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48f44632 | 1 | /* |
f43e2ec2 | 2 | * DEBUG: section 41 Event Processing |
48f44632 | 3 | * AUTHOR: Henrik Nordstrom |
4 | * | |
2b6662ba | 5 | * SQUID Web Proxy Cache http://www.squid-cache.org/ |
e25c139f | 6 | * ---------------------------------------------------------- |
48f44632 | 7 | * |
2b6662ba | 8 | * Squid is the result of efforts by numerous individuals from |
9 | * the Internet community; see the CONTRIBUTORS file for full | |
10 | * details. Many organizations have provided support for Squid's | |
11 | * development; see the SPONSORS file for full details. Squid is | |
12 | * Copyrighted (C) 2001 by the Regents of the University of | |
13 | * California; see the COPYRIGHT file for full details. Squid | |
14 | * incorporates software developed and/or copyrighted by other | |
15 | * sources; see the CREDITS file for full details. | |
48f44632 | 16 | * |
17 | * This program is free software; you can redistribute it and/or modify | |
18 | * it under the terms of the GNU General Public License as published by | |
19 | * the Free Software Foundation; either version 2 of the License, or | |
20 | * (at your option) any later version. | |
26ac0430 | 21 | * |
48f44632 | 22 | * This program is distributed in the hope that it will be useful, |
23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
25 | * GNU General Public License for more details. | |
26ac0430 | 26 | * |
48f44632 | 27 | * You should have received a copy of the GNU General Public License |
28 | * along with this program; if not, write to the Free Software | |
cbdec147 | 29 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. |
e25c139f | 30 | * |
48f44632 | 31 | */ |
32 | ||
f7f3304a | 33 | #include "squid.h" |
27bc2077 | 34 | #include "compat/drand48.h" |
27bc2077 | 35 | #include "event.h" |
8822ebee | 36 | #include "mgr/Registration.h" |
582c2af2 | 37 | #include "profiler/Profiler.h" |
602d9612 A |
38 | #include "SquidTime.h" |
39 | #include "Store.h" | |
5bed43d6 | 40 | #include "tools.h" |
48f44632 | 41 | |
074d6a40 | 42 | #include <cmath> |
aa14d759 | 43 | |
48f44632 | 44 | /* The list of event processes */ |
62e76326 | 45 | |
4ba55996 | 46 | static OBJH eventDump; |
236b1f2a | 47 | static const char *last_event_ran = NULL; |
48f44632 | 48 | |
26ac0430 | 49 | // This AsyncCall dialer can be configured to check that the event cbdata is |
5dee3116 | 50 | // valid before calling the event handler |
51 | class EventDialer: public CallDialer | |
52 | { | |
53 | public: | |
54 | typedef CallDialer Parent; | |
55 | ||
56 | EventDialer(EVH *aHandler, void *anArg, bool lockedArg); | |
57 | EventDialer(const EventDialer &d); | |
58 | virtual ~EventDialer(); | |
59 | ||
60 | virtual void print(std::ostream &os) const; | |
61 | virtual bool canDial(AsyncCall &call); | |
62 | ||
63 | void dial(AsyncCall &) { theHandler(theArg); } | |
64 | ||
65 | private: | |
66 | EVH *theHandler; | |
67 | void *theArg; | |
68 | bool isLockedArg; | |
69 | }; | |
70 | ||
71 | EventDialer::EventDialer(EVH *aHandler, void *anArg, bool lockedArg): | |
26ac0430 | 72 | theHandler(aHandler), theArg(anArg), isLockedArg(lockedArg) |
5dee3116 | 73 | { |
74 | if (isLockedArg) | |
451bde6d | 75 | (void)cbdataReference(theArg); |
5dee3116 | 76 | } |
77 | ||
