/*****************************************************************************\
 *  workq.h - declarations for work queue manager
 *****************************************************************************
 *  Copyright (C) SchedMD LLC.
 *
 *  This file is part of Slurm, a resource management program.
 *  For details, see <https://slurm.schedmd.com/>.
 *  Please also read the included file: DISCLAIMER.
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\*****************************************************************************/

#ifndef SLURMRESTD_WORKQ_H
#define SLURMRESTD_WORKQ_H

#include "src/common/list.h"

/*
 * Call back for generic work
 *
 * IN arg pointer to data for function
 */
typedef void (*work_func_t)(void *arg);

/* Opaque struct */
typedef struct workq_s workq_t;

/*
 * Initialize a new workq struct
 * IN count - number of workers to add
 * RET ptr to new workq struct
 */
extern workq_t *new_workq(int count);

/*
 * Stop all work (eventually) and reject new requests
 * This will block until all work is complete.
 */
extern void quiesce_workq(workq_t *workq);

/*
 * Free workq struct.
 * Will stop all workers (eventually).
 */
extern void free_workq(workq_t *workq);

/*
 * Add work to workq
 * IN workq - work queue to queue up work on
 * IN func - function pointer to run work
 * IN arg - arg to hand to function pointer
 * IN tag - tag used in logging this function
 * NOTE: never add a thread that will never return or free_workq() will never
 * return either.
 * RET SLURM_SUCCESS or error if workq already shutdown
 */
extern int workq_add_work(workq_t *workq, work_func_t func, void *arg,
			  const char *tag);

/*
 * Grab copy of the workq active count
 */
extern int workq_get_active(workq_t *workq);

#define FREE_NULL_WORKQ(_X)             \
	do {                            \
		if (_X)                 \
			free_workq(_X); \
		_X = NULL;              \
	} while (0)


/*
 * Get number of threads used by workq
 */
extern int get_workq_thread_count(const workq_t *workq);

#endif /* SLURMRESTD_WORKQ_H */
