1 |
pcg |
1.1 |
/* |
2 |
root |
1.23 |
iom.C -- generic I/O multiplexer |
3 |
root |
1.30 |
Copyright (C) 2003, 2004 Marc Lehmann <gvpe@schmorp.de> |
4 |
pcg |
1.1 |
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5 |
root |
1.30 |
This file is part of GVPE. |
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GVPE is free software; you can redistribute it and/or modify |
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pcg |
1.1 |
it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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root |
1.30 |
along with gvpe; if not, write to the Free Software |
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root |
1.29 |
Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
20 |
pcg |
1.1 |
*/ |
21 |
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22 |
root |
1.19 |
#include "iom.h" |
23 |
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24 |
pcg |
1.1 |
#include <cstdio> |
25 |
pcg |
1.8 |
#include <cstdlib> |
26 |
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#include <cerrno> |
27 |
pcg |
1.1 |
|
28 |
pcg |
1.11 |
#include <sys/time.h> |
29 |
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|
30 |
pcg |
1.16 |
#include <assert.h> |
31 |
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|
32 |
pcg |
1.14 |
#if 1 // older unices need these includes for select (2) |
33 |
pcg |
1.11 |
# include <unistd.h> |
34 |
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# include <sys/types.h> |
35 |
root |
1.19 |
# include <time.h> |
36 |
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#endif |
37 |
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38 |
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// for IOM_SIG |
39 |
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#if IOM_SIG |
40 |
root |
1.27 |
# include <csignal> |
41 |
root |
1.19 |
# include <fcntl.h> |
42 |
pcg |
1.11 |
#endif |
43 |
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44 |
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// if the BSDs would at least be marginally POSIX-compatible.. *sigh* |
45 |
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// until that happens, sys/select.h must come last |
46 |
pcg |
1.1 |
#include <sys/select.h> |
47 |
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|
48 |
root |
1.19 |
#define TIMEVAL timeval |
49 |
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#define TV_FRAC tv_usec |
50 |
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#define TV_MULT 1000000L |
51 |
pcg |
1.1 |
|
52 |
root |
1.19 |
#if IOM_IO |
53 |
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static io_manager_vec<io_watcher> iow; |
54 |
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#endif |
55 |
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#if IOM_CHECK |
56 |
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static io_manager_vec<check_watcher> cw; |
57 |
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#endif |
58 |
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#if IOM_TIME |
59 |
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static io_manager_vec<time_watcher> tw; |
60 |
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#endif |
61 |
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#if IOM_IDLE |
62 |
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static io_manager_vec<idle_watcher> iw; |
63 |
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#endif |
64 |
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#if IOM_SIG |
65 |
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static int sigpipe[2]; // signal signalling pipe |
66 |
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static sigset_t sigs; |
67 |
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struct sig_vec : io_manager_vec<sig_watcher> { |
68 |
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int pending; |
69 |
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sig_vec () |
70 |
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: pending (false) |
71 |
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{ } |
72 |
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}; |
73 |
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static vector<sig_vec *> sw; |
74 |
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#endif |
75 |
pcg |
1.8 |
|
76 |
pcg |
1.10 |
// this is a dummy time watcher to ensure that the first |
77 |
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// time watcher is _always_ valid, this gets rid of a lot |
78 |
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// of null-pointer-checks |
79 |
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// (must come _before_ iom is being defined) |
80 |
pcg |
1.13 |
static struct tw0 : time_watcher |
81 |
pcg |
1.10 |
{ |
82 |
pcg |
1.13 |
void cb (time_watcher &w) |
