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9a9954ba | 1 | /* |
f70aedc4 | 2 | * Copyright (C) 1996-2021 The Squid Software Foundation and contributors |
9a9954ba | 3 | * |
bbc27441 AJ |
4 | * Squid software is distributed under GPLv2+ license and includes |
5 | * contributions from numerous individuals and organizations. | |
6 | * Please see the COPYING and CONTRIBUTORS files for details. | |
9a9954ba AR |
7 | */ |
8 | ||
bbc27441 AJ |
9 | /* DEBUG: section 20 Storage Manager */ |
10 | ||
9a9954ba AR |
11 | #include "squid.h" |
12 | #include "base/RunnersRegistry.h" | |
e4d13993 | 13 | #include "CollapsedForwarding.h" |
9a9954ba AR |
14 | #include "HttpReply.h" |
15 | #include "ipc/mem/Page.h" | |
16 | #include "ipc/mem/Pages.h" | |
17 | #include "MemObject.h" | |
9a9954ba AR |
18 | #include "mime_header.h" |
19 | #include "SquidConfig.h" | |
20 | #include "SquidMath.h" | |
21 | #include "StoreStats.h" | |
22 | #include "tools.h" | |
e4d13993 | 23 | #include "Transients.h" |
9a9954ba | 24 | |
9a9954ba | 25 | #include <limits> |
9a9954ba | 26 | |
1860fbac AR |
27 | /// shared memory segment path to use for Transients map |
28 | static const SBuf MapLabel("transients_map"); | |
9a9954ba | 29 | |
6919be24 | 30 | Transients::Transients(): map(NULL), locals(NULL) |
9a9954ba | 31 | { |
9a9954ba AR |
32 | } |
33 | ||
34 | Transients::~Transients() | |
35 | { | |
36 | delete map; | |
6919be24 | 37 | delete locals; |
9a9954ba AR |
38 | } |
39 | ||
40 | void | |
41 | Transients::init() | |
42 | { | |
daed75a9 | 43 | assert(Enabled()); |
9a9954ba | 44 | const int64_t entryLimit = EntryLimit(); |
daed75a9 | 45 | assert(entryLimit > 0); |
9a9954ba AR |
46 | |
47 | Must(!map); | |
48 | map = new TransientsMap(MapLabel); | |
49 | map->cleaner = this; | |
b2aca62a | 50 | map->disableHitValidation(); // Transients lacks slices to validate |
6919be24 | 51 | |
8bcca0f8 | 52 | locals = new Locals(entryLimit, 0); |
9a9954ba AR |
53 | } |
54 | ||
55 | void | |
56 | Transients::getStats(StoreInfoStats &stats) const | |
57 | { | |
58 | #if TRANSIENT_STATS_SUPPORTED | |
59 | const size_t pageSize = Ipc::Mem::PageSize(); | |
60 | ||
61 | stats.mem.shared = true; | |
62 | stats.mem.capacity = | |
63 | Ipc::Mem::PageLimit(Ipc::Mem::PageId::cachePage) * pageSize; | |
64 | stats.mem.size = | |
65 | Ipc::Mem::PageLevel(Ipc::Mem::PageId::cachePage) * pageSize; | |
66 | stats.mem.count = currentCount(); | |
67 | #endif | |
68 | } | |
69 | ||
70 | void | |
71 | Transients::stat(StoreEntry &e) const | |
72 | { | |
73 | storeAppendPrintf(&e, "\n\nTransient Objects\n"); | |
74 | ||
75 | storeAppendPrintf(&e, "Maximum Size: %.0f KB\n", maxSize()/1024.0); | |
76 | storeAppendPrintf(&e, "Current Size: %.2f KB %.2f%%\n", | |
77 | currentSize() / 1024.0, | |
78 | Math::doublePercent(currentSize(), maxSize())); | |
79 | ||
80 | if (map) { | |
81 | const int limit = map->entryLimit(); | |
82 | storeAppendPrintf(&e, "Maximum entries: %9d\n", limit); | |
83 | if (limit > 0) { | |
84 | storeAppendPrintf(&e, "Current entries: %" PRId64 " %.2f%%\n", | |
85 | currentCount(), (100.0 * currentCount() / limit)); | |
86 | } | |
87 | } | |
88 | } | |
89 | ||
90 | void | |
91 | Transients::maintain() | |
92 | { | |
e4d13993 | 93 | // no lazy garbage collection needed |
9a9954ba AR |
94 | } |
95 | ||
96 | uint64_t | |
97 | Transients::minSize() const | |
