ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/gvpe/src/iom.C
(Generate patch)

Comparing gvpe/src/iom.C (file contents):
Revision 1.10 by pcg, Fri Apr 4 05:26:45 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
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 {
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;
58
29tstamp NOW; 59tstamp NOW;
30bool iom_valid; 60static bool iom_valid;
31io_manager iom; 61io_manager iom;
32 62
33inline bool earliest_first (const time_watcher *a, const time_watcher *b) 63template<class watcher>
64void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
34{ 65{
35 return a->at > b->at; 66 if (!iom_valid)
36} 67 abort ();
37 68
38void time_watcher::set (tstamp when) 69 if (!w->active)
39{ 70 {
40 at = when; 71#if IOM_CHECK
41 72 queue.activity = true;
42 if (registered) 73#endif
43 iom.reschedule_time_watchers (); 74 queue.push_back (w);
44 else 75 w->active = queue.size ();
45 iom.reg (this); 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 (*this); 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
64time_watcher::~time_watcher () 104#if IOM_IO
65{
66 if (iom_valid)
67 iom.unreg (this);
68}
69
70io_watcher::~io_watcher ()
71{
72 if (iom_valid)
73 iom.unreg (this);
74}
75
76void io_manager::reg (io_watcher *w) 105void io_manager::reg (io_watcher *w) { reg (w, iow); }
77{
78 pollfd pfd;
79
80 pfs.push_back (pfd);
81 iow.push_back (w);
82
83 w->p = &(*(pfs.end () - 1));
84}
85
86void io_manager::unreg (io_watcher *w) 106void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
87{ 107#endif
88 if (w->p)
89 {
90 unsigned int sz = iow.size ();
91 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
92 108
93 assert (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
94 113
95 if (sz == 1) 114#if IOM_IDLE
96 { 115void io_manager::reg (idle_watcher *w) { reg (w, iw); }
97 pfs.clear (); 116void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
98 iow.clear (); 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 (;;)
137 {
138 struct timeval *to = 0;
139 struct timeval tval;
140
141#if IOM_IDLE
142 if (iw.size ())
99 } 143 {
100 else if (i == sz - 1) 144 tval.tv_sec = 0;
101 { 145 tval.tv_usec = 0;
102 iow.pop_back (); 146 to = &tval;
103 pfs.pop_back ();
104 } 147 }
105 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)
106 { 213 {
107 iow[i] = iow[sz - 1]; iow.pop_back (); 214 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
108 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;
109 } 218 }
110 219
111 w->p = 0; 220 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
112 } 221 break; // no events
113}
114 222
115void io_manager::reschedule_time_watchers () 223 fds = select (fds, &rfd, &wfd, NULL, to);
116{ 224# if IOM_TIME
117 make_heap (tw.begin (), tw.end (), earliest_first); 225 set_now ();
118} 226# endif
119 227
120void io_manager::reg (time_watcher *w) 228 if (fds > 0)
121{ 229 for (int i = iow.size (); i--; )
122 w->registered = true; 230 if (!iow[i])
231 iow.erase_unordered (i);
232 else
233 {
234 short revents = iow[i]->events;
123 235
124 tw.push_back (w); 236 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
125 push_heap (tw.begin (), tw.end (), earliest_first); 237 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
126}
127 238
128void io_manager::unreg (time_watcher *w) 239 if (revents)
129{ 240 iow[i]->call (*iow[i], revents);
130 if (w->registered) 241 }
131 { 242 else if (fds < 0 && errno != EINTR)
132 unsigned int sz = tw.size ();
133 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
134
135 assert (i != sz);
136 243 {
137 if (i != sz - 1) 244 perror ("Error while waiting for I/O or time event");
138 tw[i] = tw[sz - 1]; 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
139 255
140 tw.pop_back (); 256#elif IOM_TIME
141 reschedule_time_watchers (); 257 if (!to)
258 break;
142 259
143 w->registered = false; 260 select (0, 0, 0, 0, &to);
144 } 261 set_now ();
145} 262#else
263 break;
264#endif
146 265
147inline void set_now (void) 266 }
148{
149 struct timeval tv;
150
151 gettimeofday (&tv, 0);
152
153 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
154} 267}
155 268
156void io_manager::loop () 269io_manager::io_manager ()
157{ 270{
271 iom_valid = true;
272
273#if IOM_TIME
158 set_now (); 274 set_now ();
159 275
160 for (;;) 276 tw0.start (TSTAMP_MAX);
161 { 277#endif
162 while (tw[0]->at <= NOW)
163 {
164 // remove the first watcher
165 time_watcher *w = tw[0];
166
167 pop_heap (tw.begin (), tw.end (), earliest_first);
168 tw.pop_back ();
169
170 w->registered = false;
171
172 // call it
173 w->call (*w);
174
175 // re-add it if necessary
176 if (w->at >= 0 && !w->registered)
177 reg (w);
178 }
179
180 int timeout = (int) ((tw[0]->at - NOW) * 1000);
181
182 int fds = poll (&pfs[0], pfs.size (), timeout);
183
184 set_now ();
185
186 vector<io_watcher *>::iterator w;
187 vector<pollfd>::iterator p;
188
189 for (w = iow.begin (), p = pfs.begin ();
190 fds > 0 && w < iow.end ();
191 ++w, ++p)
192 if (p->revents)
193 {
194 --fds;
195 (*w)->call (**w, p->revents);
196 }
197 }
198}
199
200void io_manager::idle_cb (time_watcher &w)
201{
202 w.at = NOW + 86400; // wake up every day, for no good reason
203}
204
205io_manager::io_manager ()
206{
207 iom_valid = true;
208
209 set_now ();
210 idle = new time_watcher (this, &io_manager::idle_cb);
211 idle->start (0);
212} 278}
213 279
214io_manager::~io_manager () 280io_manager::~io_manager ()
215{ 281{
216 iom_valid = false; 282 iom_valid = false;

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines