/** * @file llpluginprocesschild.cpp * @brief LLPluginProcessChild handles the child side of the external-process plugin API. * * @cond * $LicenseInfo:firstyear=2008&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ * @endcond */ #include "linden_common.h" #include "llpluginprocesschild.h" #include "llplugininstance.h" #include "llpluginmessagepipe.h" #include "llpluginmessageclasses.h" static const F32 GOODBYE_SECONDS = 20.0f; static const F32 HEARTBEAT_SECONDS = 1.0f; static const F32 PLUGIN_IDLE_SECONDS = 1.0f / 100.0f; // Each call to idle will give the plugin this much time. LLPluginProcessChild::LLPluginProcessChild() { mState = STATE_UNINITIALIZED; mInstance = NULL; mSocket = LLSocket::create(gAPRPoolp, LLSocket::STREAM_TCP); mSleepTime = PLUGIN_IDLE_SECONDS; // default: send idle messages at 100Hz mCPUElapsed = 0.0f; mBlockingRequest = false; mBlockingResponseReceived = false; } LLPluginProcessChild::~LLPluginProcessChild() { if(mInstance != NULL) { sendMessageToPlugin(LLPluginMessage("base", "cleanup")); // IMPORTANT: under some (unknown) circumstances the apr_dso_unload() triggered when mInstance is deleted // appears to fail and lock up which means that a given instance of the slplugin process never exits. // This is bad, especially when users try to update their version of SL - it fails because the slplugin // process as well as a bunch of plugin specific files are locked and cannot be overwritten. exit( 0 ); //delete mInstance; //mInstance = NULL; } } void LLPluginProcessChild::killSockets(void) { killMessagePipe(); mSocket.reset(); } void LLPluginProcessChild::init(U32 launcher_port) { mLauncherHost = LLHost("127.0.0.1", launcher_port); setState(STATE_INITIALIZED); } void LLPluginProcessChild::idle(void) { bool idle_again; do { if(APR_STATUS_IS_EOF(mSocketError)) { // Plugin socket was closed. This covers both normal plugin termination and host crashes. setState(STATE_ERROR); } else if(mSocketError != APR_SUCCESS) { LL_INFOS("Plugin") << "message pipe is in error state (" << mSocketError << "), moving to STATE_ERROR"<< LL_ENDL; setState(STATE_ERROR); } if((mState > STATE_INITIALIZED) && (mMessagePipe == NULL)) { // The pipe has been closed -- we're done. // TODO: This could be slightly more subtle, but I'm not sure it needs to be. LL_INFOS("Plugin") << "message pipe went away, moving to STATE_ERROR"<< LL_ENDL; setState(STATE_ERROR); } // If a state needs to go directly to another state (as a performance enhancement), it can set idle_again to true after calling setState(). // USE THIS CAREFULLY, since it can starve other code. Specifically make sure there's no way to get into a closed cycle and never return. // When in doubt, don't do it. idle_again = false; if(mInstance != NULL) { // Provide some time to the plugin mInstance->idle(); } switch(mState) { case STATE_UNINITIALIZED: break; case STATE_INITIALIZED: if(mSocket->blockingConnect(mLauncherHost)) { // This automatically sets mMessagePipe new LLPluginMessagePipe(this, mSocket); setState(STATE_CONNECTED); } else { // connect failed setState(STATE_ERROR); } break; case STATE_CONNECTED: sendMessageToParent(LLPluginMessage(LLPLUGIN_MESSAGE_CLASS_INTERNAL, "hello")); setState(STATE_PLUGIN_LOADING); break; case STATE_PLUGIN_LOADING: if(!mPluginFile.empty()) { mInstance = new LLPluginInstance(this); if(mInstance->load(mPluginDir, mPluginFile) == 0) { mHeartbeat.start(); mHeartbeat.setTimerExpirySec(HEARTBEAT_SECONDS); mCPUElapsed = 0.0f; setState(STATE_PLUGIN_LOADED); } else { setState(STATE_ERROR); } } break; case STATE_PLUGIN_LOADED: { setState(STATE_PLUGIN_INITIALIZING); LLPluginMessage message("base", "init"); sendMessageToPlugin(message); } break; case STATE_PLUGIN_INITIALIZING: // waiting for init_response... break; case STATE_RUNNING: if(mInstance != NULL) { // Provide some time to the plugin LLPluginMessage message("base", "idle"); message.setValueReal("time", PLUGIN_IDLE_SECONDS); sendMessageToPlugin(message); mInstance->idle(); if(mHeartbeat.hasExpired()) { // This just proves that we're not stuck down inside the plugin code. LLPluginMessage heartbeat(LLPLUGIN_MESSAGE_CLASS_INTERNAL, "heartbeat"); // Calculate the approximage CPU usage fraction (floating point value between 0 and 1) used by the plugin this heartbeat cycle. // Note that this will not take into account any