98 | { | |
99 | return 0; // XXX: irrelevant, but Store parent forces us to implement this | |
100 | } | |
101 | ||
102 | uint64_t | |
103 | Transients::maxSize() const | |
104 | { | |
105 | // Squid currently does not limit the total size of all transient objects | |
106 | return std::numeric_limits<uint64_t>::max(); | |
107 | } | |
108 | ||
109 | uint64_t | |
110 | Transients::currentSize() const | |
111 | { | |
112 | // TODO: we do not get enough information to calculate this | |
113 | // StoreEntry should update associated stores when its size changes | |
114 | return 0; | |
115 | } | |
116 | ||
117 | uint64_t | |
118 | Transients::currentCount() const | |
119 | { | |
120 | return map ? map->entryCount() : 0; | |
121 | } | |
122 | ||
123 | int64_t | |
124 | Transients::maxObjectSize() const | |
125 | { | |
126 | // Squid currently does not limit the size of a transient object | |
127 | return std::numeric_limits<uint64_t>::max(); | |
128 | } | |
129 | ||
130 | void | |
131 | Transients::reference(StoreEntry &) | |
132 | { | |
e4d13993 | 133 | // no replacement policy (but the cache(s) storing the entry may have one) |
9a9954ba AR |
134 | } |
135 | ||
136 | bool | |
2745fea5 | 137 | Transients::dereference(StoreEntry &) |
9a9954ba AR |
138 | { |
139 | // no need to keep e in the global store_table for us; we have our own map | |
140 | return false; | |
141 | } | |
142 | ||
9a9954ba AR |
143 | StoreEntry * |
144 | Transients::get(const cache_key *key) | |
145 | { | |
146 | if (!map) | |
147 | return NULL; | |
148 | ||
149 | sfileno index; | |
1bfe9ade AR |
150 | const Ipc::StoreMapAnchor *anchor = map->openForReading(key, index); |
151 | if (!anchor) | |
9a9954ba AR |
152 | return NULL; |
153 | ||
6919be24 AR |
154 | // If we already have a local entry, the store_table should have found it. |
155 | // Since it did not, the local entry key must have changed from public to | |
156 | // private. We still need to keep the private entry around for syncing as | |
157 | // its clients depend on it, but we should not allow new clients to join. | |
158 | if (StoreEntry *oldE = locals->at(index)) { | |
159 | debugs(20, 3, "not joining private " << *oldE); | |
160 | assert(EBIT_TEST(oldE->flags, KEY_PRIVATE)); | |
d1d3b4dc | 161 | map->closeForReadingAndFreeIdle(index); |
4310f8b0 | 162 | return nullptr; |
1bfe9ade | 163 | } |
4475555f | 164 | |
6c8cbe63 D |
165 | // store hadWriter before checking ENTRY_REQUIRES_COLLAPSING to avoid racing |
166 | // the writer that clears that flag and then leaves | |
167 | const auto hadWriter = map->peekAtWriter(index); | |
168 | if (!hadWriter && EBIT_TEST(anchor->basics.flags, ENTRY_REQUIRES_COLLAPSING)) { | |
169 | debugs(20, 3, "not joining abandoned entry " << index); | |
170 | map->closeForReadingAndFreeIdle(index); | |
171 | return nullptr; | |
172 | } | |
173 | ||
4310f8b0 EB |
174 | StoreEntry *e = new StoreEntry(); |
175 | e->createMemObject(); | |
5bd8ce13 | 176 | anchorEntry(*e, index, *anchor); |
6c8cbe63 | 177 | |
4310f8b0 | 178 | // keep read lock to receive updates from others |
9a9954ba AR |
179 | return e; |
180 | } | |
181 | ||
6919be24 AR |
182 | StoreEntry * |
183 | Transients::findCollapsed(const sfileno index) | |
184 | { | |
185 | if (!map) | |
186 | return NULL; | |
187 | ||
188 | if (StoreEntry *oldE = locals->at(index)) { | |
