/indra/llplugin/llplugininstance.cpp

  1/** 
  2 * @file llplugininstance.cpp
  3 * @brief LLPluginInstance handles loading the dynamic library of a plugin and setting up its entry points for message passing.
  4 *
  5 * @cond
  6 * $LicenseInfo:firstyear=2008&license=viewerlgpl$
  7 * Second Life Viewer Source Code
  8 * Copyright (C) 2010, Linden Research, Inc.
  9 * 
 10 * This library is free software; you can redistribute it and/or
 11 * modify it under the terms of the GNU Lesser General Public
 12 * License as published by the Free Software Foundation;
 13 * version 2.1 of the License only.
 14 * 
 15 * This library is distributed in the hope that it will be useful,
 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 18 * Lesser General Public License for more details.
 19 * 
 20 * You should have received a copy of the GNU Lesser General Public
 21 * License along with this library; if not, write to the Free Software
 22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 23 * 
 24 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 25 * $/LicenseInfo$
 26 * @endcond
 27 */
 28
 29#include "linden_common.h"
 30
 31#include "llplugininstance.h"
 32
 33#include "llapr.h"
 34
 35#if LL_WINDOWS
 36#include "direct.h"	// needed for _chdir()
 37#endif
 38
 39/** Virtual destructor. */
 40LLPluginInstanceMessageListener::~LLPluginInstanceMessageListener()
 41{
 42}
 43
 44/** 
 45 * TODO:DOC describe how it's used
 46 */
 47const char *LLPluginInstance::PLUGIN_INIT_FUNCTION_NAME = "LLPluginInitEntryPoint";
 48
 49/** 
 50 * Constructor.
 51 *
 52 * @param[in] owner Plugin instance. TODO:DOC is this a good description of what "owner" is?
 53 */
 54LLPluginInstance::LLPluginInstance(LLPluginInstanceMessageListener *owner) :
 55	mDSOHandle(NULL),
 56	mPluginUserData(NULL),
 57	mPluginSendMessageFunction(NULL)
 58{
 59	mOwner = owner;
 60}
 61
 62/** 
 63 * Destructor.
 64 */
 65LLPluginInstance::~LLPluginInstance()
 66{
 67	if(mDSOHandle != NULL)
 68	{
 69		apr_dso_unload(mDSOHandle);
 70		mDSOHandle = NULL;
 71	}
 72}
 73
 74/** 
 75 * Dynamically loads the plugin and runs the plugin's init function.
 76 *
 77 * @param[in] plugin_file Name of plugin dll/dylib/so. TODO:DOC is this correct? see .h
 78 * @return 0 if successful, APR error code or error code from the plugin's init function on failure.
 79 */
 80int LLPluginInstance::load(const std::string& plugin_dir, std::string &plugin_file)
 81{
 82	pluginInitFunction init_function = NULL;
 83	
 84	if ( plugin_dir.length() )
 85	{
 86#if LL_WINDOWS
 87		// VWR-21275:
 88		// *SOME* Windows systems fail to load the Qt plugins if the current working
 89		// directory is not the same as the directory with the Qt DLLs in.
 90		// This should not cause any run time issues since we are changing the cwd for the
 91		// plugin shell process and not the viewer.
 92		// Changing back to the previous directory is not necessary since the plugin shell
 93		// quits once the plugin exits.
 94		_chdir( plugin_dir.c_str() );	
 95#endif
 96	};
 97
 98	int result = apr_dso_load(&mDSOHandle,
 99					  plugin_file.c_str(),
100					  gAPRPoolp);
101	if(result != APR_SUCCESS)
102	{
103		char buf[1024];
104		apr_dso_error(mDSOHandle, buf, sizeof(buf));
105
106		LL_WARNS("Plugin") << "apr_dso_load of " << plugin_file << " failed with error " << result << " , additional info string: " << buf << LL_ENDL;
107		
108	}
109	
110	if(result == APR_SUCCESS)
111	{
112		result = apr_dso_sym((apr_dso_handle_sym_t*)&init_function,
113						 mDSOHandle,
114						 PLUGIN_INIT_FUNCTION_NAME);
115
116		if(result != APR_SUCCESS)
117		{
118			LL_WARNS("Plugin") << "apr_dso_sym failed with error " << result << LL_ENDL;
119		}
120	}
121	
122	if(result == APR_SUCCESS)
123	{
124		result = init_function(staticReceiveMessage, (void*)this, &mPluginSendMessageFunction, &mPluginUserData);
125
126		if(result != APR_SUCCESS)
127		{
128			LL_WARNS("Plugin") << "call to init function failed with error " << result << LL_ENDL;
129		}
130	}
131	
132	return (int)result;
133}
134
135/** 
136 * Sends a message to the plugin.
137 *
138 * @param[in] message Message
139 */
140void LLPluginInstance::sendMessage(const std::string &message)
141{
142	if(mPluginSendMessageFunction)
143	{
144		LL_DEBUGS("Plugin") << "sending message to plugin: \"" << message << "\"" << LL_ENDL;
145		mPluginSendMessageFunction(message.c_str(), &mPluginUserData);
146	}
147	else
148	{
149		LL_WARNS("Plugin") << "dropping message: \"" << message << "\"" << LL_ENDL;
150	}
151}
152
153/**
154 * Idle. TODO:DOC what's the purpose of this?
155 *
156 */
157void LLPluginInstance::idle(void)
158{
159}
160
161// static
162void LLPluginInstance::staticReceiveMessage(const char *message_string, void **user_data)
163{
164	// TODO: validate that the user_data argument is still a valid LLPluginInstance pointer
165	// we could also use a key that's looked up in a map (instead of a direct pointer) for safety, but that's probably overkill
166	LLPluginInstance *self = (LLPluginInstance*)*user_data;
167	self->receiveMessage(message_string);
168}
169
170/**
171 * Plugin receives message from plugin loader shell.
172 *
173 * @param[in] message_string Message
174 */
175void LLPluginInstance::receiveMessage(const char *message_string)
176{
177	if(mOwner)
178	{
179		LL_DEBUGS("Plugin") << "processing incoming message: \"" << message_string << "\"" << LL_ENDL;		
180		mOwner->receivePluginMessage(message_string);
181	}
182	else
183	{
184		LL_WARNS("Plugin") << "dropping incoming message: \"" << message_string << "\"" << LL_ENDL;		
185	}	
186}