threads or additional processes the plugin spawns, but it's a first approximation. // If we could write OS-specific functions to query the actual CPU usage of this process, that would be a better approximation. heartbeat.setValueReal("cpu_usage", mCPUElapsed / mHeartbeat.getElapsedTimeF64()); sendMessageToParent(heartbeat); mHeartbeat.reset(); mHeartbeat.setTimerExpirySec(HEARTBEAT_SECONDS); mCPUElapsed = 0.0f; } } // receivePluginMessage will transition to STATE_UNLOADING break; case STATE_SHUTDOWNREQ: if (mInstance != NULL) { sendMessageToPlugin(LLPluginMessage("base", "cleanup")); delete mInstance; mInstance = NULL; } setState(STATE_UNLOADING); mWaitGoodbye.setTimerExpirySec(GOODBYE_SECONDS); break; case STATE_UNLOADING: // waiting for goodbye from plugin. if (mWaitGoodbye.hasExpired()) { LL_WARNS() << "Wait for goodbye expired. Advancing to UNLOADED" << LL_ENDL; setState(STATE_UNLOADED); } break; case STATE_UNLOADED: killSockets(); setState(STATE_DONE); break; case STATE_ERROR: // Close the socket to the launcher killSockets(); // TODO: Where do we go from here? Just exit()? setState(STATE_DONE); break; case STATE_DONE: // just sit here. break; } } while (idle_again); } void LLPluginProcessChild::sleep(F64 seconds) { deliverQueuedMessages(); if(mMessagePipe) { mMessagePipe->pump(seconds); } else { ms_sleep((int)(seconds * 1000.0f)); } } void LLPluginProcessChild::pump(void) { deliverQueuedMessages(); if(mMessagePipe) { mMessagePipe->pump(0.0f); } else { // Should we warn here? } } bool LLPluginProcessChild::isRunning(void) { bool result = false; if(mState == STATE_RUNNING) result = true; return result; } bool LLPluginProcessChild::isDone(void) { bool result = false; switch(mState) { case STATE_DONE: result = true; break; default: break; } return result; } void LLPluginProcessChild::sendMessageToPlugin(const LLPluginMessage &message) { if (mInstance) { std::string buffer = message.generate(); LL_DEBUGS("Plugin") << "Sending to plugin: " << buffer << LL_ENDL; LLTimer elapsed; mInstance->sendMessage(buffer); mCPUElapsed += elapsed.getElapsedTimeF64(); } else { LL_WARNS("Plugin") << "mInstance == NULL" << LL_ENDL; } } void LLPluginProcessChild::sendMessageToParent(const LLPluginMessage &message) { std::string buffer = message.generate(); LL_DEBUGS("Plugin") << "Sending to parent: " << buffer << LL_ENDL; writeMessageRaw(buffer); } void LLPluginProcessChild::receiveMessageRaw(const std::string &message) { // Incoming message from the TCP Socket LL_DEBUGS("Plugin") << "Received from parent: " << message << LL_ENDL; // Decode this message LLPluginMessage parsed; parsed.parse(message); if(mBlockingRequest) { // We're blocking the plugin waiting for a response. if(parsed.hasValue("blocking_response")) { // This is the message we've been waiting for -- fall through and send it immediately. mBlockingResponseReceived = true; } else { // Still waiting. Queue this message and don't process it yet. mMessageQueue.push(message); return; } } bool passMessage = true; // FIXME: how should we handle queueing here? { std::string message_class = parsed.getClass(); if(message_class == LLPLUGIN_MESSAGE_CLASS_INTERNAL) { passMessage = false; std::string message_name = parsed.getName(); if(message_name == "load_plugin") { mPluginFile = parsed.getValue("file"); mPluginDir = parsed.getValue("dir"); } else if (message_name == "shutdown_plugin") { setState(STATE_SHUTDOWNREQ); } else if(message_name == "shm_add") { std::string name = parsed.getValue("name"); size_t size = (size_t)parsed.getValueS32("size"); sharedMemoryRegionsType::iterator iter = mSharedMemoryRegions.find(name); if(iter != mSharedMemoryRegions.end()) { // Need to remove the old region first LL_WARNS("Plugin") << "Adding a duplicate shared memory segment!" << LL_ENDL; } else { // This is a new region LLPluginSharedMemory *region = new LLPluginSharedMemory; if(region->attach(name, size)) { mSharedMemoryRegions.insert(sharedMemoryRegionsType::value_type(name, region)); std::stringstream addr; addr << region->getMappedAddress(); // Send the add notification to the plugin LLPluginMessage message("base", "shm_added"); message.setValue("name", name); message.setValueS32("size", (S32)size); message.setValuePointer("address", region->getMappedAddress()); sendMessageToPlugin(message); // and send the response to the