path: root/src/OSSupport/IsThread.h

// IsThread.h

// Interfaces to the cIsThread class representing an OS-independent wrapper for a class that implements a thread.
// This class will eventually suupersede the old cThread class

/*
Usage:
To have a new thread, declare a class descending from cIsClass.
Then override its Execute() method to provide your thread processing.
In the descending class' constructor call the Start() method to start the thread once you're finished with initialization.
*/





#pragma once





class cIsThread
{
protected:
	/** This is the main thread entrypoint.
	This function, overloaded by the descendants, is called in the new thread. */
	virtual void Execute(void) = 0;

	/** The overriden Execute() method should check this value periodically and terminate if this is true. */
	std::atomic<bool> m_ShouldTerminate;

public:
	cIsThread(AString && a_ThreadName);
	virtual ~cIsThread();

	/** Starts the thread; returns without waiting for the actual start. */
	bool Start(void);

	/** Signals the thread to terminate and waits until it's finished. */
	void Stop(void);

	/** Waits for the thread to finish. Doesn't signalize the ShouldTerminate flag. */
	bool Wait(void);

	/** Returns true if the thread calling this function is the thread contained within this object. */
	bool IsCurrentThread(void) const { return std::this_thread::get_id() == m_Thread.get_id(); }

private:

	/** The name of the thread, used to aid debugging in IDEs which support named threads */
	AString m_ThreadName;

	/** The thread object which holds the created thread for later manipulation */
	std::thread m_Thread;

	/** The event that is used to wait with the thread's execution until the thread object is fully initialized.
	This prevents the IsCurrentThread() call to fail because of a race-condition where the thread starts before m_Thread has been fully assigned. */
	cEvent m_evtStart;

	/** Wrapper for Execute() that waits for the initialization event, to prevent race conditions in thread initialization. */
	void DoExecute(void);
} ;