//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2008 - 2010 Greenplum, Inc.
//
//	@filename:
//		IWorker.h
//
//	@doc:
//		Interface class to worker; broken into interface and implementation
//		to avoid cyclic dependencies between worker, list, etc.
//		The Worker abstraction contains only components needed to schedule,
//		execute, and abort tasks; no task specific configuration such as
//		output streams is contained in Worker;
//---------------------------------------------------------------------------
#ifndef GPOS_IWorker_H
#define GPOS_IWorker_H

#include "gpos/common/CStackObject.h"
#include "gpos/types.h"

#define GPOS_CHECK_ABORT (IWorker::CheckAbort(__FILE__, __LINE__))

#define GPOS_CHECK_STACK_SIZE                         \
	do                                                \
	{                                                 \
		if (NULL != IWorker::Self())                  \
		{                                             \
			(void) IWorker::Self()->CheckStackSize(); \
		}                                             \
	} while (0)


#define GPOS_CHECK_ABORT_MAX_INTERVAL_MSEC (ULONG(1500))

namespace gpos
{
// prototypes
class ITask;
class CWorkerId;

//---------------------------------------------------------------------------
//	@class:
//		IWorker
//
//	@doc:
//		Interface to abstract scheduling primitive such as threads;
//
//---------------------------------------------------------------------------
class IWorker : public CStackObject
{
private:
	// check for abort request
	virtual void CheckForAbort(const CHAR *, ULONG) = 0;

public:
	IWorker(const IWorker &) = delete;

	// dummy ctor
	IWorker() = default;

	// dummy dtor
	virtual ~IWorker() = default;

	// accessors
	virtual ULONG_PTR GetStackStart() const = 0;
	virtual ITask *GetTask() = 0;

	// stack check
	virtual BOOL CheckStackSize(ULONG request = 0) const = 0;

	// lookup worker in worker pool manager
	static IWorker *Self();

	// check for aborts
	static void CheckAbort(const CHAR *file, ULONG line_num);

};	// class IWorker
}  // namespace gpos

#endif	// !GPOS_IWorker_H

// EOF