/**********************************************************************************[ClausesBuffer.cc] Glucose -- Copyright (c) 2009-2014, Gilles Audemard, Laurent Simon CRIL - Univ. Artois, France LRI - Univ. Paris Sud, France (2009-2013) Labri - Univ. Bordeaux, France Syrup (Glucose Parallel) -- Copyright (c) 2013-2014, Gilles Audemard, Laurent Simon CRIL - Univ. Artois, France Labri - Univ. Bordeaux, France Glucose sources are based on MiniSat (see below MiniSat copyrights). Permissions and copyrights of Glucose (sources until 2013, Glucose 3.0, single core) are exactly the same as Minisat on which it is based on. (see below). Glucose-Syrup sources are based on another copyright. Permissions and copyrights for the parallel version of Glucose-Syrup (the "Software") are granted, free of charge, to deal with the Software without restriction, including the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: - The above and below copyrights notices and this permission notice shall be included in all copies or substantial portions of the Software; - The parallel version of Glucose (all files modified since Glucose 3.0 releases, 2013) cannot be used in any competitive event (sat competitions/evaluations) without the express permission of the authors (Gilles Audemard / Laurent Simon). This is also the case for any competitive event using Glucose Parallel as an embedded SAT engine (single core or not). --------------- Original Minisat Copyrights Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson Copyright (c) 2007-2010, Niklas Sorensson Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. **************************************************************************************************/ /* ClausesBuffer * * This class is responsible for exchanging clauses between threads. * It is based on a fixed-length FIFO array of literals. * If the FIFO is full, then old clauses are removed (even if it was not yet sent to all threads) * * a clause " l1 l2 l3" is pushed in the FIFO with the following 6 unsigned integers * 3 nseen origin l1 l2 l3 * + 3 is the size of the pushed clause * + nseen is the number of thread which imported this clause (initialized with nthreads-1) * (when set to 0, the clause is removed from the fifo) * + origin is the thread id of the thread which added this clause to the fifo * + l1 l2 l3 are the literals of the clause * * ********************************************************************************************** * **CAREFUL** This class is not thread-safe. In glucose-syrup, the SharedCompanion is * responsible for ensuring atomicity of main functions * ********************************************************************************************** * * */ #include "parallel/ClausesBuffer.h" //================================================================================================= using namespace Glucose; extern BoolOption opt_whenFullRemoveOlder; extern IntOption opt_fifoSizeByCore; // index : size clause // index + 1 : nbSeen // index + 2 : threadId // index + 3 : .. index + 3 + size : Lit of clause ClausesBuffer::ClausesBuffer(int _nbThreads, unsigned int _maxsize) : first(0), last(_maxsize-1), maxsize(_maxsize), queuesize(0), removedClauses(0), forcedRemovedClauses(0), nbThreads(_nbThreads), whenFullRemoveOlder(opt_whenFullRemoveOlder), fifoSizeByCore(opt_fifoSizeByCore) { lastOfThread.growTo(_nbThreads); for(int i=0;i= maxsize) return i - maxsize; return i; } void ClausesBuffer::removeLastClause() { assert(queuesize > 0); do { unsigned int size = (unsigned int) elems[nextIndex(last)]; unsigned int nextlast = addIndex(last, size+headerSize); for(int i=0;i 0); queuesize --; } removedClauses ++; assert(last >= 0); assert(last < maxsize); assert(last == nextlast); } while (queuesize > 0 && (elems[addIndex(last,2)] == 0)); } // Pushes a single uint to the fifo inline void ClausesBuffer::noCheckPush(uint32_t x) { elems[first] = x; first = nextIndex(first); } // Pops a single uint from the fifo inline uint32_t ClausesBuffer::noCheckPop(uint32_t & index) { index = nextIndex(index); uint32_t ret = elems[index]; return ret; } // Return true if the clause was succesfully added bool ClausesBuffer::pushClause(int threadId, Clause & c) { if (!whenFullRemoveOlder && (queuesize + c.size() + headerSize >= maxsize)) return false; // We need to remove some old clauses while (queuesize + c.size() + headerSize >= maxsize) { // We need to remove some old clauses forcedRemovedClauses ++; removeLastClause(); assert(queuesize > 0); } noCheckPush(c.size()); noCheckPush(nbThreads>1?nbThreads-1:1); noCheckPush(threadId); for(int i=0;i (%d, %d)\n", first, last); } bool ClausesBuffer::getClause(int threadId, int & threadOrigin, vec & resultClause, bool firstFound) { assert(lastOfThread.size() > threadId); unsigned int thislast = lastOfThread[threadId]; assert(!firstFound || thislast == last); // Early exiting if (nextIndex(thislast) == first) return false; if ( ( thislast < last && last < first) || ( first < thislast && thislast < last ) || ( last < first && first < thislast) ) { // Special case where last has moved and lastOfThread[threadId] is no more valid (is behind) thislast = last; } assert(!firstFound); // Go to next clause for this thread id if (!firstFound) { while (nextIndex(thislast) != first && elems[addIndex(thislast,3)] == ((unsigned int)threadId)) { // 3 = 2 + 1 thislast = addIndex(thislast, elems[nextIndex(thislast)] + headerSize); // assert(thislast >= 0); assert(thislast < maxsize); } assert(nextIndex(thislast)==first || elems[addIndex(thislast,3)] != (unsigned int)threadId); } if (nextIndex(thislast) == first) { lastOfThread[threadId] = thislast; return false; } assert(elems[addIndex(thislast,3)] != ((unsigned int) threadId)); unsigned int previouslast = thislast; bool removeAfter = false; int csize = noCheckPop(thislast); removeAfter = (--elems[addIndex(thislast,1)] == 0); // We are sure this is not one of our own clause thislast = nextIndex(thislast); // Skips the removeAfter fieldr threadOrigin = noCheckPop(thislast); assert(threadOrigin != threadId); resultClause.clear(); for(int i=0;i