Initial commit of libspinscale library

include/spinscale/dependencyGraph.h

@@ -0,0 +1,85 @@
+#ifndef DEPENDENCY_GRAPH_H
+#define DEPENDENCY_GRAPH_H
+
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+#include <memory>
+
+namespace sscl {
+
+// Forward declarations
+class AsynchronousContinuationChainLink;
+
+/**
+ * @brief DependencyGraph - Represents a directed graph for lock dependency analysis
+ *
+ * This graph represents dependencies between continuations (lockvokers) where
+ * an edge from A to B means that continuation A wants a lock that is held by
+ * continuation B. This is used to detect circular dependencies (gridlocks).
+ */
+class DependencyGraph
+{
+public:
+	typedef std::shared_ptr<AsynchronousContinuationChainLink> Node;
+	// Each node maps to a set of nodes it depends on
+	typedef std::unordered_map<Node, std::unordered_set<Node>> AdjacencyList;
+
+public:
+	void addNode(const Node& node);
+
+	/**
+	 * @brief Add a directed edge from source to target
+	 * @param source The continuation that wants a lock
+	 * @param target The continuation that holds the wanted lock
+	 */
+	void addEdge(const Node& source, const Node& target);
+
+	/**
+	 * @brief Find all cycles in the graph using DFS
+	 * @return Vector of cycles, where each cycle is a vector of nodes
+	 */
+	std::vector<std::vector<Node>> findCycles() const;
+
+	/**
+	 * @brief Check if there are any cycles in the graph
+	 * @return true if cycles exist, false otherwise
+	 */
+	bool hasCycles() const;
+
+	/**
+	 * @brief Get the number of nodes in the graph
+	 * @return Number of nodes
+	 */
+	size_t getNodeCount() const;
+
+	/**
+	 * @brief Get the adjacency list for debugging
+	 * @return Reference to the adjacency list
+	 */
+	const AdjacencyList& getAdjacencyList() const { return adjacencyList; }
+
+private:
+	/**
+	 * @brief DFS helper for cycle detection
+	 * @param node Current node being visited
+	 * @param visited Set of nodes that have been fully processed
+	 * @param recursionStack Set of nodes currently in the recursion stack
+	 * @param path Current path being explored
+	 * @param cycles Vector to store found cycles
+	 */
+	void dfsCycleDetection(
+		const Node& node,
+		std::unordered_set<Node>& visited,
+		std::unordered_set<Node>& recursionStack,
+		std::vector<Node>& path,
+		std::vector<std::vector<Node>>& cycles)
+		const;
+
+private:
+	AdjacencyList adjacencyList;
+};
+
+} // namespace sscl
+
+#endif // DEPENDENCY_GRAPH_H