Fixed #8449: Races when server is closed during forced database shutdown

Author: AlexPeshkoff

src/common/classes/init.h

@@ -159,6 +159,11 @@ class GlobalPtr : private InstanceControl
 	{
 		return instance;
 	}
+
+	operator bool() noexcept
+	{
+		return instance;
+	}
 };
 
 // InitMutex - executes static void C::init() once and only once

src/yvalve/MasterImplementation.cpp

@@ -404,6 +404,11 @@ Mutex& pauseTimer()
 	return timerPause;
 }
 
+bool timerThreadStopped()
+{
+	return stopTimerThread.value() != 0;
+}
+
 } // namespace Why
 
 

src/yvalve/MasterImplementation.h

@@ -72,6 +72,8 @@ namespace Why
 	void shutdownTimers();
 
 	Firebird::Mutex& pauseTimer();
+
+	bool timerThreadStopped();
 } // namespace Why
 
 #endif // YVALVE_MASTER_IMPLEMENTATION_H

src/yvalve/PluginManager.cpp

@@ -36,6 +36,7 @@
 #include "../common/classes/fb_string.h"
 #include "../common/classes/init.h"
 #include "../common/classes/semaphore.h"
+#include "../common/classes/RefMutex.h"
 #include "../common/config/config.h"
 #include "../common/config/config_file.h"
 #include "../common/utils_proto.h"
@@ -453,7 +454,7 @@ namespace
 						 const PathName& pplugName)
 			: module(pmodule), regPlugin(preg), pluginLoaderConfig(pconfig),
 			  confName(getPool(), pconfName), plugName(getPool(), pplugName),
-			  delay(DEFAULT_DELAY)
+			  processingDelayedDelete(false), delay(DEFAULT_DELAY)
 		{
 			if (pluginLoaderConfig.hasData())
 			{
@@ -470,7 +471,7 @@ namespace
 #ifdef DEBUG_PLUGINS
 			RegisteredPlugin& r(module->getPlugin(regPlugin));
 			fprintf(stderr, " ConfiguredPlugin %s module %s registered as %s type %d order %d\n",
-					plugName.c_str(), module->getName(), r.name, r.type, regPlugin);
+					plugName.c_str(), module->getName(), r.name.c_str(), r.type, regPlugin);
 #endif
 		}
 
@@ -514,6 +515,8 @@ namespace
 		{ }
 
 		int release();
+		static void processDelayedDelete();
+
 	private:
 		~ConfiguredPlugin() {}
 		void destroy();
@@ -523,6 +526,7 @@ namespace
 		RefPtr<ConfigFile> pluginLoaderConfig;
 		PathName confName;
 		PathName plugName;
+		bool processingDelayedDelete;
 
 		static const FB_UINT64 DEFAULT_DELAY = 1000000 * 60;		// 1 min
 		FB_UINT64 delay;
@@ -585,7 +589,7 @@ namespace
 		~FactoryParameter()
 		{
 #ifdef DEBUG_PLUGINS
-			fprintf(stderr, "~FactoryParameter places configuredPlugin %s in unload query for %d seconds\n",
+			fprintf(stderr, "~FactoryParameter places configuredPlugin %s in unload query for %lld seconds\n",
 				configuredPlugin->getPlugName(), configuredPlugin->getReleaseDelay() / 1000000);
 #endif
 			FbLocalStatus ls;
@@ -694,6 +698,9 @@ namespace
 #endif
 	}
 
+	typedef HalfStaticArray<ConfiguredPlugin*, 16> DelayedDelete;
+	static GlobalPtr<DelayedDelete> delayedDelete;
+
 	int ConfiguredPlugin::release()
 	{
 		int x = --refCounter;
@@ -709,6 +716,15 @@ namespace
 				if (refCounter != 0)
 					return 1;
 
+				if (Why::timerThreadStopped() && !processingDelayedDelete && delayedDelete)
+				{
+					// delay delete
+					addRef();
+					delayedDelete->push(this);
+
+					return 1;
+				}
+
 				destroy();
 			}
 
@@ -721,6 +737,26 @@ namespace
 		return 1;
 	}
 
+	void ConfiguredPlugin::processDelayedDelete()
+	{
+		DelayedDelete& dd(delayedDelete);
+		MutexEnsureUnlock g(plugins->mutex, FB_FUNCTION);
+		g.enter();
+		for (unsigned n = 0; n < dd.getCount(); ++n)
+		{
+			ConfiguredPlugin* ptr = dd[n];
+			if (ptr)
+			{
+				g.leave();
+				ptr->processingDelayedDelete = true;
+				ptr->release();
+				g.enter();
+			}
+			dd[n] = nullptr;
+		}
+		delayedDelete->clear();
+	}
+
 	PluginModule* modules = NULL;
 
 	PluginModule* current = NULL;
@@ -1211,6 +1247,10 @@ void PluginManager::threadDetach()
 		modules->threadDetach();
 }
 
+void PluginManager::deleteDelayed()
+{
+	ConfiguredPlugin::processDelayedDelete();
+}
 
 }	// namespace Firebird
 

src/yvalve/PluginManager.h

@@ -55,6 +55,7 @@ class PluginManager : public AutoIface<IPluginManagerImpl<PluginManager, CheckSt
 	static void shutdown();
 	static void waitForType(unsigned int typeThatMustGoAway);
 	static void threadDetach();
+	static void deleteDelayed();
 };
 
 }	// namespace Firebird

src/yvalve/why.cpp

@@ -6880,7 +6880,10 @@ void Dispatcher::shutdown(CheckStatusWrapper* userStatus, unsigned int timeout,
 			}
 
 			if (hasThreads)
+			{
+				PluginManager::deleteDelayed();
 				continue;
+			}
 
 			Stack<YAttachment*, 64> attStack;
 			{
@@ -6910,6 +6913,7 @@ void Dispatcher::shutdown(CheckStatusWrapper* userStatus, unsigned int timeout,
 				attachment->release();
 			}
 
+			PluginManager::deleteDelayed();
 		}
 
 		// ... and wait for all providers to go away