cyclegraph: return 'added' status for addEdge()

[c11tester.git] / cyclegraph.h

diff --git a/cyclegraph.h b/cyclegraph.h
index 6b3d93e5e45ec661d3acd4db987796b9b1adaea6..749abf8ca847d9969016356101b153c4d0688a84 100644 (file)
--- a/cyclegraph.h
+++ b/cyclegraph.h
@@ -19,17 +19,24 @@ class Promise;
 class CycleNode;
 class ModelAction;
 
+typedef std::vector< const Promise *, ModelAlloc<const Promise *> > promise_list_t;
+
 /** @brief A graph of Model Actions for tracking cycles. */
 class CycleGraph {
  public:
        CycleGraph();
        ~CycleGraph();
-       void addEdge(const ModelAction *from, const ModelAction *to);
+
+       template <typename T, typename U>
+       bool addEdge(const T from, const U to);
+
        bool checkForCycles() const;
-       bool checkForRMWViolation() const;
        void addRMWEdge(const ModelAction *from, const ModelAction *rmw);
        bool checkPromise(const ModelAction *from, Promise *p) const;
-       bool checkReachable(const ModelAction *from, const ModelAction *to) const;
+
+       template <typename T>
+       bool checkReachable(const ModelAction *from, const T *to) const;
+
        void startChanges();
        void commitChanges();
        void rollbackChanges();
@@ -38,60 +45,132 @@ class CycleGraph {
        void dumpGraphToFile(const char *filename) const;
 #endif
 
+       bool resolvePromise(ModelAction *reader, ModelAction *writer,
+                       promise_list_t *mustResolve);
+
        SNAPSHOTALLOC
  private:
+       bool addNodeEdge(CycleNode *fromnode, CycleNode *tonode);
        void putNode(const ModelAction *act, CycleNode *node);
-       CycleNode * getNode(const ModelAction *);
-       HashTable<CycleNode *, CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free> *discovered;
+       CycleNode * getNode(const ModelAction *act);
+       CycleNode * getNode(const Promise *promise);
+       CycleNode * getNode_noCreate(const ModelAction *act) const;
+       CycleNode * getNode_noCreate(const Promise *promise) const;
+       bool mergeNodes(CycleNode *node1, CycleNode *node2,
+                       promise_list_t *mustMerge);
+
+       HashTable<const CycleNode *, const CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free> *discovered;
 
        /** @brief A table for mapping ModelActions to CycleNodes */
        HashTable<const ModelAction *, CycleNode *, uintptr_t, 4> actionToNode;
+       /** @brief A table for mapping reader ModelActions to Promise
+        *  CycleNodes */
+       HashTable<const ModelAction *, CycleNode *, uintptr_t, 4> readerToPromiseNode;
+
 #if SUPPORT_MOD_ORDER_DUMP
        std::vector<CycleNode *> nodeList;
 #endif
 
-       bool checkReachable(CycleNode *from, CycleNode *to) const;
+       bool checkReachable(const CycleNode *from, const CycleNode *to) const;
 
        /** @brief A flag: true if this graph contains cycles */
        bool hasCycles;
        bool oldCycles;
 
-       bool hasRMWViolation;
-       bool oldRMWViolation;
-
        std::vector< CycleNode *, SnapshotAlloc<CycleNode *> > rollbackvector;
        std::vector< CycleNode *, SnapshotAlloc<CycleNode *> > rmwrollbackvector;
 };
 
-/** @brief A node within a CycleGraph; corresponds to one ModelAction */
+/**
+ * @brief A node within a CycleGraph; corresponds either to one ModelAction or
+ * to a promised future value
+ */
 class CycleNode {
  public:
        CycleNode(const ModelAction *act);
+       CycleNode(const Promise *promise);
        bool addEdge(CycleNode *node);
        CycleNode * getEdge(unsigned int i) const;
        unsigned int getNumEdges() const;
+       CycleNode * getBackEdge(unsigned int i) const;
+       unsigned int getNumBackEdges() const;
+       CycleNode * removeEdge();
+       CycleNode * removeBackEdge();
+
        bool setRMW(CycleNode *);
        CycleNode * getRMW() const;
+       void clearRMW() { hasRMW = NULL; }
        const ModelAction * getAction() const { return action; }
+       const Promise * getPromise() const { return promise; }
 
        void popEdge() {
                edges.pop_back();
        }
-       void clearRMW() {
-               hasRMW = NULL;
-       }
+
+       bool is_promise() const { return !action; }
+       void resolvePromise(const ModelAction *writer);
 
        SNAPSHOTALLOC
  private:
        /** @brief The ModelAction that this node represents */
        const ModelAction *action;
 
+       /** @brief The promise represented by this node; only valid when action
+        * is NULL */
+       const Promise *promise;
+
        /** @brief The edges leading out from this node */
        std::vector< CycleNode *, SnapshotAlloc<CycleNode *> > edges;
 
+       /** @brief The edges leading into this node */
+       std::vector< CycleNode *, SnapshotAlloc<CycleNode *> > back_edges;
+
        /** Pointer to a RMW node that reads from this node, or NULL, if none
         * exists */
        CycleNode *hasRMW;
 };
 
+/*
+ * @brief Adds an edge between objects
+ *
+ * This function will add an edge between any two objects which can be
+ * associated with a CycleNode. That is, if they have a CycleGraph::getNode
+ * implementation.
+ *
+ * The object to is ordered after the object from.
+ *
+ * @param to The edge points to this object, of type T
+ * @param from The edge comes from this object, of type U
+ * @return True, if new edge(s) are added; otherwise false
+ */
+template <typename T, typename U>
+bool CycleGraph::addEdge(const T from, const U to)
+{
+       ASSERT(from);
+       ASSERT(to);
+
+       CycleNode *fromnode = getNode(from);
+       CycleNode *tonode = getNode(to);
+
+       return addNodeEdge(fromnode, tonode);
+}
+
+/**
+ * Checks whether one ModelAction can reach another ModelAction/Promise
+ * @param from The ModelAction from which to begin exploration
+ * @param to The ModelAction or Promise to reach
+ * @return True, @a from can reach @a to; otherwise, false
+ */
+template <typename T>
+bool CycleGraph::checkReachable(const ModelAction *from, const T *to) const
+{
+       CycleNode *fromnode = getNode_noCreate(from);
+       CycleNode *tonode = getNode_noCreate(to);
+
+       if (!fromnode || !tonode)
+               return false;
+
+       return checkReachable(fromnode, tonode);
+}
+
 #endif /* __CYCLEGRAPH_H__ */