X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=cyclegraph.cc;h=f4590bfb6fa1cd44b41efdd91157ddcdfa812d78;hp=b13837293c665e9eacc4a4440e91631770c22347;hb=89ecd60fab0d93d6df6aa35e663ab67db860fa1d;hpb=58a4edbf1f1eba39ebe6386df49ea6ff7655a206 diff --git a/cyclegraph.cc b/cyclegraph.cc index b1383729..f4590bfb 100644 --- a/cyclegraph.cc +++ b/cyclegraph.cc @@ -1,12 +1,12 @@ #include "cyclegraph.h" #include "action.h" #include "common.h" -#include "promise.h" -#include "model.h" +#include "threads-model.h" /** Initializes a CycleGraph object. */ CycleGraph::CycleGraph() : discovered(new HashTable(16)), + queue(new ModelVector()), hasCycles(false), oldCycles(false) { @@ -15,6 +15,7 @@ CycleGraph::CycleGraph() : /** CycleGraph destructor */ CycleGraph::~CycleGraph() { + delete queue; delete discovered; } @@ -31,39 +32,12 @@ void CycleGraph::putNode(const ModelAction *act, CycleNode *node) #endif } -/** - * Add a CycleNode to the graph, corresponding to a Promise - * @param promise The Promise that should be added - * @param node The CycleNode that corresponds to the Promise - */ -void CycleGraph::putNode(const Promise *promise, CycleNode *node) -{ - const ModelAction *reader = promise->get_action(); - readerToPromiseNode.put(reader, node); -} - -/** - * @brief Remove the Promise node from the graph - * @param promise The promise to remove from the graph - */ -void CycleGraph::erasePromiseNode(const Promise *promise) -{ - const ModelAction *reader = promise->get_action(); - readerToPromiseNode.put(reader, NULL); -} - /** @return The corresponding CycleNode, if exists; otherwise NULL */ CycleNode * CycleGraph::getNode_noCreate(const ModelAction *act) const { return actionToNode.get(act); } -/** @return The corresponding CycleNode, if exists; otherwise NULL */ -CycleNode * CycleGraph::getNode_noCreate(const Promise *promise) const -{ - return readerToPromiseNode.get(promise->get_action()); -} - /** * @brief Returns the CycleNode corresponding to a given ModelAction * @@ -82,113 +56,6 @@ CycleNode * CycleGraph::getNode(const ModelAction *action) return node; } -/** - * @brief Returns a CycleNode corresponding to a promise - * - * Gets (or creates, if none exist) a CycleNode corresponding to a promised - * value. - * - * @param promise The Promise generated by a reader - * @return The CycleNode corresponding to the Promise - */ -CycleNode * CycleGraph::getNode(const Promise *promise) -{ - CycleNode *node = getNode_noCreate(promise); - if (node == NULL) { - node = new CycleNode(promise); - putNode(promise, node); - } - return node; -} - -/** - * @return false if the resolution results in a cycle; true otherwise - */ -bool CycleGraph::resolvePromise(ModelAction *reader, ModelAction *writer, - promise_list_t *mustResolve) -{ - CycleNode *promise_node = readerToPromiseNode.get(reader); - CycleNode *w_node = actionToNode.get(writer); - ASSERT(promise_node); - - if (w_node) - return mergeNodes(w_node, promise_node, mustResolve); - /* No existing write-node; just convert the promise-node */ - promise_node->resolvePromise(writer); - erasePromiseNode(promise_node->getPromise()); - putNode(writer, promise_node); - return true; -} - -/** - * @brief Merge two CycleNodes that represent the same write - * - * Note that this operation cannot be rolled back. - * - * @param w_node The write ModelAction node with which to merge - * @param p_node The Promise node to merge. Will be destroyed after this - * function. - * @param mustMerge Return (pass-by-reference) any additional Promises that - * must also be merged with w_node - * - * @return false if the merge results in a cycle; true otherwise - */ -bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node, - promise_list_t *mustMerge) -{ - ASSERT(!w_node->is_promise()); - ASSERT(p_node->is_promise()); - - const Promise *promise = p_node->getPromise(); - if (!promise->is_compatible(w_node->getAction())) { - hasCycles = true; - return false; - } - - /* Transfer the RMW */ - CycleNode *promise_rmw = p_node->getRMW(); - if (promise_rmw && promise_rmw != w_node->getRMW() && w_node->setRMW(promise_rmw)) - hasCycles = true; - - /* Transfer back edges to w_node */ - while (p_node->getNumBackEdges() > 0) { - CycleNode *back = p_node->removeBackEdge(); - if (back == w_node) - continue; - if (back->is_promise()) { - if (checkReachable(w_node, back)) { - /* Edge would create cycle; merge instead */ - mustMerge->push_back(back->getPromise()); - if (!mergeNodes(w_node, back, mustMerge)) - return false; - } else - back->addEdge(w_node); - } else - addNodeEdge(back, w_node); - } - - /* Transfer forward edges to w_node */ - while (p_node->getNumEdges() > 0) { - CycleNode *forward = p_node->removeEdge(); - if (forward == w_node) - continue; - if (forward->is_promise()) { - if (checkReachable(forward, w_node)) { - mustMerge->push_back(forward->getPromise()); - if (!mergeNodes(w_node, forward, mustMerge)) - return false; - } else - w_node->addEdge(forward); - } else - addNodeEdge(w_node, forward); - } - - erasePromiseNode(promise); - delete p_node; - - return !hasCycles; -} - /** * Adds an edge between two CycleNodes. * @param fromnode The edge comes from this CycleNode @@ -197,29 +64,33 @@ bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node, */ bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode) { - bool added; - - if (!hasCycles) - hasCycles = checkReachable(tonode, fromnode); - - if ((added = fromnode->addEdge(tonode))) + if (fromnode->addEdge(tonode)) { rollbackvector.push_back(fromnode); + if (!hasCycles) + hasCycles = checkReachable(tonode, fromnode); + } else + return false; /* No new edge */ /* - * If the fromnode has a rmwnode that is not the tonode, we should add - * an edge between its rmwnode and the tonode + * If the fromnode has a rmwnode that is not the tonode, we should + * follow its RMW chain to add an edge at the end, unless we encounter + * tonode along the way */ CycleNode *rmwnode = fromnode->getRMW(); - if (rmwnode && rmwnode != tonode) { - if (!hasCycles) - hasCycles = checkReachable(tonode, rmwnode); + if (rmwnode) { + while (rmwnode != tonode && rmwnode->getRMW()) + rmwnode = rmwnode->getRMW(); - if (rmwnode->addEdge(tonode)) { - rollbackvector.push_back(rmwnode); - added = true; + if (rmwnode != tonode) { + if (rmwnode->addEdge(tonode)) { + if (!hasCycles) + hasCycles = checkReachable(tonode, rmwnode); + + rollbackvector.push_back(rmwnode); + } } } - return added; + return true; } /** @@ -227,8 +98,8 @@ bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode) * * Handles special case of a RMW action, where the ModelAction rmw reads from * the ModelAction/Promise from. The key differences are: - * (1) no write can occur in between the rmw and the from action. - * (2) Only one RMW action can read from a given write. + * -# No write can occur in between the @a rmw and @a from actions. + * -# Only one RMW action can read from a given write. * * @param from The edge comes from this ModelAction/Promise * @param rmw The edge points to this ModelAction; this action must read from @@ -243,6 +114,9 @@ void CycleGraph::addRMWEdge(const T *from, const ModelAction *rmw) CycleNode *fromnode = getNode(from); CycleNode *rmwnode = getNode(rmw); + /* We assume that this RMW has no RMW reading from it yet */ + ASSERT(!rmwnode->getRMW()); + /* Two RMW actions cannot read from the same write. */ if (fromnode->setRMW(rmwnode)) hasCycles = true; @@ -256,7 +130,7 @@ void CycleGraph::addRMWEdge(const T *from, const ModelAction *rmw) * (2) the fromnode is the new node and therefore it should not * have any outgoing edges. */ - for (unsigned int i = 0; i < fromnode->getNumEdges(); i++) { + for (unsigned int i = 0;i < fromnode->getNumEdges();i++) { CycleNode *tonode = fromnode->getEdge(i); if (tonode != rmwnode) { if (rmwnode->addEdge(tonode)) @@ -268,7 +142,6 @@ void CycleGraph::addRMWEdge(const T *from, const ModelAction *rmw) } /* Instantiate two forms of CycleGraph::addRMWEdge */ template void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw); -template void CycleGraph::addRMWEdge(const Promise *from, const ModelAction *rmw); /** * @brief Adds an edge between objects @@ -294,26 +167,56 @@ bool CycleGraph::addEdge(const T *from, const U *to) return addNodeEdge(fromnode, tonode); } -/* Instantiate three forms of CycleGraph::addEdge */ +/* Instantiate four forms of CycleGraph::addEdge */ template bool CycleGraph::addEdge(const ModelAction *from, const ModelAction *to); -template bool CycleGraph::addEdge(const ModelAction *from, const Promise *to); -template bool CycleGraph::addEdge(const Promise *from, const ModelAction *to); #if SUPPORT_MOD_ORDER_DUMP + +static void print_node(FILE *file, const CycleNode *node, int label) +{ + const ModelAction *act = node->getAction(); + modelclock_t idx = act->get_seq_number(); + fprintf(file, "N%u", idx); + if (label) + fprintf(file, " [label=\"N%u, T%u\"]", idx, act->get_tid()); +} + +static void print_edge(FILE *file, const CycleNode *from, const CycleNode *to, const char *prop) +{ + print_node(file, from, 0); + fprintf(file, " -> "); + print_node(file, to, 0); + if (prop && strlen(prop)) + fprintf(file, " [%s]", prop); + fprintf(file, ";\n"); +} + +void CycleGraph::dot_print_node(FILE *file, const ModelAction *act) +{ + print_node(file, getNode(act), 1); +} + +template +void CycleGraph::dot_print_edge(FILE *file, const T *from, const U *to, const char *prop) +{ + CycleNode *fromnode = getNode(from); + CycleNode *tonode = getNode(to); + + print_edge(file, fromnode, tonode, prop); +} +/* Instantiate two forms of CycleGraph::dot_print_edge */ +template void CycleGraph::dot_print_edge(FILE *file, const ModelAction *from, const ModelAction *to, const char *prop); + void CycleGraph::dumpNodes(FILE *file) const { - for (unsigned int i = 0; i < nodeList.size(); i++) { - CycleNode *cn = nodeList[i]; - const ModelAction *action = cn->getAction(); - fprintf(file, "N%u [label=\"%u, T%u\"];\n", action->get_seq_number(), action->get_seq_number(), action->get_tid()); - if (cn->getRMW() != NULL) { - fprintf(file, "N%u -> N%u[style=dotted];\n", action->get_seq_number(), cn->getRMW()->getAction()->get_seq_number()); - } - for (unsigned int j = 0; j < cn->getNumEdges(); j++) { - CycleNode *dst = cn->getEdge(j); - const ModelAction *dstaction = dst->getAction(); - fprintf(file, "N%u -> N%u;\n", action->get_seq_number(), dstaction->get_seq_number()); - } + for (unsigned int i = 0;i < nodeList.size();i++) { + CycleNode *n = nodeList[i]; + print_node(file, n, 1); + fprintf(file, ";\n"); + if (n->getRMW()) + print_edge(file, n, n->getRMW(), "style=dotted"); + for (unsigned int j = 0;j < n->getNumEdges();j++) + print_edge(file, n, n->getEdge(j), NULL); } } @@ -337,22 +240,20 @@ void CycleGraph::dumpGraphToFile(const char *filename) const */ bool CycleGraph::checkReachable(const CycleNode *from, const CycleNode *to) const { - std::vector< const CycleNode *, ModelAlloc > queue; discovered->reset(); - - queue.push_back(from); + queue->clear(); + queue->push_back(from); discovered->put(from, from); - while (!queue.empty()) { - const CycleNode *node = queue.back(); - queue.pop_back(); + while (!queue->empty()) { + const CycleNode *node = queue->back(); + queue->pop_back(); if (node == to) return true; - - for (unsigned int i = 0; i < node->getNumEdges(); i++) { + for (unsigned int i = 0;i < node->getNumEdges();i++) { CycleNode *next = node->getEdge(i); if (!discovered->contains(next)) { discovered->put(next, next); - queue.push_back(next); + queue->push_back(next); } } } @@ -360,13 +261,13 @@ bool CycleGraph::checkReachable(const CycleNode *from, const CycleNode *to) cons } /** - * Checks whether one ModelAction can reach another ModelAction/Promise - * @param from The ModelAction from which to begin exploration + * Checks whether one ModelAction/Promise can reach another ModelAction/Promise + * @param from The ModelAction or Promise from which to begin exploration * @param to The ModelAction or Promise to reach * @return True, @a from can reach @a to; otherwise, false */ -template -bool CycleGraph::checkReachable(const ModelAction *from, const T *to) const +template +bool CycleGraph::checkReachable(const T *from, const U *to) const { CycleNode *fromnode = getNode_noCreate(from); CycleNode *tonode = getNode_noCreate(to); @@ -376,40 +277,11 @@ bool CycleGraph::checkReachable(const ModelAction *from, const T *to) const return checkReachable(fromnode, tonode); } -/* Instantiate two forms of CycleGraph::checkReachable */ +/* Instantiate four forms of CycleGraph::checkReachable */ template bool CycleGraph::checkReachable(const ModelAction *from, - const ModelAction *to) const; -template bool CycleGraph::checkReachable(const ModelAction *from, - const Promise *to) const; - -/** @return True, if the promise has failed; false otherwise */ -bool CycleGraph::checkPromise(const ModelAction *fromact, Promise *promise) const -{ - std::vector< CycleNode *, ModelAlloc > queue; - discovered->reset(); - CycleNode *from = actionToNode.get(fromact); - - queue.push_back(from); - discovered->put(from, from); - while (!queue.empty()) { - CycleNode *node = queue.back(); - queue.pop_back(); - - if (!node->is_promise() && - promise->eliminate_thread(node->getAction()->get_tid())) - return true; - - for (unsigned int i = 0; i < node->getNumEdges(); i++) { - CycleNode *next = node->getEdge(i); - if (!discovered->contains(next)) { - discovered->put(next, next); - queue.push_back(next); - } - } - } - return false; -} + const ModelAction *to) const; +/** @brief Begin a new sequence of graph additions which can be rolled back */ void CycleGraph::startChanges() { ASSERT(rollbackvector.empty()); @@ -428,10 +300,10 @@ void CycleGraph::commitChanges() /** Rollback changes to the previous commit. */ void CycleGraph::rollbackChanges() { - for (unsigned int i = 0; i < rollbackvector.size(); i++) + for (unsigned int i = 0;i < rollbackvector.size();i++) rollbackvector[i]->removeEdge(); - for (unsigned int i = 0; i < rmwrollbackvector.size(); i++) + for (unsigned int i = 0;i < rmwrollbackvector.size();i++) rmwrollbackvector[i]->clearRMW(); hasCycles = oldCycles; @@ -451,25 +323,13 @@ bool CycleGraph::checkForCycles() const */ CycleNode::CycleNode(const ModelAction *act) : action(act), - promise(NULL), - hasRMW(NULL) -{ -} - -/** - * @brief Constructor for a Promise CycleNode - * @param promise The Promise which was generated - */ -CycleNode::CycleNode(const Promise *promise) : - action(NULL), - promise(promise), hasRMW(NULL) { } /** * @param i The index of the edge to return - * @returns The a CycleNode edge indexed by i + * @returns The CycleNode edge indexed by i */ CycleNode * CycleNode::getEdge(unsigned int i) const { @@ -482,11 +342,16 @@ unsigned int CycleNode::getNumEdges() const return edges.size(); } +/** + * @param i The index of the back edge to return + * @returns The CycleNode back-edge indexed by i + */ CycleNode * CycleNode::getBackEdge(unsigned int i) const { return back_edges[i]; } +/** @returns The number of edges entering this CycleNode */ unsigned int CycleNode::getNumBackEdges() const { return back_edges.size(); @@ -499,9 +364,9 @@ unsigned int CycleNode::getNumBackEdges() const * @return True if the element was found; false otherwise */ template -static bool vector_remove_node(std::vector >& v, const T n) +static bool vector_remove_node(SnapVector& v, const T n) { - for (unsigned int i = 0; i < v.size(); i++) { + for (unsigned int i = 0;i < v.size();i++) { if (v[i] == n) { v.erase(v.begin() + i); return true; @@ -547,7 +412,7 @@ CycleNode * CycleNode::removeBackEdge() */ bool CycleNode::addEdge(CycleNode *node) { - for (unsigned int i = 0; i < edges.size(); i++) + for (unsigned int i = 0;i < edges.size();i++) if (edges[i] == node) return false; edges.push_back(node); @@ -574,19 +439,3 @@ bool CycleNode::setRMW(CycleNode *node) hasRMW = node; return false; } - -/** - * Convert a Promise CycleNode into a concrete-valued CycleNode. Should only be - * used when there's no existing ModelAction CycleNode for this write. - * - * @param writer The ModelAction which wrote the future value represented by - * this CycleNode - */ -void CycleNode::resolvePromise(const ModelAction *writer) -{ - ASSERT(is_promise()); - ASSERT(promise->is_compatible(writer)); - action = writer; - promise = NULL; - ASSERT(!is_promise()); -}