189 | debugs(20, 5, "found " << *oldE << " at " << index << " in " << MapLabel); | |
190 | assert(oldE->mem_obj && oldE->mem_obj->xitTable.index == index); | |
191 | return oldE; | |
192 | } | |
193 | ||
194 | debugs(20, 3, "no entry at " << index << " in " << MapLabel); | |
195 | return NULL; | |
196 | } | |
197 | ||
d2a6dcba EB |
198 | void |
199 | Transients::clearCollapsingRequirement(const StoreEntry &e) | |
200 | { | |
201 | assert(map); | |
202 | assert(e.hasTransients()); | |
203 | assert(isWriter(e)); | |
204 | const auto idx = e.mem_obj->xitTable.index; | |
205 | auto &anchor = map->writeableEntry(idx); | |
206 | if (EBIT_TEST(anchor.basics.flags, ENTRY_REQUIRES_COLLAPSING)) { | |
207 | EBIT_CLR(anchor.basics.flags, ENTRY_REQUIRES_COLLAPSING); | |
208 | CollapsedForwarding::Broadcast(e); | |
209 | } | |
210 | } | |
211 | ||
9a9954ba | 212 | void |
4310f8b0 | 213 | Transients::monitorIo(StoreEntry *e, const cache_key *key, const Store::IoStatus direction) |
9a9954ba | 214 | { |
4310f8b0 EB |
215 | if (!e->hasTransients()) { |
216 | addEntry(e, key, direction); | |
8253d451 | 217 | assert(e->hasTransients()); |
9d4e9cfb | 218 | } |
9a9954ba | 219 | |
4310f8b0 EB |
220 | const auto index = e->mem_obj->xitTable.index; |
221 | if (const auto old = locals->at(index)) { | |
222 | assert(old == e); | |
223 | } else { | |
224 | // We do not lock e because we do not want to prevent its destruction; | |
225 | // e is tied to us via mem_obj so we will know when it is destructed. | |
226 | locals->at(index) = e; | |
9d4e9cfb | 227 | } |
9a9954ba AR |
228 | } |
229 | ||
8253d451 | 230 | /// creates a new Transients entry |
4310f8b0 EB |
231 | void |
232 | Transients::addEntry(StoreEntry *e, const cache_key *key, const Store::IoStatus direction) | |
9a9954ba | 233 | { |
4310f8b0 EB |
234 | assert(e); |
235 | assert(e->mem_obj); | |
236 | assert(!e->hasTransients()); | |
9a9954ba | 237 | |
4310f8b0 | 238 | Must(map); // configured to track transients |
9a9954ba | 239 | |
5bd8ce13 AR |
240 | if (direction == Store::ioWriting) |
241 | return addWriterEntry(*e, key); | |
242 | ||
243 | assert(direction == Store::ioReading); | |
244 | addReaderEntry(*e, key); | |
245 | } | |
246 | ||
247 | /// addEntry() helper used for cache entry creators/writers | |
248 | void | |
249 | Transients::addWriterEntry(StoreEntry &e, const cache_key *key) | |
250 | { | |
4310f8b0 | 251 | sfileno index = 0; |
5bd8ce13 AR |
252 | const auto anchor = map->openForWriting(key, index); |
253 | if (!anchor) | |
254 | throw TextException("writer collision", Here()); | |
9a9954ba | 255 | |
8253d451 | 256 | // set ASAP in hope to unlock the slot if something throws |
5bd8ce13 AR |
257 | // and to provide index to such methods as hasWriter() |
258 | auto &xitTable = e.mem_obj->xitTable; | |
259 | xitTable.index = index; | |
260 | xitTable.io = Store::ioWriting; | |
261 | ||
262 | anchor->set(e, key); | |
263 | // allow reading and receive remote DELETE events, but do not switch to | |
264 | // the reading lock because transientReaders() callers want true readers | |
265 | map->startAppending(index); | |
266 | } | |
267 | ||
268 | /// addEntry() helper used for cache readers | |
269 | /// readers do not modify the cache, but they must create a Transients entry | |
270 | void | |
271 | Transients::addReaderEntry(StoreEntry &e, const cache_key *key) | |
272 | { | |
273 | sfileno index = 0; | |
