dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2008, 2011 Free Software Foundation, Inc. |
| 3 | * |
| 4 | * This software is distributed under the terms of the GNU Affero Public License. |
| 5 | * See the COPYING file in the main directory for details. |
| 6 | * |
| 7 | * This use of this software may be subject to additional restrictions. |
| 8 | * See the LEGAL file in the main directory for details. |
| 9 | |
| 10 | This program is free software: you can redistribute it and/or modify |
| 11 | it under the terms of the GNU Affero General Public License as published by |
| 12 | the Free Software Foundation, either version 3 of the License, or |
| 13 | (at your option) any later version. |
| 14 | |
| 15 | This program is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | GNU Affero General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU Affero General Public License |
| 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 22 | |
| 23 | */ |
| 24 | |
| 25 | |
| 26 | #ifndef INTERTHREAD_H |
| 27 | #define INTERTHREAD_H |
| 28 | |
| 29 | #include "Timeval.h" |
| 30 | #include "Threads.h" |
| 31 | #include "LinkedLists.h" |
| 32 | #include <map> |
| 33 | #include <vector> |
| 34 | #include <queue> |
| 35 | |
| 36 | |
| 37 | |
| 38 | |
| 39 | |
| 40 | /**@defgroup Templates for interthread mechanisms. */ |
| 41 | //@{ |
| 42 | |
| 43 | |
| 44 | /** Pointer FIFO for interthread operations. */ |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 45 | // (pat) The elements in the queue are type T*, and |
| 46 | // the Fifo class implements the underlying queue. |
| 47 | // The default is class PointerFIFO, which does not place any restrictions on the type of T, |
| 48 | // and is implemented by allocating auxilliary structures for the queue, |
| 49 | // or SingleLinkedList, which implements the queue using an internal pointer in type T, |
| 50 | // which must implement the functional interface of class SingleLinkListNode, |
| 51 | // namely: functions T*next() and void setNext(T*). |
| 52 | template <class T, class Fifo=PointerFIFO> class InterthreadQueue { |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 53 | |
| 54 | protected: |
| 55 | |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 56 | Fifo mQ; |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 57 | mutable Mutex mLock; |
| 58 | mutable Signal mWriteSignal; |
| 59 | |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 60 | public: |
| 61 | |
| 62 | /** Delete contents. */ |
| 63 | void clear() |
| 64 | { |
| 65 | ScopedLock lock(mLock); |
| 66 | while (mQ.size()>0) delete (T*)mQ.get(); |
| 67 | } |
| 68 | |
| 69 | /** Empty the queue, but don't delete. */ |
| 70 | void flushNoDelete() |
| 71 | { |
| 72 | ScopedLock lock(mLock); |
| 73 | while (mQ.size()>0) mQ.get(); |
| 74 | } |
| 75 | |
| 76 | |
| 77 | ~InterthreadQueue() |
| 78 | { clear(); } |
| 79 | |
| 80 | |
| 81 | size_t size() const |
| 82 | { |
| 83 | ScopedLock lock(mLock); |
| 84 | return mQ.size(); |
| 85 | } |
| 86 | |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 87 | size_t totalSize() const // pat added |
| 88 | { |
| 89 | ScopedLock lock(mLock); |
| 90 | return mQ.totalSize(); |
| 91 | } |
| 92 | |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 93 | /** |
| 94 | Blocking read. |
| 95 | @return Pointer to object (will not be NULL). |
| 96 | */ |
| 97 | T* read() |
| 98 | { |
| 99 | ScopedLock lock(mLock); |
| 100 | T* retVal = (T*)mQ.get(); |
