Imported existing code

indra/llplugin/llplugininstance.h

@@ -0,0 +1,104 @@
+/** 
+ * @file llplugininstance.h
+ * @brief LLPluginInstance handles loading the dynamic library of a plugin and setting up its entry points for message passing.
+ *
+ * $LicenseInfo:firstyear=2008&license=viewergpl$
+ * 
+ * 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_LLPLUGININSTANCE_H
+#define LL_LLPLUGININSTANCE_H
+
+#include "llstring.h"
+#include "llapr.h"
+
+#include "apr_dso.h"
+
+/**
+ * @brief LLPluginInstanceMessageListener receives messages sent from the plugin loader shell to the plugin.
+ */
+class LLPluginInstanceMessageListener
+{
+public:
+	virtual ~LLPluginInstanceMessageListener();
+   /** Plugin receives message from plugin loader shell. */
+	virtual void receivePluginMessage(const std::string &message) = 0;
+};
+
+/**
+ * @brief LLPluginInstance handles loading the dynamic library of a plugin and setting up its entry points for message passing.
+ */
+class LLPluginInstance
+{
+	LOG_CLASS(LLPluginInstance);
+public:
+	LLPluginInstance(LLPluginInstanceMessageListener *owner);
+	virtual ~LLPluginInstance();
+	
+	// Load a plugin dll/dylib/so
+	// Returns 0 if successful, APR error code or error code returned from the plugin's init function on failure.
+	int load(std::string &plugin_file);
+	
+	// Sends a message to the plugin.
+	void sendMessage(const std::string &message);
+	
+   // TODO:DOC is this comment obsolete? can't find "send_count" anywhere in indra tree.
+	// send_count is the maximum number of message to process from the send queue.  If negative, it will drain the queue completely.
+	// The receive queue is always drained completely.
+	// Returns the total number of messages processed from both queues.
+	void idle(void);
+	
+	/** The signature of the function for sending a message from plugin to plugin loader shell.
+    *
+	 * @param[in] message_string Null-terminated C string 
+    * @param[in] user_data The opaque reference that the callee supplied during setup.
+    */
+	typedef void (*sendMessageFunction) (const char *message_string, void **user_data);
+
+	/** The signature of the plugin init function. TODO:DOC check direction (pluging loader shell to plugin?)
+    *
+    * @param[in] host_user_data Data from plugin loader shell.
+    * @param[in] plugin_send_function Function for sending from the plugin loader shell to plugin.
+    */
+	typedef int (*pluginInitFunction) (sendMessageFunction host_send_func, void *host_user_data, sendMessageFunction *plugin_send_func, void **plugin_user_data);
+	
+   /** Name of plugin init function */
+	static const char *PLUGIN_INIT_FUNCTION_NAME;
+	
+private:
+	static void staticReceiveMessage(const char *message_string, void **user_data);
+	void receiveMessage(const char *message_string);
+
+	apr_dso_handle_t *mDSOHandle;
+	
+	void *mPluginUserData;
+	sendMessageFunction mPluginSendMessageFunction;
+	
+	LLPluginInstanceMessageListener *mOwner;
+};
+
+#endif // LL_LLPLUGININSTANCE_H