Do all sound decoding in *one* background thread, instead of one thread per decoder.

BBGE/MT.h

@@ -0,0 +1,117 @@
+#ifndef BBGE_MT_H
+#define BBGE_MT_H
+
+#include <cstddef>
+#include <queue>
+#include <map>
+
+class Lockable
+{
+public:
+	Lockable();
+	virtual ~Lockable();
+	void lock();
+	void unlock();
+
+protected:
+	inline void *mutex() { return _mtx; }
+
+private:
+	void *_mtx;
+};
+
+class Waitable : public Lockable
+{
+public:
+	Waitable();
+	virtual ~Waitable();
+	void wait(); // releases the associated lock while waiting
+	void signal(); // signal a single waiting thread
+	void broadcast(); // signal all waiting threads
+
+private:
+	void *_cond;
+};
+
+class MTGuard
+{
+public:
+	MTGuard(Lockable& x) : _obj(&x) { _obj->lock(); }
+	MTGuard(Lockable* x) : _obj(x)  { _obj->lock(); }
+	~MTGuard() { _obj->unlock(); }
+	Lockable *_obj;
+};
+
+template <typename T> class BlockingQueue : public Waitable
+{
+public:
+	void push(const T& e)
+	{
+		lock();
+		_q.push(e);
+		unlock();
+		signal();
+	}
+	bool pop(T& e) // blocks if empty
+	{
+		lock();
+		while(_q.empty())
+			wait();
+		e = _q.front();
+		_q.pop();
+		unlock();
+		return true;
+	}
+private:
+	std::queue<T> _q;
+};
+
+template <typename T> class LockedQueue : public Lockable
+{
+public:
+	void push(const T& e)
+	{
+		lock();
+		_q.push(e);
+		unlock();
+	}
+	bool pop(T& e) // continues if empty
+	{
+		lock();
+		if(_q.empty())
+		{
+			unlock();
+			return false;
+		}
+		e = _q.front();
+		_q.pop();
+		unlock();
+		return true;
+	}
+	bool empty()
+	{
+		lock();
+		bool e = _q.empty();
+		unlock();
+		return e;
+	}
+	bool popIfPossible(T& e)
+	{
+		lock();
+		if(!_q.empty())
+		{
+			e = _q.front();
+			_q.pop();
+			unlock();
+			return true;
+		}
+		unlock();
+		return false;
+	}
+
+private:
+	std::queue<T> _q;
+};
+
+
+#endif