| 101 | while (retVal==NULL) { |
| 102 | mWriteSignal.wait(mLock); |
| 103 | retVal = (T*)mQ.get(); |
| 104 | } |
| 105 | return retVal; |
| 106 | } |
| 107 | |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 108 | /** Non-blocking peek at the first element; returns NULL if empty. */ |
| 109 | T* front() |
| 110 | { |
| 111 | ScopedLock lock(mLock); |
| 112 | return (T*) mQ.front(); |
| 113 | } |
| 114 | |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 115 | /** |
| 116 | Blocking read with a timeout. |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 117 | @param timeout The read timeout in ms. |
| 118 | @return Pointer to object or NULL on timeout. |
| 119 | */ |
| 120 | T* read(unsigned timeout) |
| 121 | { |
| 122 | if (timeout==0) return readNoBlock(); |
| 123 | Timeval waitTime(timeout); |
| 124 | ScopedLock lock(mLock); |
| 125 | while ((mQ.size()==0) && (!waitTime.passed())) |
| 126 | mWriteSignal.wait(mLock,waitTime.remaining()); |
| 127 | T* retVal = (T*)mQ.get(); |
| 128 | return retVal; |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | Non-blocking read. |
| 133 | @return Pointer to object or NULL if FIFO is empty. |
| 134 | */ |
| 135 | T* readNoBlock() |
| 136 | { |
| 137 | ScopedLock lock(mLock); |
| 138 | return (T*)mQ.get(); |
| 139 | } |
| 140 | |
| 141 | /** Non-blocking write. */ |
| 142 | void write(T* val) |
| 143 | { |
| 144 | ScopedLock lock(mLock); |
| 145 | mQ.put(val); |
| 146 | mWriteSignal.signal(); |
| 147 | } |
| 148 | |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 149 | /** Non-block write to the front of the queue. */ |
| 150 | void write_front(T* val) // pat added |
| 151 | { |
| 152 | ScopedLock lock(mLock); |
| 153 | mQ.push_front(val); |
| 154 | mWriteSignal.signal(); |
| 155 | } |
| 156 | }; |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 157 | |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 158 | // (pat) Identical to above but with the threading problem fixed. |
| 159 | template <class T, class Fifo=PointerFIFO> class InterthreadQueue2 { |
| 160 | |
| 161 | protected: |
| 162 | |
| 163 | Fifo mQ; |
| 164 | mutable Mutex mLock; |
| 165 | mutable Signal mWriteSignal; |
| 166 | |
| 167 | public: |
| 168 | |
| 169 | /** Delete contents. */ |
| 170 | void clear() |
| 171 | { |
| 172 | ScopedLock lock(mLock); |
| 173 | while (mQ.size()>0) delete (T*)mQ.get(); |
| 174 | } |
| 175 | |
| 176 | /** Empty the queue, but don't delete. */ |
| 177 | void flushNoDelete() |
| 178 | { |
| 179 | ScopedLock lock(mLock); |
| 180 | while (mQ.size()>0) mQ.get(); |
| 181 | } |
| 182 | |
| 183 | |
| 184 | ~InterthreadQueue2() |
| 185 | { clear(); } |
| 186 | |
| 187 | |
| 188 | size_t size() const |
| 189 | { |
| 190 | ScopedLock lock(mLock); |
| 191 | return mQ.size(); |
| 192 | } |
| 193 | |
| 194 | size_t totalSize() const // pat added |
| 195 | { |
| 196 | ScopedLock lock(mLock); |
| 197 | return mQ.totalSize(); |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | Blocking read. |
| 202 | @return Pointer to object (will not be NULL). |
| 203 | */ |
| 204 | T* read() |
| 205 | { |
| 206 | ScopedLock lock(mLock); |
| 207 | T* retVal = (T*)mQ.get(); |
| 208 | while (retVal==NULL) { |
| 209 | mWriteSignal.wait(mLock); |
| 210 | retVal = (T*)mQ.get(); |
| 211 | } |
| 212 | return retVal; |
| 213 | } |
| 214 | |
| 215 | /** Non-blocking peek at the first element; returns NULL if empty. */ |
| 216 | T* front() |
| 217 | { |
| 218 | ScopedLock lock(mLock); |