parent message.setMessage(LLPLUGIN_MESSAGE_CLASS_INTERNAL, "shm_add_response"); message.setValue("name", name); sendMessageToParent(message); } else { LL_WARNS("Plugin") << "Couldn't create a shared memory segment!" << LL_ENDL; delete region; } } } else if(message_name == "shm_remove") { std::string name = parsed.getValue("name"); sharedMemoryRegionsType::iterator iter = mSharedMemoryRegions.find(name); if(iter != mSharedMemoryRegions.end()) { // forward the remove request to the plugin -- its response will trigger us to detach the segment. LLPluginMessage message("base", "shm_remove"); message.setValue("name", name); sendMessageToPlugin(message); } else { LL_WARNS("Plugin") << "shm_remove for unknown memory segment!" << LL_ENDL; } } else if(message_name == "sleep_time") { mSleepTime = llmax(parsed.getValueReal("time"), 1.0 / 100.0); // clamp to maximum of 100Hz } else if(message_name == "crash") { // Crash the plugin LL_ERRS("Plugin") << "Plugin crash requested." << LL_ENDL; } else if(message_name == "hang") { // Hang the plugin LL_WARNS("Plugin") << "Plugin hang requested." << LL_ENDL; while(1) { // wheeeeeeeee...... } } else { LL_WARNS("Plugin") << "Unknown internal message from parent: " << message_name << LL_ENDL; } } } if(passMessage && mInstance != NULL) { LLTimer elapsed; mInstance->sendMessage(message); mCPUElapsed += elapsed.getElapsedTimeF64(); } } /* virtual */ void LLPluginProcessChild::receivePluginMessage(const std::string &message) { LL_DEBUGS("Plugin") << "Received from plugin: " << message << LL_ENDL; if(mBlockingRequest) { // LL_ERRS("Plugin") << "Can't send a message while already waiting on a blocking request -- aborting!" << LL_ENDL; } // Incoming message from the plugin instance bool passMessage = true; // FIXME: how should we handle queueing here? // Intercept certain base messages (responses to ones sent by this class) { // Decode this message LLPluginMessage parsed; parsed.parse(message); if(parsed.hasValue("blocking_request")) { mBlockingRequest = true; } std::string message_class = parsed.getClass(); if(message_class == "base") { std::string message_name = parsed.getName(); if(message_name == "init_response") { // The plugin has finished initializing. setState(STATE_RUNNING); // Don't pass this message up to the parent passMessage = false; LLPluginMessage new_message(LLPLUGIN_MESSAGE_CLASS_INTERNAL, "load_plugin_response"); LLSD versions = parsed.getValueLLSD("versions"); new_message.setValueLLSD("versions", versions); if(parsed.hasValue("plugin_version")) { std::string plugin_version = parsed.getValue("plugin_version"); new_message.setValueLLSD("plugin_version", plugin_version); } // Let the parent know it's loaded and initialized. sendMessageToParent(new_message); } else if (message_name == "goodbye") { setState(STATE_UNLOADED); } else if(message_name == "shm_remove_response") { // Don't pass this message up to the parent passMessage = false; std::string name = parsed.getValue("name"); sharedMemoryRegionsType::iterator iter = mSharedMemoryRegions.find(name); if(iter != mSharedMemoryRegions.end()) { // detach the shared memory region iter->second->detach(); // and remove it from our map mSharedMemoryRegions.erase(iter); // Finally, send the response to the parent. LLPluginMessage message(LLPLUGIN_MESSAGE_CLASS_INTERNAL, "shm_remove_response"); message.setValue("name", name); sendMessageToParent(message); } else { LL_WARNS("Plugin") << "shm_remove_response for unknown memory segment!" << LL_ENDL; } } } } if(passMessage) { LL_DEBUGS("Plugin") << "Passing through to parent: " << message << LL_ENDL; writeMessageRaw(message); } while(mBlockingRequest) { // The plugin wants to block and wait for a response to this message. sleep(mSleepTime); // this will pump the message pipe and process messages if(mBlockingResponseReceived || mSocketError != APR_SUCCESS || (mMessagePipe == NULL)) { // Response has been received, or we've hit an error state. Stop waiting. mBlockingRequest = false; mBlockingResponseReceived = false; } } } void LLPluginProcessChild::setState(EState state) { LL_DEBUGS("Plugin") << "setting state to " << state << LL_ENDL; mState = state; }; void LLPluginProcessChild::deliverQueuedMessages() { if(!mBlockingRequest) { while(!mMessageQueue.empty()) { receiveMessageRaw(mMessageQueue.front()); mMessageQueue.pop(); } } }