78 | EventDialer::EventDialer(const EventDialer &d): | |
26ac0430 | 79 | theHandler(d.theHandler), theArg(d.theArg), isLockedArg(d.isLockedArg) |
5dee3116 | 80 | { |
81 | if (isLockedArg) | |
451bde6d | 82 | (void)cbdataReference(theArg); |
5dee3116 | 83 | } |
84 | ||
85 | EventDialer::~EventDialer() | |
86 | { | |
87 | if (isLockedArg) | |
88 | cbdataReferenceDone(theArg); | |
89 | } | |
90 | ||
91 | bool | |
26ac0430 AJ |
92 | EventDialer::canDial(AsyncCall &call) |
93 | { | |
5dee3116 | 94 | // TODO: add Parent::canDial() that always returns true |
95 | //if (!Parent::canDial()) | |
96 | // return false; | |
97 | ||
98 | if (isLockedArg && !cbdataReferenceValid(theArg)) | |
99 | return call.cancel("stale handler data"); | |
100 | ||
101 | return true; | |
102 | } | |
103 | ||
104 | void | |
105 | EventDialer::print(std::ostream &os) const | |
106 | { | |
107 | os << '('; | |
108 | if (theArg) | |
109 | os << theArg << (isLockedArg ? "*?" : ""); | |
110 | os << ')'; | |
111 | } | |
112 | ||
d5f8d05f FC |
113 | ev_entry::ev_entry(char const * aName, EVH * aFunction, void * aArgument, double evWhen, |
114 | int aWeight, bool haveArgument) : name(aName), func(aFunction), | |
115 | arg(haveArgument ? cbdataReference(aArgument) : aArgument), when(evWhen), weight(aWeight), | |
e053c141 | 116 | cbdata(haveArgument) |
5dee3116 | 117 | { |
118 | } | |
119 | ||
120 | ev_entry::~ev_entry() | |
121 | { | |
122 | if (cbdata) | |
123 | cbdataReferenceDone(arg); | |
124 | } | |
a553a5a3 | 125 | |
48f44632 | 126 | void |
601af4c6 | 127 | eventAdd(const char *name, EVH * func, void *arg, double when, int weight, bool cbdata) |
48f44632 | 128 | { |
a553a5a3 | 129 | EventScheduler::GetInstance()->schedule(name, func, arg, when, weight, cbdata); |
48f44632 | 130 | } |
131 | ||
8f3db324 | 132 | /* same as eventAdd but adds a random offset within +-1/3 of delta_ish */ |
133 | void | |
52040193 | 134 | eventAddIsh(const char *name, EVH * func, void *arg, double delta_ish, int weight) |
8f3db324 | 135 | { |
52040193 | 136 | if (delta_ish >= 3.0) { |
62e76326 | 137 | const double two_third = (2.0 * delta_ish) / 3.0; |
138 | delta_ish = two_third + (drand48() * two_third); | |
139 | /* | |
140 | * I'm sure drand48() isn't portable. Tell me what function | |
141 | * you have that returns a random double value in the range 0,1. | |
142 | */ | |
8f3db324 | 143 | } |
62e76326 | 144 | |
f720985e | 145 | eventAdd(name, func, arg, delta_ish, weight); |
8f3db324 | 146 | } |
147 | ||
93775f90 | 148 | void |
582b6456 | 149 | eventDelete(EVH * func, void *arg) |
93775f90 | 150 | { |
a553a5a3 | 151 | EventScheduler::GetInstance()->cancel(func, arg); |
152 | } | |
62e76326 | 153 | |
a553a5a3 | 154 | void |
15b3c0d7 | 155 | eventInit(void) |
a553a5a3 | 156 | { |
8822ebee | 157 | Mgr::RegisterAction("events", "Event Queue", eventDump, 0, 1); |
a553a5a3 | 158 | } |
62e76326 | 159 | |
a553a5a3 | 160 | static void |
161 | eventDump(StoreEntry * sentry) | |
162 | { | |
163 | EventScheduler::GetInstance()->dump(sentry); | |
164 | } | |
165 | ||
166 | void | |
167 | eventFreeMemory(void) | |
168 | { | |
169 | EventScheduler::GetInstance()->clean(); | |
170 | } | |
171 | ||
172 | int | |
173 | eventFind(EVH * func, void *arg) | |
174 | { | |
175 | return EventScheduler::GetInstance()->find(func, arg); | |
176 | } | |