| 219 | return (T*) mQ.front(); |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | Blocking read with a timeout. |
| 224 | @param timeout The read timeout in ms. |
| 225 | @return Pointer to object or NULL on timeout. |
| 226 | */ |
| 227 | T* read(unsigned timeout) |
| 228 | { |
| 229 | if (timeout==0) return readNoBlock(); |
| 230 | Timeval waitTime(timeout); |
| 231 | ScopedLock lock(mLock); |
| 232 | while ((mQ.size()==0) && (!waitTime.passed())) |
| 233 | mWriteSignal.wait(mLock,waitTime.remaining()); |
| 234 | T* retVal = (T*)mQ.get(); |
| 235 | return retVal; |
| 236 | } |
| 237 | |
| 238 | /** |
| 239 | Non-blocking read. |
| 240 | @return Pointer to object or NULL if FIFO is empty. |
| 241 | */ |
| 242 | T* readNoBlock() |
| 243 | { |
| 244 | ScopedLock lock(mLock); |
| 245 | return (T*)mQ.get(); |
| 246 | } |
| 247 | |
| 248 | /** Non-blocking write. */ |
| 249 | void write(T* val) |
| 250 | { |
| 251 | // (pat) The Mutex mLock must be released before signaling the mWriteSignal condition. |
| 252 | // This is an implicit requirement of pthread_cond_wait() called from signal(). |
| 253 | // If you do not do that, the InterthreadQueue read() function cannot start |
| 254 | // because the mutex is still locked by the thread calling the write(), |
| 255 | // so the read() thread yields its immediate execution opportunity. |
| 256 | // This recurs (and the InterthreadQueue fills up with data) |
| 257 | // until the read thread's accumulated temporary priority causes it to |
| 258 | // get a second pre-emptive activation over the writing thread, |
| 259 | // resulting in bursts of activity by the read thread. |
| 260 | { ScopedLock lock(mLock); |
| 261 | mQ.put(val); |
| 262 | } |
| 263 | mWriteSignal.signal(); |
| 264 | } |
| 265 | |
| 266 | /** Non-block write to the front of the queue. */ |
| 267 | void write_front(T* val) // pat added |
| 268 | { |
| 269 | // (pat) See comments above. |
| 270 | { ScopedLock lock(mLock); |
| 271 | mQ.push_front(val); |
| 272 | } |
| 273 | mWriteSignal.signal(); |
| 274 | } |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 275 | }; |
| 276 | |
| 277 | |
| 278 | |
| 279 | /** Pointer FIFO for interthread operations. */ |
| 280 | template <class T> class InterthreadQueueWithWait { |
| 281 | |
| 282 | protected: |
| 283 | |
| 284 | PointerFIFO mQ; |
| 285 | mutable Mutex mLock; |
| 286 | mutable Signal mWriteSignal; |
| 287 | mutable Signal mReadSignal; |
| 288 | |
| 289 | virtual void freeElement(T* element) const { delete element; }; |
| 290 | |
| 291 | public: |
| 292 | |
| 293 | /** Delete contents. */ |
| 294 | void clear() |
| 295 | { |
| 296 | ScopedLock lock(mLock); |
| 297 | while (mQ.size()>0) freeElement((T*)mQ.get()); |
| 298 | mReadSignal.signal(); |
| 299 | } |
| 300 | |
| 301 | |
| 302 | |
| 303 | virtual ~InterthreadQueueWithWait() |
| 304 | { clear(); } |
| 305 | |
| 306 | |
| 307 | size_t size() const |
| 308 | { |
| 309 | ScopedLock lock(mLock); |
| 310 | return mQ.size(); |
| 311 | } |
| 312 | |
| 313 | /** |
| 314 | Blocking read. |
| 315 | @return Pointer to object (will not be NULL). |
| 316 | */ |
| 317 | T* read() |
| 318 | { |
| 319 | ScopedLock lock(mLock); |
| 320 | T* retVal = (T*)mQ.get(); |
| 321 | while (retVal==NULL) { |
| 322 | mWriteSignal.wait(mLock); |
| 323 | retVal = (T*)mQ.get(); |
| 324 | } |
| 325 | mReadSignal.signal(); |
| 326 | return retVal; |
| 327 | } |
| 328 | |
| 329 | /** |
| 330 | Blocking read with a timeout. |