83 |
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{ |
84 |
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// should never get called |
85 |
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// reached end-of-time, or tstamp has a bogus definition, |
86 |
root |
1.17 |
// or compiler initialisation order broken, or something else :) |
87 |
pcg |
1.13 |
abort (); |
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} |
89 |
pcg |
1.10 |
|
90 |
pcg |
1.14 |
tw0 () |
91 |
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1.19 |
: time_watcher (this, &tw0::cb) |
92 |
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{ } |
93 |
pcg |
1.16 |
} tw0; |
94 |
pcg |
1.10 |
|
95 |
pcg |
1.1 |
tstamp NOW; |
96 |
root |
1.19 |
|
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#if IOM_TIME |
98 |
root |
1.24 |
tstamp io_manager::now () |
99 |
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1.19 |
{ |
100 |
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struct timeval tv; |
101 |
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gettimeofday (&tv, 0); |
103 |
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1.24 |
return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.; |
104 |
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} |
105 |
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void io_manager::set_now () |
107 |
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{ |
108 |
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NOW = now (); |
109 |
root |
1.19 |
} |
110 |
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#endif |
111 |
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112 |
pcg |
1.8 |
static bool iom_valid; |
113 |
root |
1.19 |
|
114 |
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// used for initialisation only |
115 |
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static struct init { |
116 |
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init () |
117 |
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{ |
118 |
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#if IOM_SIG |
119 |
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sigemptyset (&sigs); |
120 |
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121 |
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if (pipe (sigpipe)) |
122 |
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{ |
123 |
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perror ("io_manager: unable to create signal pipe, aborting."); |
124 |
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abort (); |
125 |
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} |
126 |
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127 |
root |
1.25 |
fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC); |
128 |
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fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC); |
129 |
root |
1.19 |
#endif |
130 |
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131 |
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iom_valid = true; |
132 |
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133 |
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#if IOM_TIME |
134 |
root |
1.24 |
io_manager::set_now (); |
135 |
root |
1.19 |
|
136 |
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tw0.start (TSTAMP_MAX); |
137 |
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#endif |
138 |
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} |
139 |
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140 |
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static void required (); |
141 |
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} init; |
142 |
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143 |
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void |
144 |
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init::required () |
145 |
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{ |
146 |
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if (!iom_valid) |
147 |
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{ |
148 |
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write (2, "io_manager: early registration attempt, aborting.\n", |
149 |
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sizeof ("io_manager: early registration attempt, aborting.\n") - 1); |
150 |
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abort (); |
151 |
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} |
152 |
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} |
153 |
pcg |
1.1 |
|
154 |
pcg |
1.4 |
template<class watcher> |
155 |
root |
1.19 |
void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue) |
156 |
pcg |
1.4 |
{ |
157 |
root |
1.19 |
init::required (); |
158 |
pcg |
1.8 |
|
159 |
root |
1.19 |
if (!w.active) |
160 |