177 | ||
5dee3116 | 178 | EventScheduler EventScheduler::_instance; |
a553a5a3 | 179 | |
5dee3116 | 180 | EventScheduler::EventScheduler(): tasks(NULL) |
a553a5a3 | 181 | {} |
182 | ||
183 | EventScheduler::~EventScheduler() | |
184 | { | |
185 | clean(); | |
186 | } | |
187 | ||
188 | void | |
189 | EventScheduler::cancel(EVH * func, void *arg) | |
190 | { | |
191 | ev_entry **E; | |
192 | ev_entry *event; | |
62e76326 | 193 | |
79d39a72 | 194 | for (E = &tasks; (event = *E) != NULL; E = &(*E)->next) { |
62e76326 | 195 | if (event->func != func) |
196 | continue; | |
197 | ||
aa93f210 | 198 | if (arg && event->arg != arg) |
62e76326 | 199 | continue; |
200 | ||
201 | *E = event->next; | |
202 | ||
62ee09ca | 203 | delete event; |
62e76326 | 204 | |
26ac0430 AJ |
205 | if (arg) |
206 | return; | |
207 | /* | |
208 | * DPW 2007-04-12 | |
209 | * Since this method may now delete multiple events (when | |
210 | * arg is NULL) it no longer returns after a deletion and | |
211 | * we have a potential NULL pointer problem. If we just | |
212 | * deleted the last event in the list then *E is now equal | |
213 | * to NULL. We need to break here or else we'll get a NULL | |
214 | * pointer dereference in the last clause of the for loop. | |
215 | */ | |
216 | if (NULL == *E) | |
217 | break; | |
93775f90 | 218 | } |
62e76326 | 219 | |
aa93f210 | 220 | if (arg) |
26ac0430 | 221 | debug_trap("eventDelete: event not found"); |
93775f90 | 222 | } |
223 | ||
aa14d759 AR |
224 | // The event API does not guarantee exact timing, but guarantees that no event |
225 | // is fired before it is due. We may delay firing, but never fire too early. | |
a553a5a3 | 226 | int |
aa14d759 | 227 | EventScheduler::timeRemaining() const |
a553a5a3 | 228 | { |
229 | if (!tasks) | |
aa839030 | 230 | return EVENT_IDLE; |
a553a5a3 | 231 | |
aa14d759 AR |
232 | if (tasks->when <= current_dtime) // we are on time or late |
233 | return 0; // fire the event ASAP | |
8ff3fa2e | 234 | |
aa14d759 AR |
235 | const double diff = tasks->when - current_dtime; // microseconds |
236 | // Round UP: If we come back a nanosecond earlier, we will wait again! | |
237 | const int timeLeft = static_cast<int>(ceil(1000*diff)); // milliseconds | |
238 | // Avoid hot idle: A series of rapid select() calls with zero timeout. | |
239 | const int minDelay = 1; // millisecond | |
240 | return max(minDelay, timeLeft); | |
a553a5a3 | 241 | } |
242 | ||
243 | int | |
8ff3fa2e | 244 | EventScheduler::checkEvents(int timeout) |
48f44632 | 245 | { |
aa14d759 AR |
246 | int result = timeRemaining(); |
247 | if (result != 0) | |
248 | return result; | |
62e76326 | 249 | |
1d5161bd | 250 | PROF_start(eventRun); |
251 | ||
aa14d759 AR |
252 | do { |
253 | ev_entry *event = tasks; | |
254 | assert(event); | |
62e76326 | 255 | |
5dee3116 | 256 | /* XXX assumes event->name is static memory! */ |
257 | AsyncCall::Pointer call = asyncCall(41,5, event->name, | |
26ac0430 | 258 | EventDialer(event->func, event->arg, event->cbdata)); |
5dee3116 | 259 | ScheduleCallHere(call); |
260 | ||
261 | last_event_ran = event->name; // XXX: move this to AsyncCallQueue | |
262 | const bool heavy = event->weight && | |
26ac0430 | 263 | (!event->cbdata || cbdataReferenceValid(event->arg)); |
62e76326 | 264 | |
265 | tasks = event->next; | |
