Imported existing code

indra/llplugin/llpluginsharedmemory.h

@@ -0,0 +1,130 @@
+/** 
+ * @file llpluginsharedmemory.h
+ * @brief LLPluginSharedMemory manages a shared memory segment for use by the LLPlugin API.
+ *
+ * $LicenseInfo:firstyear=2008&license=viewergpl$
+ * 
+ * Copyright (c) 2008-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLPLUGINSHAREDMEMORY_H
+#define LL_LLPLUGINSHAREDMEMORY_H
+
+class LLPluginSharedMemoryPlatformImpl;
+
+/**
+ * @brief LLPluginSharedMemory manages a shared memory segment for use by the LLPlugin API.
+ *
+ */
+class LLPluginSharedMemory
+{
+	LOG_CLASS(LLPluginSharedMemory);
+public:
+	LLPluginSharedMemory();
+	~LLPluginSharedMemory();
+	
+	// Parent will use create/destroy, child will use attach/detach.
+	// Message transactions will ensure child attaches after parent creates and detaches before parent destroys.
+	
+   /** 
+    * Creates a shared memory segment, with a name which is guaranteed to be unique on the host at the current time. Used by parent.
+    * Message transactions will (? TODO:DOC - should? must?) ensure child attaches after parent creates and detaches before parent destroys.
+    *
+    * @param[in] size Shared memory size in TODO:DOC units = bytes?.
+    *
+    * @return False for failure, true for success.
+    */
+	bool create(size_t size);
+   /** 
+    * Destroys a shared memory segment. Used by parent.
+    * Message transactions will (? TODO:DOC - should? must?) ensure child attaches after parent creates and detaches before parent destroys.
+    *
+    * @return True. TODO:DOC - always returns true. Is this the intended behavior?
+    */
+	bool destroy(void);
+	
+   /** 
+    * Creates and attaches a name to a shared memory segment. TODO:DOC what's the difference between attach() and create()?
+    *
+    * @param[in] name Name to attach to memory segment
+    * @param[in] size Size of memory segment TODO:DOC in bytes?
+    *
+    * @return False on failure, true otherwise.
+    */
+	bool attach(const std::string &name, size_t size);
+   /** 
+    * Detaches shared memory segment.
+    *
+    * @return False on failure, true otherwise.
+    */
+	bool detach(void);
+
+   /** 
+    * Checks if shared memory is mapped to a non-null address.
+    *
+    * @return True if memory address is non-null, false otherwise.
+    */
+	bool isMapped(void) const { return (mMappedAddress != NULL); };
+   /** 
+    * Get pointer to shared memory.
+    *
+    * @return Pointer to shared memory.
+    */
+	void *getMappedAddress(void) const { return mMappedAddress; };
+   /** 
+    * Get size of shared memory.
+    *
+    * @return Size of shared memory in bytes. TODO:DOC are bytes the correct unit?
+    */
+	size_t getSize(void) const { return mSize; };
+   /** 
+    * Get name of shared memory.
+    *
+    * @return Name of shared memory.
+    */
+	std::string getName() const { return mName; };
+	
+private:
+	bool map(void);
+	bool unmap(void);
+	bool close(void);
+	bool unlink(void);
+	
+	std::string mName;
+	size_t mSize;
+	void *mMappedAddress;
+	bool mNeedsDestroy;
+	
+	LLPluginSharedMemoryPlatformImpl *mImpl;
+	
+	static int sSegmentNumber;
+	static std::string createName();
+	
+};
+
+
+
+#endif // LL_LLPLUGINSHAREDMEMORY_H