X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=cyclegraph.cc;h=def51f9671e346251a4f108abe1c78c8d09a8bfe;hp=e0b221514f9bd88b0785839b44e2436921f9f4b8;hb=HEAD;hpb=a482ef2b49ff9bcae7a6898585409181bce3f02a diff --git a/cyclegraph.cc b/cyclegraph.cc index e0b2215..def51f9 100644 --- a/cyclegraph.cc +++ b/cyclegraph.cc @@ -2,11 +2,12 @@ #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 +16,7 @@ CycleGraph::CycleGraph() : /** CycleGraph destructor */ CycleGraph::~CycleGraph() { + delete queue; delete discovered; } @@ -38,8 +40,7 @@ void CycleGraph::putNode(const ModelAction *act, CycleNode *node) */ void CycleGraph::putNode(const Promise *promise, CycleNode *node) { - const ModelAction *reader = promise->get_action(); - readerToPromiseNode.put(reader, node); + promiseToNode.put(promise, node); #if SUPPORT_MOD_ORDER_DUMP nodeList.push_back(node); #endif @@ -51,8 +52,7 @@ void CycleGraph::putNode(const Promise *promise, CycleNode *node) */ void CycleGraph::erasePromiseNode(const Promise *promise) { - const ModelAction *reader = promise->get_action(); - readerToPromiseNode.put(reader, NULL); + promiseToNode.put(promise, NULL); #if SUPPORT_MOD_ORDER_DUMP /* Remove the promise node from nodeList */ CycleNode *node = getNode_noCreate(promise); @@ -73,7 +73,7 @@ CycleNode * CycleGraph::getNode_noCreate(const ModelAction *act) const /** @return The corresponding CycleNode, if exists; otherwise NULL */ CycleNode * CycleGraph::getNode_noCreate(const Promise *promise) const { - return readerToPromiseNode.get(promise->get_action()); + return promiseToNode.get(promise); } /** @@ -114,17 +114,22 @@ CycleNode * CycleGraph::getNode(const Promise *promise) } /** - * @return false if the resolution results in a cycle; true otherwise + * Resolve/satisfy a Promise with a particular store ModelAction, taking care + * of the CycleGraph cleanups, including merging any necessary CycleNodes. + * + * @param promise The Promise to resolve + * @param writer The store that will resolve this Promise + * @return false if the resolution results in a cycle (or fails in some other + * way); true otherwise */ -bool CycleGraph::resolvePromise(ModelAction *reader, ModelAction *writer, - promise_list_t *mustResolve) +bool CycleGraph::resolvePromise(const Promise *promise, ModelAction *writer) { - CycleNode *promise_node = readerToPromiseNode.get(reader); + CycleNode *promise_node = promiseToNode.get(promise); CycleNode *w_node = actionToNode.get(writer); ASSERT(promise_node); if (w_node) - return mergeNodes(w_node, promise_node, mustResolve); + return mergeNodes(w_node, promise_node); /* No existing write-node; just convert the promise-node */ promise_node->resolvePromise(writer); erasePromiseNode(promise_node->getPromise()); @@ -140,45 +145,32 @@ bool CycleGraph::resolvePromise(ModelAction *reader, ModelAction *writer, * @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 + * @return false if the merge cannot succeed; true otherwise */ -bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node, - promise_list_t *mustMerge) +bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node) { 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; + if (!promise->is_compatible(w_node->getAction()) || + !promise->same_value(w_node->getAction())) 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; + if (promise_rmw && promise_rmw != w_node->getRMW() && w_node->setRMW(promise_rmw)) return false; - } /* 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); + addNodeEdge(back, w_node); + if (hasCycles) + return false; } /* Transfer forward edges to w_node */ @@ -186,15 +178,9 @@ bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node, 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); + addNodeEdge(w_node, forward); + if (hasCycles) + return false; } erasePromiseNode(promise); @@ -211,29 +197,33 @@ 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 != tonode) { + if (rmwnode->addEdge(tonode)) { + if (!hasCycles) + hasCycles = checkReachable(tonode, rmwnode); - if (rmwnode->addEdge(tonode)) { - rollbackvector.push_back(rmwnode); - added = true; + rollbackvector.push_back(rmwnode); + } } } - return added; + return true; } /** @@ -241,8 +231,8 @@ 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 @@ -257,6 +247,9 @@ 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; @@ -308,24 +301,24 @@ 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); +template bool CycleGraph::addEdge(const Promise *from, const Promise *to); #if SUPPORT_MOD_ORDER_DUMP -static void print_node(const CycleNode *node, FILE *file, int label) +static void print_node(FILE *file, const CycleNode *node, int label) { - modelclock_t idx; if (node->is_promise()) { const Promise *promise = node->getPromise(); - idx = promise->get_action()->get_seq_number(); + int idx = promise->get_index(); fprintf(file, "P%u", idx); if (label) { int first = 1; - fprintf(file, " [label=\"P%u, T", idx); - for (unsigned int i = 0 ; i < model->get_num_threads(); i++) + fprintf(file, " [label=\"P%d, T", idx); + for (unsigned int i = 0 ; i < promise->max_available_thread_idx(); i++) if (promise->thread_is_available(int_to_id(i))) { fprintf(file, "%s%u", first ? "": ",", i); first = 0; @@ -334,31 +327,50 @@ static void print_node(const CycleNode *node, FILE *file, int label) } } else { const ModelAction *act = node->getAction(); - idx = act->get_seq_number(); + 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 Promise *from, const ModelAction *to, const char *prop); +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 *n = nodeList[i]; - print_node(n, file, 1); + print_node(file, n, 1); fprintf(file, ";\n"); - if (n->getRMW() != NULL) { - print_node(n, file, 0); - fprintf(file, " -> "); - print_node(n->getRMW(), file, 0); - fprintf(file, "[style=dotted];\n"); - } - for (unsigned int j = 0; j < n->getNumEdges(); j++) { - print_node(n, file, 0); - fprintf(file, " -> "); - print_node(n->getEdge(j), file, 0); - 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); } } @@ -382,22 +394,20 @@ 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++) { CycleNode *next = node->getEdge(i); if (!discovered->contains(next)) { discovered->put(next, next); - queue.push_back(next); + queue->push_back(next); } } } @@ -405,13 +415,13 @@ 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); @@ -421,40 +431,46 @@ 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; +template bool CycleGraph::checkReachable(const Promise *from, + const ModelAction *to) const; +template bool CycleGraph::checkReachable(const Promise *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(); + queue->clear(); CycleNode *from = actionToNode.get(fromact); - queue.push_back(from); + queue->push_back(from); discovered->put(from, from); - while (!queue.empty()) { - CycleNode *node = queue.back(); - queue.pop_back(); + while (!queue->empty()) { + const CycleNode *node = queue->back(); + queue->pop_back(); - if (!node->is_promise() && - promise->eliminate_thread(node->getAction()->get_tid())) + if (node->getPromise() == promise) return true; + if (!node->is_promise()) + promise->eliminate_thread(node->getAction()->get_tid()); 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); } } } return false; } +/** @brief Begin a new sequence of graph additions which can be rolled back */ void CycleGraph::startChanges() { ASSERT(rollbackvector.empty()); @@ -514,7 +530,7 @@ CycleNode::CycleNode(const Promise *promise) : /** * @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 { @@ -527,11 +543,16 @@ 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(); @@ -544,7 +565,7 @@ 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++) { if (v[i] == n) {