#ifndef __QUEUE_INCLUDED
#define __QUEUE_INCLUDED

#include <pthread.h>

typedef void (*process_func_t)( void *);

typedef struct {
	void *			_data;
	process_func_t	_process;
	volatile int	_done;

	pthread_mutex_t	_elem_lock;
} queue_elem_t;

typedef struct {
	size_t			_queue_size;
	queue_elem_t **	_queue;
	volatile size_t	_head, _tail, _next, _size;

	volatile int	_quit;
	process_func_t	_reap;
	volatile int	_last;

	pthread_mutex_t	_queue_lock;
	pthread_cond_t	_queue_insert, _queue_remove;
	pthread_cond_t	_elem_done;

	size_t			_workers;
	pthread_t *		_tid_workers;
	pthread_t		_tid_reaper;
} queue_t;

/*
	queue_insert( queue_t *, process_func_t func, void * data) 
		inserts a job into the queue; executes: func( data)
*/
void queue_insert( queue_t *, process_func_t, void *);

/*
	queue_insert_last( queue_t *); same as queue_insert( queue_t *, NULL, NULL)
*/
void queue_insert_last( queue_t *);

/*
	queue_wait_last( queue_t *)
		waits for a (NULL,NULL) job to be processed

	XXX: queue_insert resets the last flag; 
*/
void queue_wait_last( queue_t *);

/*
	queue_create( size_t queue_size, size_t workers, process_func_t reaper)
	
	creates a queue of size #queue_size with #workers workers
	and calls reaper( job.data) for each enqueued job when done
	and in sequence

	returns: queue_t * on success; NULL on error;
*/
queue_t * queue_create( size_t, size_t, process_func_t);

/*
	queue_destruct( queue_t *)

	frees resources allocated by queue_create;
*/
void queue_destruct( queue_t *);

#endif