Major plugin refactor and cleanup.

Switched to POCO library for unified platform/library interface.
Deprecated the external module API. It was creating more problems than solving.
Removed most built-in libraries in favor of system libraries for easier maintenance.
Cleaned and secured code with help from static analyzers.

vendor/POCO/Foundation/include/Poco/ThreadPool.h

@@ -0,0 +1,208 @@
+//
+// ThreadPool.h
+//
+// Library: Foundation
+// Package: Threading
+// Module:  ThreadPool
+//
+// Definition of the ThreadPool class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_ThreadPool_INCLUDED
+#define Foundation_ThreadPool_INCLUDED
+
+
+#include "Poco/Foundation.h"
+#include "Poco/Thread.h"
+#include "Poco/Mutex.h"
+#include <vector>
+
+
+namespace Poco {
+
+
+class Runnable;
+class PooledThread;
+
+
+class Foundation_API ThreadPool
+	/// A thread pool always keeps a number of threads running, ready
+	/// to accept work.
+	/// Creating and starting a threads can impose a significant runtime
+	/// overhead to an application. A thread pool helps to improve
+	/// the performance of an application by reducing the number
+	/// of threads that have to be created (and destroyed again).
+	/// Threads in a thread pool are re-used once they become
+	/// available again.
+	/// The thread pool always keeps a minimum number of threads
+	/// running. If the demans for threads increases, additional
+	/// threads are created. Once the demand for threads sinks
+	/// again, no-longer used threads are stopped and removed
+	/// from the pool.
+{
+public:
+	ThreadPool(int minCapacity = 2,
+		int maxCapacity = 16,
+		int idleTime = 60,
+		int stackSize = POCO_THREAD_STACK_SIZE);
+		/// Creates a thread pool with minCapacity threads.
+		/// If required, up to maxCapacity threads are created
+		/// a NoThreadAvailableException exception is thrown.
+		/// If a thread is running idle for more than idleTime seconds,
+		/// and more than minCapacity threads are running, the thread
+		/// is killed. Threads are created with given stack size.
+
+	ThreadPool(const std::string& name,
+		int minCapacity = 2,
+		int maxCapacity = 16,
+		int idleTime = 60,
+		int stackSize = POCO_THREAD_STACK_SIZE);
+		/// Creates a thread pool with the given name and minCapacity threads.
+		/// If required, up to maxCapacity threads are created
+		/// a NoThreadAvailableException exception is thrown.
+		/// If a thread is running idle for more than idleTime seconds,
+		/// and more than minCapacity threads are running, the thread
+		/// is killed. Threads are created with given stack size.
+
+	~ThreadPool();
+		/// Currently running threads will remain active
+		/// until they complete. 
+	
+	void addCapacity(int n);
+		/// Increases (or decreases, if n is negative)
+		/// the maximum number of threads.
+
+	int capacity() const;
+		/// Returns the maximum capacity of threads.
+
+	void setStackSize(int stackSize);
+		/// Sets the stack size for threads.
+		/// New stack size applies only for newly created threads.
+
+	int getStackSize() const;
+		/// Returns the stack size used to create new threads.
+
+	int used() const;
+		/// Returns the number of currently used threads.
+
+	int allocated() const;
+		/// Returns the number of currently allocated threads.
+
+	int available() const;
+		/// Returns the number available threads.
+
+	void start(Runnable& target);
+		/// Obtains a thread and starts the target.
+		/// Throws a NoThreadAvailableException if no more
+		/// threads are available.
+
+	void start(Runnable& target, const std::string& name);
+		/// Obtains a thread and starts the target.
+		/// Assigns the given name to the thread.
+		/// Throws a NoThreadAvailableException if no more
+		/// threads are available.
+
+	void startWithPriority(Thread::Priority priority, Runnable& target);
+		/// Obtains a thread, adjusts the thread's priority, and starts the target.
+		/// Throws a NoThreadAvailableException if no more
+		/// threads are available.
+
+	void startWithPriority(Thread::Priority priority, Runnable& target, const std::string& name);
+		/// Obtains a thread, adjusts the thread's priority, and starts the target.
+		/// Assigns the given name to the thread.
+		/// Throws a NoThreadAvailableException if no more
+		/// threads are available.
+
+	void stopAll();
+		/// Stops all running threads and waits for their completion.
+		///
+		/// Will also delete all thread objects.
+		/// If used, this method should be the last action before
+		/// the thread pool is deleted.
+		///
+		/// Note: If a thread fails to stop within 10 seconds 
+		/// (due to a programming error, for example), the
+		/// underlying thread object will not be deleted and
+		/// this method will return anyway. This allows for a
+		/// more or less graceful shutdown in case of a misbehaving
+		/// thread.
+
+	void joinAll();
+		/// Waits for all threads to complete.
+		///
+		/// Note that this will not actually join() the underlying
+		/// thread, but rather wait for the thread's runnables
+		/// to finish.
+
+	void collect();
+		/// Stops and removes no longer used threads from the
+		/// thread pool. Can be called at various times in an
+		/// application's life time to help the thread pool
+		/// manage its threads. Calling this method is optional,
+		/// as the thread pool is also implicitly managed in
+		/// calls to start(), addCapacity() and joinAll().
+
+	const std::string& name() const;
+		/// Returns the name of the thread pool,
+		/// or an empty string if no name has been
+		/// specified in the constructor.
+
+	static ThreadPool& defaultPool();
+		/// Returns a reference to the default
+		/// thread pool.
+
+protected:
+	PooledThread* getThread();
+	PooledThread* createThread();
+
+	void housekeep();
+
+private:
+	ThreadPool(const ThreadPool& pool);
+	ThreadPool& operator = (const ThreadPool& pool);
+
+	typedef std::vector<PooledThread*> ThreadVec;
+
+	std::string _name;
+	int _minCapacity;
+	int _maxCapacity;
+	int _idleTime;
+	int _serial;
+	int _age;
+	int _stackSize;
+	ThreadVec _threads;
+	mutable FastMutex _mutex;
+};
+
+
+//
+// inlines
+//
+inline void ThreadPool::setStackSize(int stackSize)
+{
+	_stackSize = stackSize;
+}
+
+
+inline int ThreadPool::getStackSize() const
+{
+	return _stackSize;
+}
+
+
+inline const std::string& ThreadPool::name() const
+{
+	return _name;
+}
+
+
+} // namespace Poco
+
+
+#endif // Foundation_ThreadPool_INCLUDED