| 331 | @param timeout The read timeout in ms. |
| 332 | @return Pointer to object or NULL on timeout. |
| 333 | */ |
| 334 | T* read(unsigned timeout) |
| 335 | { |
| 336 | if (timeout==0) return readNoBlock(); |
| 337 | Timeval waitTime(timeout); |
| 338 | ScopedLock lock(mLock); |
| 339 | while ((mQ.size()==0) && (!waitTime.passed())) |
| 340 | mWriteSignal.wait(mLock,waitTime.remaining()); |
| 341 | T* retVal = (T*)mQ.get(); |
| 342 | if (retVal!=NULL) mReadSignal.signal(); |
| 343 | return retVal; |
| 344 | } |
| 345 | |
| 346 | /** |
| 347 | Non-blocking read. |
| 348 | @return Pointer to object or NULL if FIFO is empty. |
| 349 | */ |
| 350 | T* readNoBlock() |
| 351 | { |
| 352 | ScopedLock lock(mLock); |
| 353 | T* retVal = (T*)mQ.get(); |
| 354 | if (retVal!=NULL) mReadSignal.signal(); |
| 355 | return retVal; |
| 356 | } |
| 357 | |
| 358 | /** Non-blocking write. */ |
| 359 | void write(T* val) |
| 360 | { |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 361 | // (pat) 8-14: Taking out the threading problem fix temporarily for David to use in the field. |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 362 | ScopedLock lock(mLock); |
| 363 | mQ.put(val); |
| 364 | mWriteSignal.signal(); |
| 365 | } |
| 366 | |
| 367 | /** Wait until the queue falls below a low water mark. */ |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 368 | // (pat) This function suffers from the same problem as documented |
| 369 | // at InterthreadQueue.write(), but I am not fixing it because I cannot test it. |
| 370 | // The caller of this function will eventually get to run, just not immediately |
| 371 | // after the mReadSignal condition is fulfilled. |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 372 | void wait(size_t sz=0) |
| 373 | { |
| 374 | ScopedLock lock(mLock); |
| 375 | while (mQ.size()>sz) mReadSignal.wait(mLock); |
| 376 | } |
| 377 | |
| 378 | }; |
| 379 | |
| 380 | |
| 381 | |
| 382 | |
| 383 | |
| 384 | /** Thread-safe map of pointers to class D, keyed by class K. */ |
| 385 | template <class K, class D > class InterthreadMap { |
| 386 | |
| 387 | protected: |
| 388 | |
| 389 | typedef std::map<K,D*> Map; |
| 390 | Map mMap; |
| 391 | mutable Mutex mLock; |
| 392 | Signal mWriteSignal; |
| 393 | |
| 394 | public: |
| 395 | |
| 396 | void clear() |
| 397 | { |
| 398 | // Delete everything in the map. |
| 399 | ScopedLock lock(mLock); |
| 400 | typename Map::iterator iter = mMap.begin(); |
| 401 | while (iter != mMap.end()) { |
| 402 | delete iter->second; |
| 403 | ++iter; |
| 404 | } |
| 405 | mMap.clear(); |
| 406 | } |
| 407 | |
| 408 | ~InterthreadMap() { clear(); } |
| 409 | |
| 410 | /** |
| 411 | Non-blocking write. |
| 412 | @param key The index to write to. |
| 413 | @param wData Pointer to data, not to be deleted until removed from the map. |
| 414 | */ |
| 415 | void write(const K &key, D * wData) |
| 416 | { |
| 417 | ScopedLock lock(mLock); |
| 418 | typename Map::iterator iter = mMap.find(key); |
| 419 | if (iter!=mMap.end()) { |
| 420 | delete iter->second; |
| 421 | iter->second = wData; |
| 422 | } else { |
| 423 | mMap[key] = wData; |
| 424 | } |
| 425 | mWriteSignal.broadcast(); |
| 426 | } |
| 427 | |
| 428 | /** |
| 429 | Non-blocking read with element removal. |
| 430 | @param key Key to read from. |
| 431 | @return Pointer at key or NULL if key not found, to be deleted by caller. |
| 432 | */ |
| 433 | D* getNoBlock(const K& key) |
| 434 | { |
| 435 | ScopedLock lock(mLock); |
