in progress with integratign new shm in multi

slsDetectorSoftware/sharedMemory/SharedMemory.h

@@ -0,0 +1,117 @@
+#pragma once
+/************************************************
+ * @file SharedMemory.h
+ * @short functions basic implemenation of
+ * shared memory
+ ***********************************************/
+/**
+ *@short functions basic implemenation of shared memory
+ */
+
+#include <iostream>
+#include <string>
+
+class SharedMemory{
+public:
+	/**
+	 * Constructor
+	 * creates the single/multi detector shared memory name
+	 * @param multiId multi detector id
+     * @param singleId sls detector id, -1 if a multi detector shared memory
+ 	 */
+	SharedMemory(int multiId, int singleId);
+
+	/**
+	 * Destructor
+	 */
+	~SharedMemory();
+
+    /**
+     * Verify if it exists
+     * @param name of shared memory
+     * @return true if exists, else false
+     */
+    static bool IsExisting(std::string name);
+
+	/**
+	 * Get shared memory name
+	 */
+	std::string GetName();
+
+    /**
+     * Create Shared memory and call MapSharedMemory to map it to an address
+     * throws a SharedMemoryException exception on failure to create, ftruncate or map
+     * @param sz of shared memory
+     * @param addr double pointer to address to be mapped
+     */
+    void* CreateSharedMemory(size_t sz);
+
+    /**
+     * Open existing Shared memory and call MapSharedMemory to map it to an address
+     * throws a SharedMemoryException exception on failure to open, incorrect size if verify true, or map
+     * @param sz of shared memory
+     * @param addr double pointer to address to be mapped
+     * @param verify true to verify if the size matches existing one and return fail if does not match
+     */
+    void* OpenSharedMemory(size_t sz, bool verify = true);
+
+    /**
+     * Unmap shared memory from an address
+     * throws a SharedMemoryException exception on failure
+     * @param addr double pointer to address to be mapped
+     */
+    void UnmapSharedMemory(void* addr);
+
+	/**
+	 * Remove existing Shared memory
+	 */
+	void RemoveSharedMemory();
+
+    /**
+     * Maximum length of name as from man pages
+     */
+    static const int NAME_MAX = 255;
+
+private:
+    /**
+     * Create Shared memory name
+     * throws exception if name created is longer than required 255(manpages)
+     * @param multiId multi detector id
+     * @param singleId sls detector id, -1 if a multi detector shared memory
+     * @returns shared memory name
+     */
+    std::string ConstructSharedMemoryName(int multiId, int singleId);
+
+    /**
+     * Map shared memory to an address
+     * throws a SharedMemoryException exception on failure
+     * @param addr double pointer to address to be mapped
+     * @param sz of shared memory
+     */
+	//template <typename myType>
+   // void MapSharedMemory(myType*& addr, size_t sz);
+    void* MapSharedMemory(size_t sz);
+
+    /**
+     * Verify if existing shared memory size matches expected size
+     * @param sz expected size of shared memory, replaced with smaller size if size does not match
+     * @return 0 for success, 1 for fail
+     */
+    int VerifySizeMatch(size_t expectedSize);
+
+    /**
+     * Remove existing Shared memory
+     * @param name name of shared memory (should be less than NAME_MAX)
+     */
+	void RemoveSharedMemory(std::string name);
+
+	/** Shared memory name */
+	std::string name;
+
+	/** File descriptor */
+	int fd;
+
+	/** shm size */
+	size_t shmSize;
+
+};