pcg |
1.8 |
{ |
161 |
root |
1.19 |
queue.push_back (&w); |
162 |
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w.active = queue.size (); |
163 |
pcg |
1.8 |
} |
164 |
pcg |
1.4 |
} |
165 |
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166 |
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template<class watcher> |
167 |
root |
1.19 |
void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue) |
168 |
pcg |
1.4 |
{ |
169 |
pcg |
1.8 |
if (!iom_valid) |
170 |
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return; |
171 |
pcg |
1.4 |
|
172 |
root |
1.19 |
if (w.active) |
173 |
pcg |
1.8 |
{ |
174 |
root |
1.19 |
queue [w.active - 1] = 0; |
175 |
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w.active = 0; |
176 |
pcg |
1.8 |
} |
177 |
pcg |
1.4 |
} |
178 |
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179 |
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#if IOM_TIME |
180 |
pcg |
1.1 |
void time_watcher::trigger () |
181 |
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{ |
182 |
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call (*this); |
183 |
root |
1.19 |
io_manager::reg (*this); |
184 |
pcg |
1.1 |
} |
185 |
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186 |
root |
1.19 |
void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); } |
187 |
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void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); } |
188 |
pcg |
1.8 |
#endif |
189 |
pcg |
1.3 |
|
190 |
pcg |
1.8 |
#if IOM_IO |
191 |
root |
1.19 |
void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); } |
192 |
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void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); } |
193 |
pcg |
1.4 |
#endif |
194 |
pcg |
1.1 |
|
195 |
pcg |
1.4 |
#if IOM_CHECK |
196 |
root |
1.19 |
void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); } |
197 |
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void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); } |
198 |
pcg |
1.4 |
#endif |
199 |
pcg |
1.1 |
|
200 |
pcg |
1.7 |
#if IOM_IDLE |
201 |
root |
1.19 |
void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); } |
202 |
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void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); } |
203 |
pcg |
1.7 |
#endif |
204 |
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205 |
root |
1.19 |
#if IOM_SIG |
206 |
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static void |
207 |
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sighandler (int signum) |
208 |
pcg |
1.1 |
{ |
209 |
root |
1.19 |
sw [signum - 1]->pending = true; |
210 |
pcg |
1.1 |
|
211 |
root |
1.19 |
// we use a pipe for signal notifications, as most current |
212 |
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// OSes (Linux...) do not implement pselect correctly. ugh. |
213 |
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char ch = signum; // actual content not used |
214 |
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write (sigpipe[1], &ch, 1); |
215 |
pcg |
1.16 |
} |
216 |
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217 |
root |
1.19 |
void io_manager::reg (sig_watcher &w) |
218 |
pcg |
1.16 |
{ |
219 |
root |
1.19 |
assert (0 < w.signum); |
220 |
pcg |
1.16 |
|
221 |
root |
1.19 |
sw.reserve (w.signum); |
222 |
pcg |
1.16 |
|
223 |
root |
1.19 |
while (sw.size () < w.signum) // pathetic |
224 |
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sw.push_back (0); |
225 |
pcg |
1.16 |
|
226 |
root |
1.19 |
sig_vec *&sv = sw[w.signum - 1]; |
227 |
pcg |
1.16 |
|
228 |
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if (!sv) |
229 |
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{ |
230 |
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sv = new sig_vec; |
231 |
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232 |
root |
1.19 |
sigaddset (&sigs, w.signum); |
233 |
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sigprocmask (SIG_BLOCK, &sigs, NULL); |
234 |
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|
235 |
pcg |
1.16 |
struct sigaction sa; |
236 |
root |
1.19 |
sa.sa_handler = sighandler; |
237 |
pcg |
1.16 |
sigfillset (&sa.sa_mask); |
238 |
root |
1.19 |
sa.sa_flags = SA_RESTART; |
239 |
pcg |
1.16 |
|
240 |
root |
1.19 |
if (sigaction (w.signum, &sa, 0)) |
241 |
pcg |
1.16 |
{ |
242 |
root |
1.19 |
perror ("io_manager: error while installing signal handler, ignoring."); |
243 |
pcg |
1.16 |
abort (); |
244 |
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} |
245 |
root |
1.19 |
|
246 |
pcg |
1.16 |
} |
247 |
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|
248 |
root |
1.19 |
io_manager::reg (w, *sv); |
249 |
pcg |
1.16 |
} |
250 |
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|
251 |
root |
1.19 |
void io_manager::unreg (sig_watcher &w) |