| 436 | typename Map::iterator iter = mMap.find(key); |
| 437 | if (iter==mMap.end()) return NULL; |
| 438 | D* retVal = iter->second; |
| 439 | mMap.erase(iter); |
| 440 | return retVal; |
| 441 | } |
| 442 | |
| 443 | /** |
| 444 | Blocking read with a timeout and element removal. |
| 445 | @param key The key to read from. |
| 446 | @param timeout The blocking timeout in ms. |
| 447 | @return Pointer at key or NULL on timeout, to be deleted by caller. |
| 448 | */ |
| 449 | D* get(const K &key, unsigned timeout) |
| 450 | { |
| 451 | if (timeout==0) return getNoBlock(key); |
| 452 | Timeval waitTime(timeout); |
| 453 | ScopedLock lock(mLock); |
| 454 | typename Map::iterator iter = mMap.find(key); |
| 455 | while ((iter==mMap.end()) && (!waitTime.passed())) { |
| 456 | mWriteSignal.wait(mLock,waitTime.remaining()); |
| 457 | iter = mMap.find(key); |
| 458 | } |
| 459 | if (iter==mMap.end()) return NULL; |
| 460 | D* retVal = iter->second; |
| 461 | mMap.erase(iter); |
| 462 | return retVal; |
| 463 | } |
| 464 | |
| 465 | /** |
| 466 | Blocking read with and element removal. |
| 467 | @param key The key to read from. |
| 468 | @return Pointer at key, to be deleted by caller. |
| 469 | */ |
| 470 | D* get(const K &key) |
| 471 | { |
| 472 | ScopedLock lock(mLock); |
| 473 | typename Map::iterator iter = mMap.find(key); |
| 474 | while (iter==mMap.end()) { |
| 475 | mWriteSignal.wait(mLock); |
| 476 | iter = mMap.find(key); |
| 477 | } |
| 478 | D* retVal = iter->second; |
| 479 | mMap.erase(iter); |
| 480 | return retVal; |
| 481 | } |
| 482 | |
| 483 | |
| 484 | /** |
| 485 | Remove an entry and delete it. |
| 486 | @param key The key of the entry to delete. |
| 487 | @return True if it was actually found and deleted. |
| 488 | */ |
| 489 | bool remove(const K &key ) |
| 490 | { |
| 491 | D* val = getNoBlock(key); |
| 492 | if (!val) return false; |
| 493 | delete val; |
| 494 | return true; |
| 495 | } |
| 496 | |
| 497 | |
| 498 | /** |
| 499 | Non-blocking read. |
| 500 | @param key Key to read from. |
| 501 | @return Pointer at key or NULL if key not found. |
| 502 | */ |
| 503 | D* readNoBlock(const K& key) const |
| 504 | { |
| 505 | D* retVal=NULL; |
| 506 | ScopedLock lock(mLock); |
| 507 | typename Map::const_iterator iter = mMap.find(key); |
| 508 | if (iter!=mMap.end()) retVal = iter->second; |
| 509 | return retVal; |
| 510 | } |
| 511 | |
| 512 | /** |
| 513 | Blocking read with a timeout. |
| 514 | @param key The key to read from. |
| 515 | @param timeout The blocking timeout in ms. |
| 516 | @return Pointer at key or NULL on timeout. |
| 517 | */ |
| 518 | D* read(const K &key, unsigned timeout) const |
| 519 | { |
| 520 | if (timeout==0) return readNoBlock(key); |
| 521 | ScopedLock lock(mLock); |
| 522 | Timeval waitTime(timeout); |
| 523 | typename Map::const_iterator iter = mMap.find(key); |
| 524 | while ((iter==mMap.end()) && (!waitTime.passed())) { |
| 525 | mWriteSignal.wait(mLock,waitTime.remaining()); |
| 526 | iter = mMap.find(key); |
| 527 | } |
| 528 | if (iter==mMap.end()) return NULL; |
| 529 | D* retVal = iter->second; |
| 530 | return retVal; |
| 531 | } |
| 532 | |
| 533 | /** |
| 534 | Blocking read. |
| 535 | @param key The key to read from. |
| 536 | @return Pointer at key. |
| 537 | */ |
| 538 | D* read(const K &key) const |
| 539 | { |
| 540 | ScopedLock lock(mLock); |
| 541 | typename Map::const_iterator iter = mMap.find(key); |
| 542 | while (iter==mMap.end()) { |
