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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 1.17 by pcg, Thu Jan 29 23:17:39 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#if IOM_CHECK
44 71 queue.activity = true;
45 if (registered) 72#endif
46 iom.reschedule_time_watchers (); 73 queue.push_back (w);
74 w->active = queue.size ();
75 }
47} 76}
48 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
49void time_watcher::trigger () 92void time_watcher::trigger ()
50{ 93{
51 call (*this); 94 call (*this);
52 95
53 if (registered)
54 iom.reschedule_time_watchers ();
55 else
56 iom.reg (this); 96 iom.reg (this);
57} 97}
58 98
59time_watcher::~time_watcher ()
60{
61 if (iom_valid)
62 iom.unreg (this);
63}
64
65void io_watcher::set(int fd_, short events_)
66{
67 fd = fd_;
68 events = events_;
69
70 if (registered)
71 {
72 iom.unreg (this);
73 iom.reg (this);
74 }
75}
76
77io_watcher::~io_watcher ()
78{
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 {
112 pfs.clear ();
113 iow.clear ();
114 }
115 else if (i == sz - 1)
116 {
117 iow.pop_back ();
118 pfs.pop_back ();
119 }
120 else
121 {
122 iow[i] = iow[sz - 1]; iow.pop_back ();
123 pfs[i] = pfs[sz - 1]; pfs.pop_back ();
124 }
125 }
126}
127
128void io_manager::reschedule_time_watchers ()
129{
130 make_heap (tw.begin (), tw.end (), earliest_first);
131}
132
133void io_manager::reg (time_watcher *w) 99void io_manager::reg (time_watcher *w) { reg (w, tw); }
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) 100void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
145{ 101#endif
146 if (w->registered)
147 {
148 w->registered = false;
149 102
150 unsigned int sz = tw.size (); 103#if IOM_IO
151 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
152 107
153 assert (i != sz); 108#if IOM_CHECK
154 109void io_manager::reg (check_watcher *w) { reg (w, cw); }
155 if (i != sz - 1) 110void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
156 tw[i] = tw[sz - 1]; 111#endif
157 112
158 tw.pop_back (); 113#if IOM_IDLE
159 reschedule_time_watchers (); 114void io_manager::reg (idle_watcher *w) { reg (w, iw); }
160 } 115void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
161} 116#endif
162 117
118#if IOM_TIME
163inline void set_now (void) 119inline void set_now (void)
164{ 120{
165 struct timeval tv; 121 struct timeval tv;
166 122
167 gettimeofday (&tv, 0); 123 gettimeofday (&tv, 0);
168 124
169 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; 125 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
126#endif
170} 127}
171 128
172void io_manager::loop () 129void io_manager::loop ()
173{ 130{
131#if IOM_TIME
174 set_now (); 132 set_now ();
133#endif
175 134
176 for (;;) 135 for (;;)
177 { 136 {
178 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)
179 { 210 {
180 // remove the first watcher 211 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
181 time_watcher *w = tw[0]; 212 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
182 213
183 pop_heap (tw.begin (), tw.end (), earliest_first); 214 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
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 } 215 }
195 216
196 int timeout = (int) ((tw[0]->at - NOW) * 1000); 217 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
218 break; // no events
197 219
198 int fds = poll (&pfs[0], pfs.size (), timeout); 220 fds = select (fds, &rfd, &wfd, &efd, to);
199 221# if IOM_TIME
200 set_now (); 222 set_now ();
223# endif
201 224
202 vector<io_watcher *>::iterator w; 225 if (fds > 0)
203 vector<pollfd>::iterator p; 226 for (int i = iow.size (); i--; )
204 227 if (!iow[i])
205 for (w = iow.begin (), p = pfs.begin (); 228 iow.erase_unordered (i);
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 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)
218 (*w)->call (**w, p->revents); 237 iow[i]->call (*iow[i], revents);
219 } 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
220 } 262 }
221} 263}
222 264
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 () 265io_manager::io_manager ()
229{ 266{
230 iom_valid = true; 267 iom_valid = true;
231 268
269#if IOM_TIME
232 set_now (); 270 set_now ();
233 idle = new time_watcher (this, &io_manager::idle_cb); 271
234 idle->start (0); 272 tw0.start (TSTAMP_MAX);
273#endif
235} 274}
236 275
237io_manager::~io_manager () 276io_manager::~io_manager ()
238{ 277{
239 iom_valid = false; 278 iom_valid = false;

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