274 | const auto anchor = map->openOrCreateForReading(key, index, e); | |
275 | if (!anchor) | |
276 | throw TextException("reader collision", Here()); | |
277 | ||
278 | anchorEntry(e, index, *anchor); | |
279 | // keep the entry locked (for reading) to receive remote DELETE events | |
280 | } | |
281 | ||
282 | /// fills (recently created) StoreEntry with information currently in Transients | |
283 | void | |
284 | Transients::anchorEntry(StoreEntry &e, const sfileno index, const Ipc::StoreMapAnchor &anchor) | |
285 | { | |
286 | // set ASAP in hope to unlock the slot if something throws | |
287 | // and to provide index to such methods as hasWriter() | |
288 | auto &xitTable = e.mem_obj->xitTable; | |
289 | xitTable.index = index; | |
290 | xitTable.io = Store::ioReading; | |
291 | ||
292 | const auto hadWriter = hasWriter(e); // before computing collapsingRequired | |
293 | anchor.exportInto(e); | |
294 | const bool collapsingRequired = EBIT_TEST(anchor.basics.flags, ENTRY_REQUIRES_COLLAPSING); | |
295 | assert(!collapsingRequired || hadWriter); | |
296 | e.setCollapsingRequirement(collapsingRequired); | |
9a9954ba AR |
297 | } |
298 | ||
d1d3b4dc EB |
299 | bool |
300 | Transients::hasWriter(const StoreEntry &e) | |
301 | { | |
302 | if (!e.hasTransients()) | |
303 | return false; | |
304 | return map->peekAtWriter(e.mem_obj->xitTable.index); | |
305 | } | |
306 | ||
9a9954ba | 307 | void |
ced8def3 | 308 | Transients::noteFreeMapSlice(const Ipc::StoreMapSliceId) |
9a9954ba AR |
309 | { |
310 | // TODO: we should probably find the entry being deleted and abort it | |
311 | } | |
312 | ||
4475555f | 313 | void |
d2a6dcba | 314 | Transients::status(const StoreEntry &entry, Transients::EntryStatus &entryStatus) const |
4475555f AR |
315 | { |
316 | assert(map); | |
4310f8b0 EB |
317 | assert(entry.hasTransients()); |
318 | const auto idx = entry.mem_obj->xitTable.index; | |
319 | const auto &anchor = isWriter(entry) ? | |
320 | map->writeableEntry(idx) : map->readableEntry(idx); | |
d2a6dcba EB |
321 | entryStatus.abortedByWriter = anchor.writerHalted; |
322 | entryStatus.waitingToBeFreed = anchor.waitingToBeFreed; | |
323 | entryStatus.collapsed = EBIT_TEST(anchor.basics.flags, ENTRY_REQUIRES_COLLAPSING); | |
4475555f AR |
324 | } |
325 | ||
99921d9d AR |
326 | void |
327 | Transients::completeWriting(const StoreEntry &e) | |
328 | { | |
4310f8b0 EB |
329 | assert(e.hasTransients()); |
330 | assert(isWriter(e)); | |
8253d451 | 331 | map->switchWritingToReading(e.mem_obj->xitTable.index); |
4310f8b0 | 332 | e.mem_obj->xitTable.io = Store::ioReading; |
99921d9d AR |
333 | } |
334 | ||
d366a7fa AR |
335 | int |
336 | Transients::readers(const StoreEntry &e) const | |
337 | { | |
4310f8b0 | 338 | if (e.hasTransients()) { |
d366a7fa AR |
339 | assert(map); |
340 | return map->peekAtEntry(e.mem_obj->xitTable.index).lock.readers; | |
341 | } | |
342 | return 0; | |
343 | } | |
344 | ||
1bfe9ade | 345 | void |
4310f8b0 EB |
346 | Transients::evictCached(StoreEntry &e) |
347 | { | |
348 | debugs(20, 5, e); | |
349 | if (e.hasTransients()) { | |
350 | const auto index = e.mem_obj->xitTable.index; | |
351 | if (map->freeEntry(index)) { | |
352 | // Delay syncCollapsed(index) which may end `e` wait for updates. | |
353 | // Calling it directly/here creates complex reentrant call chains. | |