252 |
pcg |
1.16 |
{ |
253 |
root |
1.19 |
if (!w.active) |
254 |
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return; |
255 |
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|
256 |
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assert (0 < w.signum && w.signum <= sw.size ()); |
257 |
pcg |
1.16 |
|
258 |
root |
1.19 |
io_manager::unreg (w, *sw[w.signum - 1]); |
259 |
pcg |
1.16 |
} |
260 |
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261 |
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void sig_watcher::start (int signum) |
262 |
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{ |
263 |
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stop (); |
264 |
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this->signum = signum; |
265 |
root |
1.19 |
io_manager::reg (*this); |
266 |
pcg |
1.16 |
} |
267 |
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#endif |
268 |
root |
1.19 |
|
269 |
pcg |
1.1 |
void io_manager::loop () |
270 |
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{ |
271 |
root |
1.19 |
init::required (); |
272 |
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|
273 |
pcg |
1.4 |
#if IOM_TIME |
274 |
pcg |
1.1 |
set_now (); |
275 |
pcg |
1.4 |
#endif |
276 |
pcg |
1.1 |
|
277 |
|
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for (;;) |
278 |
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{ |
279 |
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|
280 |
pcg |
1.7 |
#if IOM_TIME |
281 |
root |
1.23 |
// call pending time watchers |
282 |
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{ |
283 |
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bool activity; |
284 |
pcg |
1.1 |
|
285 |
root |
1.23 |
do |
286 |
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{ |
287 |
|
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activity = false; |
288 |
pcg |
1.1 |
|
289 |
root |
1.23 |
for (int i = tw.size (); i--; ) |
290 |
|
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if (!tw[i]) |
291 |
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tw.erase_unordered (i); |
292 |
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else if (tw[i]->at <= NOW) |
293 |
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{ |
294 |
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time_watcher &w = *tw[i]; |
295 |
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|
296 |
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unreg (w); |
297 |
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w.call (w); |
298 |
pcg |
1.7 |
|
299 |
root |
1.23 |
activity = true; |
300 |
pcg |
1.7 |
} |
301 |
root |
1.23 |
} |
302 |
|
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while (activity); |
303 |
|
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} |
304 |
pcg |
1.7 |
#endif |
305 |
pcg |
1.6 |
|
306 |
|
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#if IOM_CHECK |
307 |
root |
1.23 |
// call all check watchers |
308 |
pcg |
1.8 |
for (int i = cw.size (); i--; ) |
309 |
|
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if (!cw[i]) |
310 |
|
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cw.erase_unordered (i); |
311 |
|
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else |
312 |
|
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cw[i]->call (*cw[i]); |
313 |
root |
1.23 |
#endif |
314 |
pcg |
1.12 |
|
315 |
root |
1.23 |
struct TIMEVAL *to = 0; |
316 |
|
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struct TIMEVAL tval; |
317 |
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|
318 |
|
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#if IOM_IDLE |
319 |
|
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if (iw.size ()) |
320 |
pcg |
1.12 |
{ |
321 |
|
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tval.tv_sec = 0; |
322 |
root |
1.19 |
tval.TV_FRAC = 0; |
323 |
pcg |
1.12 |
to = &tval; |
324 |
|
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} |
325 |
root |
1.23 |
else |
326 |
|
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#endif |
327 |
|
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{ |
328 |
|
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#if IOM_TIME |
329 |
|
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// find earliest active watcher |
330 |
|
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time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times |
331 |
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|
332 |
|
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for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); ) |
333 |
|
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if (*i && (*i)->at < next->at) |
334 |
|
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next = *i; |
335 |
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|