| 543 | mWriteSignal.wait(mLock); |
| 544 | iter = mMap.find(key); |
| 545 | } |
| 546 | D* retVal = iter->second; |
| 547 | return retVal; |
| 548 | } |
| 549 | |
| 550 | }; |
| 551 | |
| 552 | |
| 553 | |
| 554 | |
| 555 | |
| 556 | |
| 557 | |
| 558 | /** This class is used to provide pointer-based comparison in priority_queues. */ |
| 559 | template <class T> class PointerCompare { |
| 560 | |
| 561 | public: |
| 562 | |
| 563 | /** Compare the objects pointed to, not the pointers themselves. */ |
| 564 | bool operator()(const T *v1, const T *v2) |
| 565 | { return (*v1)>(*v2); } |
| 566 | |
| 567 | }; |
| 568 | |
| 569 | |
| 570 | |
| 571 | /** |
| 572 | Priority queue for interthread operations. |
| 573 | Passes pointers to objects. |
| 574 | */ |
| 575 | template <class T, class C = std::vector<T*>, class Cmp = PointerCompare<T> > class InterthreadPriorityQueue { |
| 576 | |
| 577 | protected: |
| 578 | |
| 579 | std::priority_queue<T*,C,Cmp> mQ; |
| 580 | mutable Mutex mLock; |
| 581 | mutable Signal mWriteSignal; |
| 582 | |
| 583 | public: |
| 584 | |
| 585 | |
| 586 | /** Clear the FIFO. */ |
| 587 | void clear() |
| 588 | { |
| 589 | ScopedLock lock(mLock); |
| 590 | while (mQ.size()>0) { |
| 591 | T* ptr = mQ.top(); |
| 592 | mQ.pop(); |
| 593 | delete ptr; |
| 594 | } |
| 595 | } |
| 596 | |
| 597 | |
| 598 | ~InterthreadPriorityQueue() |
| 599 | { |
| 600 | clear(); |
| 601 | } |
| 602 | |
| 603 | size_t size() const |
| 604 | { |
| 605 | ScopedLock lock(mLock); |
| 606 | return mQ.size(); |
| 607 | } |
| 608 | |
| 609 | |
| 610 | /** Non-blocking read. */ |
| 611 | T* readNoBlock() |
| 612 | { |
| 613 | ScopedLock lock(mLock); |
| 614 | T* retVal = NULL; |
| 615 | if (mQ.size()!=0) { |
| 616 | retVal = mQ.top(); |
| 617 | mQ.pop(); |
| 618 | } |
| 619 | return retVal; |
| 620 | } |
| 621 | |
| 622 | /** Blocking read. */ |
| 623 | T* read() |
| 624 | { |
| 625 | ScopedLock lock(mLock); |
| 626 | T* retVal; |
| 627 | while (mQ.size()==0) mWriteSignal.wait(mLock); |
| 628 | retVal = mQ.top(); |
| 629 | mQ.pop(); |
| 630 | return retVal; |
| 631 | } |
| 632 | |
| 633 | /** Non-blocking write. */ |
| 634 | void write(T* val) |
| 635 | { |
kurtis.heimerl | 5a87247 | 2013-05-31 21:47:25 +0000 | [diff] [blame] | 636 | // (pat) 8-14: Taking out the threading problem fix temporarily for David to use in the field. |
dburgess | 82c46ff | 2011-10-07 02:40:51 +0000 | [diff] [blame] | 637 | ScopedLock lock(mLock); |
| 638 | mQ.push(val); |
| 639 | mWriteSignal.signal(); |
| 640 | } |
| 641 | |
| 642 | }; |
| 643 | |
| 644 | |
| 645 | |
| 646 | |
| 647 | |
| 648 | class Semaphore { |
| 649 | |
| 650 | private: |
| 651 | |
| 652 | bool mFlag; |
| 653 | Signal mSignal; |
| 654 | mutable Mutex mLock; |
| 655 | |
| 656 | public: |
| 657 | |
| 658 | Semaphore() |
| 659 | :mFlag(false) |
| 660 | { } |
| 661 | |
| 662 | void post() |
| 663 | { |
| 664 | ScopedLock lock(mLock); |
| 665 | mFlag=true; |
| 666 | mSignal.signal(); |
| 667 | } |
| 668 | |
| 669 | void get() |
| 670 | { |
| 671 | ScopedLock lock(mLock); |
| 672 | while (!mFlag) mSignal.wait(mLock); |
| 673 | mFlag=false; |
| 674 | } |
| 675 | |
| 676 | bool semtry() |
| 677 | { |
| 678 | ScopedLock lock(mLock); |
| 679 | bool retVal = mFlag; |
| 680 | mFlag = false; |
| 681 | return retVal; |
| 682 | } |
| 683 | |
| 684 | }; |
| 685 | |
| 686 | |
| 687 | |
| 688 | |
| 689 | |
| 690 | //@} |
| 691 | |
| 692 | |
| 693 | |
| 694 | |
| 695 | #endif |
| 696 | // vim: ts=4 sw=4 |