354 | CollapsedForwarding::Broadcast(e, true); | |
355 | } | |
356 | } // else nothing to do because e must be private | |
2745fea5 AR |
357 | } |
358 | ||
359 | void | |
4310f8b0 | 360 | Transients::evictIfFound(const cache_key *key) |
1bfe9ade | 361 | { |
4310f8b0 EB |
362 | if (!map) |
363 | return; | |
364 | ||
365 | const sfileno index = map->fileNoByKey(key); | |
366 | if (map->freeEntry(index)) | |
367 | CollapsedForwarding::Broadcast(index, true); | |
1bfe9ade AR |
368 | } |
369 | ||
4475555f | 370 | void |
4310f8b0 | 371 | Transients::disconnect(StoreEntry &entry) |
4475555f | 372 | { |
4310f8b0 EB |
373 | debugs(20, 5, entry); |
374 | if (entry.hasTransients()) { | |
375 | auto &xitTable = entry.mem_obj->xitTable; | |
99921d9d | 376 | assert(map); |
4310f8b0 EB |
377 | if (isWriter(entry)) { |
378 | map->abortWriting(xitTable.index); | |
99921d9d | 379 | } else { |
4310f8b0 | 380 | assert(isReader(entry)); |
d1d3b4dc | 381 | map->closeForReadingAndFreeIdle(xitTable.index); |
99921d9d | 382 | } |
4310f8b0 EB |
383 | locals->at(xitTable.index) = nullptr; |
384 | xitTable.index = -1; | |
385 | xitTable.io = Store::ioDone; | |
99921d9d | 386 | } |
4475555f AR |
387 | } |
388 | ||
9a9954ba AR |
389 | /// calculates maximum number of entries we need to store and map |
390 | int64_t | |
391 | Transients::EntryLimit() | |
392 | { | |
daed75a9 EB |
393 | return (UsingSmp() && Store::Controller::SmpAware()) ? |
394 | Config.shared_transient_entries_limit : 0; | |
9a9954ba AR |
395 | } |
396 | ||
4310f8b0 EB |
397 | bool |
398 | Transients::markedForDeletion(const cache_key *key) const | |
399 | { | |
400 | assert(map); | |
401 | return map->markedForDeletion(key); | |
402 | } | |
403 | ||
404 | bool | |
405 | Transients::isReader(const StoreEntry &e) const | |
406 | { | |
407 | return e.mem_obj && e.mem_obj->xitTable.io == Store::ioReading; | |
408 | } | |
409 | ||
410 | bool | |
411 | Transients::isWriter(const StoreEntry &e) const | |
412 | { | |
413 | return e.mem_obj && e.mem_obj->xitTable.io == Store::ioWriting; | |
414 | } | |
415 | ||
9a9954ba AR |
416 | /// initializes shared memory segment used by Transients |
417 | class TransientsRr: public Ipc::Mem::RegisteredRunner | |
418 | { | |
419 | public: | |
420 | /* RegisteredRunner API */ | |
21b7990f | 421 | virtual void useConfig(); |
9a9954ba AR |
422 | virtual ~TransientsRr(); |
423 | ||
424 | protected: | |
21b7990f | 425 | virtual void create(); |
9a9954ba AR |
426 | |
427 | private: | |
4310f8b0 | 428 | TransientsMap::Owner *mapOwner = nullptr; |
9a9954ba AR |
429 | }; |
430 | ||
21b7990f | 431 | RunnerRegistrationEntry(TransientsRr); |
9a9954ba | 432 | |
e4d13993 | 433 | void |
21b7990f | 434 | TransientsRr::useConfig() |
9a9954ba AR |
435 | { |
436 | assert(Config.memShared.configured()); | |
21b7990f | 437 | Ipc::Mem::RegisteredRunner::useConfig(); |
9a9954ba AR |
438 | } |
439 | ||
e4d13993 | 440 | void |
21b7990f | 441 | TransientsRr::create() |
9a9954ba | 442 | { |
9a9954ba | 443 | const int64_t entryLimit = Transients::EntryLimit(); |
9a9954ba AR |
444 | if (entryLimit <= 0) |
445 | return; // no SMP configured or a misconfiguration | |
446 | ||
447 | Must(!mapOwner); | |
448 | mapOwner = TransientsMap::Init(MapLabel, entryLimit); | |
449 | } | |
450 | ||
451 | TransientsRr::~TransientsRr() | |
452 | { | |
453 | delete mapOwner; | |
454 | } | |
f53969cc | 455 |