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Comparing gvpe/src/iom.C (file contents):
Revision 1.12 by pcg, Thu Oct 16 02:41:21 2003 UTC vs.
Revision 1.16 by pcg, Sat Jan 17 16:49:01 2004 UTC

1/* 1/*
2 iom.C -- generic I/O multiplexor 2 iom.C -- generic I/O multiplexor
3 Copyright (C) 2003 Marc Lehmann <pcg@goof.com> 3 Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com>
4 4
5 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
6 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
7 the Free Software Foundation; either version 2 of the License, or 7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version. 8 (at your option) any later version.
… …
15 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
16 along with this program; if not, write to the Free Software 16 along with this program; if not, write to the Free Software
17 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
18*/ 18*/
19 19
20#include "config.h" 20#include <cstdio>
21#include <cstdlib>
22#include <cerrno>
21 23
22#include <sys/time.h> 24#include <sys/time.h>
23 25
24#include <algorithm> 26#if 1 // older unices need these includes for select(2)
25#include <functional> 27# include <unistd.h>
28# include <sys/types.h>
29#endif
26 30
27#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>
28 34
29#include "slog.h"
30#include "iom.h" 35#include "iom.h"
31 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
32tstamp NOW; 58tstamp NOW;
33bool iom_valid; 59static bool iom_valid;
34io_manager iom; 60io_manager iom;
35 61
36inline 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)
37{ 64{
38 return a->at > b->at; 65 if (!iom_valid)
39} 66 abort ();
40 67
41void time_watcher::set (tstamp when) 68 if (!w->active)
42{ 69 {
43 at = when; 70 queue.push_back (w);
44 71 w->active = queue.size ();
45 if (registered) 72 }
46 iom.reschedule_time_watchers ();
47} 73}
48 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
49void time_watcher::trigger () 89void time_watcher::trigger ()
50{ 90{
51 call (*this); 91 call (*this);
52 92
53 if (registered)
54 iom.reschedule_time_watchers ();
55 else
56 iom.reg (this); 93 iom.reg (this);
57} 94}
58 95
59time_watcher::~time_watcher () 96void io_manager::reg (time_watcher *w) { reg (w, tw); }
60{ 97void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
61 if (iom_valid) 98#endif
62 iom.unreg (this);
63}
64 99
65void io_watcher::set(int fd_, short events_) 100#if IOM_IO
66{ 101void io_manager::reg (io_watcher *w) { reg (w, iow); }
67 fd = fd_; 102void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
68 events = events_; 103#endif
69 104
70 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 (;;)
71 { 133 {
72 iom.unreg (this); 134 struct timeval *to = 0;
73 iom.reg (this); 135 struct timeval tval;
74 }
75}
76 136
77io_watcher::~io_watcher () 137#if IOM_IDLE
78{ 138 if (iw.size ())
79 if (iom_valid)
80 iom.unreg (this);
81}
82
83void io_manager::reg (io_watcher *w)
84{
85 if (!w->registered)
86 {
87 w->registered = true;
88
89 pollfd pfd;
90
91 pfd.fd = w->fd;
92 pfd.events = w->events;
93
94 pfs.push_back (pfd);
95 iow.push_back (w);
96 }
97}
98
99void io_manager::unreg (io_watcher *w)
100{
101 if (w->registered)
102 {
103 w->registered = false;
104
105 unsigned int sz = iow.size ();
106 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
107
108 assert (i != sz);
109
110 if (sz == 1)
111 { 139 {
112 pfs.clear (); 140 tval.tv_sec = 0;
113 iow.clear (); 141 tval.tv_usec = 0;
114 } 142 to = &tval;
115 else if (i == sz - 1)
116 {
117 iow.pop_back ();
118 pfs.pop_back ();
119 } 143 }
120 else 144 else
145#endif
121 { 146 {
122 iow[i] = iow[sz - 1]; iow.pop_back (); 147#if IOM_TIME
123 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
124 } 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
125 } 250 }
126} 251}
127 252
128void io_manager::reschedule_time_watchers () 253io_manager::io_manager ()
129{ 254{
130 make_heap (tw.begin (), tw.end (), earliest_first); 255 iom_valid = true;
131}
132 256
133void io_manager::reg (time_watcher *w) 257#if IOM_TIME
134{
135 if (!w->registered)
136 {
137 w->registered = true;
138
139 tw.push_back (w);
140 push_heap (tw.begin (), tw.end (), earliest_first);
141 }
142}
143
144void io_manager::unreg (time_watcher *w)
145{
146 if (w->registered)
147 {
148 w->registered = false;
149
150 unsigned int sz = tw.size ();
151 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
152
153 assert (i != sz);
154
155 if (i != sz - 1)
156 tw[i] = tw[sz - 1];
157
158 tw.pop_back ();
159 reschedule_time_watchers ();
160 }
161}
162
163inline void set_now (void)
164{
165 struct timeval tv;
166
167 gettimeofday (&tv, 0);
168
169 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
170}
171
172void io_manager::loop ()
173{
174 set_now (); 258 set_now ();
175 259
176 for (;;) 260 tw0.start (TSTAMP_MAX);
177 { 261#endif
178 while (tw[0]->at <= NOW)
179 {
180 // remove the first watcher
181 time_watcher *w = tw[0];
182
183 pop_heap (tw.begin (), tw.end (), earliest_first);
184 tw.pop_back ();
185
186 w->registered = false;
187
188 // call it
189 w->call (*w);
190
191 // re-add it if necessary
192 if (w->at >= 0 && !w->registered)
193 reg (w);
194 }
195
196 int timeout = (int) ((tw[0]->at - NOW) * 1000);
197
198 int fds = poll (&pfs[0], pfs.size (), timeout);
199
200 set_now ();
201
202 vector<io_watcher *>::iterator w;
203 vector<pollfd>::iterator p;
204
205 for (w = iow.begin (), p = pfs.begin ();
206 fds > 0 && w < iow.end ();
207 ++w, ++p)
208 if (p->revents)
209 {
210 --fds;
211
212 if (p->revents & POLLNVAL)
213 {
214 slog (L_ERR, _("io_watcher started on illegal file descriptor, disabling."));
215 (*w)->stop ();
216 }
217 else
218 (*w)->call (**w, p->revents);
219 }
220 }
221}
222
223void io_manager::idle_cb (time_watcher &w)
224{
225 w.at = NOW + 86400; // wake up every day, for no good reason
226}
227
228io_manager::io_manager ()
229{
230 iom_valid = true;
231
232 set_now ();
233 idle = new time_watcher (this, &io_manager::idle_cb);
234 idle->start (0);
235} 262}
236 263
237io_manager::~io_manager () 264io_manager::~io_manager ()
238{ 265{
239 iom_valid = false; 266 iom_valid = false;

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