
111#if IOM_IDLE
112 if (iw.size ())
83 { 113 {
84 pfs.clear (); 114 tval.tv_sec = 0;
85 iow.clear (); 115 tval.tv_usec = 0;
86 } 116 to = &tval;
87 else if (i == sz - 1)
88 {
89 iow.pop_back ();
90 pfs.pop_back ();
91 } 117 }
92 else 118 else
119#endif
93 { 120 {
94 iow[i] = iow[sz - 1]; iow.pop_back (); 121#if IOM_TIME
95 pfs[i] = pfs[sz - 1]; pfs.pop_back (); 122 time_watcher *next;
123
124 for (;;)
125 {
126 next = tw[0]; // the first time-watcher must exist at ALL times
127
128 for (int i = tw.size (); i--; )
129 if (!tw[i])
130 tw.erase_unordered (i);
131 else if (tw[i]->at < next->at)
132 next = tw[i];
133
134 if (next->at > NOW)
135 {
136 if (next != tw[0])
137 {
138 double diff = next->at - NOW;
139 tval.tv_sec = (int)diff;
140 tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
141 to = &tval;
142 }
143 break;
144 }
145 else
146 {
147 unreg (next);
148 next->call (*next);
149 }
150 }
151#endif
96 } 152 }
153
154#if IOM_CHECK
155 for (int i = cw.size (); i--; )
156 if (!cw[i])
157 cw.erase_unordered (i);
158 else
159 cw[i]->call (*cw[i]);
160#endif
161
162#if IOM_IO
163 fd_set rfd, wfd, efd;
164
165 FD_ZERO (&rfd);
166 FD_ZERO (&wfd);
167
168 int fds = 0;
169
170 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
171 if (*i)
172 {
173 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
174 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
175
176 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
177 }
178
179 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
180 break; // no events
181
182 fds = select (fds, &rfd, &wfd, &efd, to);
183# if IOM_TIME
184 set_now ();
185# endif
186
187 if (fds > 0)
188 for (int i = iow.size (); i--; )
189 if (!iow[i])
190 iow.erase_unordered (i);
191 else
192 {
193 short revents = iow[i]->events;
194
195 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
196 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
197
198 if (revents)
199 iow[i]->call (*iow[i], revents);
200 }
201 else if (fds < 0 && errno != EINTR)
202 {
203 perror ("Error while waiting for I/O or time event");
204 abort ();
205 }
206#if IOM_IDLE
207 else
208 for (int i = iw.size (); i--; )
209 if (!iw[i])
210 iw.erase_unordered (i);
211 else
212 iw[i]->call (*iw[i]);
213#endif
214
215#elif IOM_TIME
216 if (!to)
217 break;
218
219 select (0, 0, 0, 0, &to);
220 set_now ();
221#else
222 break;
223#endif
97 } 224 }
98} 225}
99 226
100void io_manager::reschedule_time_watchers () 227// this is a dummy time watcher to ensure that the first
101{ 228// time watcher is _always_ valid, this gets rid of a lot
102 make_heap (tw.begin (), tw.end (), earliest_first); 229// of null-pointer-checks
103} 230static struct tw0 : time_watcher {
104 231 void cb (time_watcher &w)
105void io_manager::reg (time_watcher *w)
106{
107 if (w->registered)
108 slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher");
109
110 w->registered = true;
111
112 tw.push_back (w);
113 push_heap (tw.begin (), tw.end (), earliest_first);
114}
115
116void io_manager::unreg (time_watcher *w)
117{
118 if (w->registered)
119 { 232 {
120 unsigned int sz = tw.size (); 233 // should never get called
121 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin (); 234 // reached end-of-time, or tstamp has a bogus definition :)
235 abort ();
236 }
122 237
123 if (i != sz) 238 tw0()
124 { 239 : time_watcher (this, &tw0::cb)
125 if (i != sz - 1)
126 tw[i] = tw[sz - 1];
127
128 tw.pop_back ();
129 reschedule_time_watchers ();
130 }
131
132 w->registered = false;
133 } 240 { }
134} 241} tw0;
135 242
136inline void set_now (void) 243io_manager::io_manager ()
137{ 244{
138 struct timeval tv; 245 iom_valid = true;
139 246
140 gettimeofday (&tv, 0); 247#if IOM_TIME
141
142 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
143}
144
145void io_manager::loop ()
146{
147 set_now (); 248 set_now ();
148 249
149 for (;;) 250 tw0.start (TSTAMP_MAX);
150 { 251#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 (), earliest_first);
157 tw.pop_back ();
158
159 w->registered = false;
160
161 // call it
162 w->call (*w);
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 vector<io_watcher *>::iterator w;
176 vector<pollfd>::iterator p;
177
178 for (w = iow.begin (), p = pfs.begin ();
179 fds > 0 && w < iow.end ();
180 ++w, ++p)
181 if (p->revents)
182 {
183 --fds;
184 (*w)->call (**w, p->revents);
185 }
186 }
187}
188
189void io_manager::idle_cb (time_watcher &w)
190{
191 w.at = NOW + 86400; // wake up every day, for no good reason
192}
193
194io_manager::io_manager ()
195{
196 set_now ();
197 idle = new time_watcher (this, &io_manager::idle_cb);
198 idle->start (0);
199} 252}
200 253
201io_manager::~io_manager () 254io_manager::~io_manager ()
202{ 255{
203 // 256 iom_valid = false;
204} 257}
205 258

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