336 |
|
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if (next->at > NOW && next != tw[0]) |
337 |
|
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{ |
338 |
|
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double diff = next->at - NOW; |
339 |
|
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tval.tv_sec = (int)diff; |
340 |
|
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tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT); |
341 |
|
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to = &tval; |
342 |
|
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} |
343 |
|
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} |
344 |
pcg |
1.4 |
#endif |
345 |
pcg |
1.1 |
|
346 |
root |
1.19 |
#if IOM_IO || IOM_SIG |
347 |
pcg |
1.15 |
fd_set rfd, wfd; |
348 |
pcg |
1.1 |
|
349 |
|
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FD_ZERO (&rfd); |
350 |
|
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FD_ZERO (&wfd); |
351 |
|
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|
352 |
|
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int fds = 0; |
353 |
|
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|
354 |
root |
1.19 |
# if IOM_IO |
355 |
root |
1.23 |
for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); ) |
356 |
pcg |
1.8 |
if (*i) |
357 |
|
|
{ |
358 |
|
|
if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); |
359 |
|
|
if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); |
360 |
pcg |
1.1 |
|
361 |
pcg |
1.8 |
if ((*i)->fd >= fds) fds = (*i)->fd + 1; |
362 |
|
|
} |
363 |
root |
1.19 |
# endif |
364 |
pcg |
1.1 |
|
365 |
root |
1.23 |
if (!to && !fds) //TODO: also check idle_watchers and check_watchers? |
366 |
pcg |
1.5 |
break; // no events |
367 |
|
|
|
368 |
root |
1.19 |
# if IOM_SIG |
369 |
|
|
FD_SET (sigpipe[0], &rfd); |
370 |
|
|
if (sigpipe[0] >= fds) fds = sigpipe[0] + 1; |
371 |
|
|
# endif |
372 |
|
|
|
373 |
|
|
# if IOM_SIG |
374 |
|
|
// there is no race, as we use a pipe for signals, so select |
375 |
|
|
// will return if a signal is caught. |
376 |
|
|
sigprocmask (SIG_UNBLOCK, &sigs, NULL); |
377 |
|
|
# endif |
378 |
pcg |
1.15 |
fds = select (fds, &rfd, &wfd, NULL, to); |
379 |
root |
1.19 |
# if IOM_SIG |
380 |
|
|
sigprocmask (SIG_BLOCK, &sigs, NULL); |
381 |
|
|
# endif |
382 |
|
|
|
383 |
pcg |
1.4 |
# if IOM_TIME |
384 |
root |
1.28 |
{ |
385 |
|
|
// update time, try to compensate for gross non-monotonic time changes |
386 |
|
|
tstamp diff = NOW; |
387 |
|
|
set_now (); |
388 |
|
|
diff = NOW - diff; |
389 |
|
|
|
390 |
|
|
if (diff < 0) |
391 |
|
|
for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); ) |
392 |
|
|
if (*i) |
393 |
|
|
(*i)->at += diff; |
394 |
|
|
} |
395 |
pcg |
1.4 |
# endif |
396 |
pcg |
1.1 |
|
397 |
|
|
if (fds > 0) |
398 |
root |
1.19 |
{ |
399 |
|
|
# if IOM_SIG |
400 |
|
|
if (FD_ISSET (sigpipe[0], &rfd)) |
401 |
pcg |
1.8 |
{ |
402 |
root |
1.19 |
char ch; |
403 |
|
|
|
404 |
|
|
while (read (sigpipe[0], &ch, 1) > 0) |
405 |
|
|
; |
406 |
pcg |
1.1 |
|
407 |
root |
1.23 |
for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); ) |
408 |
root |
1.19 |
if (*svp && (*svp)->pending) |
409 |
|
|
{ |
410 |
|
|
sig_vec &sv = **svp; |
411 |
|
|
for (int i = sv.size (); i--; ) |
412 |
|
|
if (!sv[i]) |
413 |
|
|
sv.erase_unordered (i); |
414 |
|
|
else |
415 |
|
|
sv[i]->call (*sv[i]); |
416 |
pcg |
1.4 |
|
417 |
root |
1.19 |
sv.pending = false; |
418 |
|
|
} |
419 |
pcg |
1.8 |
} |
420 |
root |
1.19 |
# endif |
421 |
|
|
|
422 |
|
|
# if IOM_IO |
423 |
|
|
for (int i = iow.size (); i--; ) |
424 |
|
|
if (!iow[i]) |
425 |
|
|
iow.erase_unordered (i); |
426 |
|
|
else |
427 |
|
|
{ |
428 |
root |
1.27 |
io_watcher &w = *iow[i]; |
429 |
|
|
short revents = w.events; |
430 |
root |
1.19 |
|
431 |
root |
1.27 |
if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ; |
432 |
|
|
if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE; |
433 |
root |
1.19 |
|
434 |
|
|
if (revents) |
435 |
root |
1.27 |
w.call (w, revents); |
436 |
root |
1.19 |
} |
437 |
|
|
#endif |
438 |
|
|
} |
439 |
pcg |
1.8 |
else if (fds < 0 && errno != EINTR) |
440 |
|
|
{ |
441 |
root |
1.19 |
perror ("io_manager: fatal error while waiting for I/O or time event, aborting."); |
442 |
pcg |
1.8 |
abort (); |
443 |
|
|
} |
444 |
pcg |
1.7 |
#if IOM_IDLE |
445 |
pcg |
1.8 |
else |
446 |
|
|
for (int i = iw.size (); i--; ) |
447 |
|
|
if (!iw[i]) |
448 |
|
|
iw.erase_unordered (i); |
449 |
|
|
else |
450 |
|
|
iw[i]->call (*iw[i]); |
451 |
pcg |
1.7 |
#endif |
452 |
|
|
|
453 |
pcg |
1.4 |
#elif IOM_TIME |
454 |
pcg |
1.5 |
if (!to) |
455 |
|
|
break; |
456 |
|
|
|
457 |
pcg |
1.4 |
select (0, 0, 0, 0, &to); |
458 |
|
|
set_now (); |
459 |
pcg |
1.5 |
#else |
460 |
|
|
break; |
461 |
pcg |
1.4 |
#endif |
462 |
pcg |
1.5 |
} |
463 |
pcg |
1.1 |
} |
464 |
|
|
|