5dee3116 | 266 | delete event; |
62e76326 | 267 | |
aa14d759 AR |
268 | result = timeRemaining(); |
269 | ||
5dee3116 | 270 | // XXX: We may be called again during the same event loop iteration. |
271 | // Is there a point in breaking now? | |
26ac0430 | 272 | if (heavy) |
5dee3116 | 273 | break; // do not dequeue events following a heavy event |
aa14d759 | 274 | } while (result == 0); |
1d5161bd | 275 | |
276 | PROF_stop(eventRun); | |
aa14d759 | 277 | return result; |
48f44632 | 278 | } |
279 | ||
a553a5a3 | 280 | void |
281 | EventScheduler::clean() | |
48f44632 | 282 | { |
a553a5a3 | 283 | while (ev_entry * event = tasks) { |
284 | tasks = event->next; | |
a553a5a3 | 285 | delete event; |
286 | } | |
287 | ||
288 | tasks = NULL; | |
4ba55996 | 289 | } |
290 | ||
a553a5a3 | 291 | void |
292 | EventScheduler::dump(StoreEntry * sentry) | |
4ba55996 | 293 | { |
62e76326 | 294 | |
cb9f32a9 | 295 | ev_entry *e = tasks; |
62e76326 | 296 | |
236b1f2a | 297 | if (last_event_ran) |
62e76326 | 298 | storeAppendPrintf(sentry, "Last event to run: %s\n\n", last_event_ran); |
299 | ||
cc192b50 | 300 | storeAppendPrintf(sentry, "%-25s\t%-15s\t%s\t%s\n", |
62e76326 | 301 | "Operation", |
302 | "Next Execution", | |
303 | "Weight", | |
304 | "Callback Valid?"); | |
305 | ||
4ba55996 | 306 | while (e != NULL) { |
cc192b50 | 307 | storeAppendPrintf(sentry, "%-25s\t%0.3f sec\t%5d\t %s\n", |
32f10aa5 | 308 | e->name, e->when ? e->when - current_dtime : 0, e->weight, |
601af4c6 | 309 | (e->arg && e->cbdata) ? cbdataReferenceValid(e->arg) ? "yes" : "no" : "N/A"); |
62e76326 | 310 | e = e->next; |
4ba55996 | 311 | } |
312 | } | |
f1fc2a8d | 313 | |
a553a5a3 | 314 | bool |
315 | EventScheduler::find(EVH * func, void * arg) | |
f1fc2a8d | 316 | { |
62e76326 | 317 | |
cb9f32a9 | 318 | ev_entry *event; |
62e76326 | 319 | |
a553a5a3 | 320 | for (event = tasks; event != NULL; event = event->next) { |
321 | if (event->func == func && event->arg == arg) | |
322 | return true; | |
f1fc2a8d | 323 | } |
62e76326 | 324 | |
a553a5a3 | 325 | return false; |
f1fc2a8d | 326 | } |
46ca5fc6 | 327 | |
a553a5a3 | 328 | EventScheduler * |
329 | EventScheduler::GetInstance() | |
46ca5fc6 | 330 | { |
a553a5a3 | 331 | return &_instance; |
332 | } | |
62e76326 | 333 | |
a553a5a3 | 334 | void |
335 | EventScheduler::schedule(const char *name, EVH * func, void *arg, double when, int weight, bool cbdata) | |
336 | { | |
a5a02499 | 337 | // Use zero timestamp for when=0 events: Many of them are async calls that |
338 | // must fire in the submission order. We cannot use current_dtime for them | |
339 | // because it may decrease if system clock is adjusted backwards. | |
340 | const double timestamp = when > 0.0 ? current_dtime + when : 0; | |
cb9f32a9 | 341 | ev_entry *event = new ev_entry(name, func, arg, timestamp, weight, cbdata); |
a553a5a3 | 342 | |
cb9f32a9 | 343 | ev_entry **E; |
d65986ae | 344 | debugs(41, 7, HERE << "schedule: Adding '" << name << "', in " << when << " seconds"); |
a553a5a3 | 345 | /* Insert after the last event with the same or earlier time */ |
346 | ||
347 | for (E = &tasks; *E; E = &(*E)->next) { | |
348 | if ((*E)->when > event->when) | |
349 | break; | |
46ca5fc6 | 350 | } |
62e76326 | 351 | |
a553a5a3 | 352 | event->next = *E; |
353 | *E = event; | |
46ca5fc6 | 354 | } |