/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*! \file */

#include <config.h>

#include <stdbool.h>

#include <isc/mem.h>

#include <isc/random.h>

#include <isc/taskpool.h>

#include <isc/util.h>

/***

 *** Types.

 ***/

struct isc_taskpool {

	isc_mem_t *			mctx;

	isc_taskmgr_t *			tmgr;

	unsigned int			ntasks;

	unsigned int			quantum;

	isc_task_t **			tasks;

};

/***

 *** Functions.

 ***/

static isc_result_t

alloc_pool(isc_taskmgr_t *tmgr, isc_mem_t *mctx, unsigned int ntasks,

	   unsigned int quantum, isc_taskpool_t **poolp)

{

	isc_taskpool_t *pool;

	unsigned int i;

	pool = isc_mem_get(mctx, sizeof(*pool));

	if (pool == NULL)

		return (ISC_R_NOMEMORY);

	pool->mctx = NULL;

	isc_mem_attach(mctx, &pool->mctx);

	pool->ntasks = ntasks;

	pool->quantum = quantum;

	pool->tmgr = tmgr;

	pool->tasks = isc_mem_get(mctx, ntasks * sizeof(isc_task_t *));

	if (pool->tasks == NULL) {

		isc_mem_putanddetach(&pool->mctx, pool, sizeof(*pool));

		return (ISC_R_NOMEMORY);

	}

	for (i = 0; i < ntasks; i++)

		pool->tasks[i] = NULL;

	*poolp = pool;

	return (ISC_R_SUCCESS);

}

isc_result_t

isc_taskpool_create(isc_taskmgr_t *tmgr, isc_mem_t *mctx,

		    unsigned int ntasks, unsigned int quantum,

		    isc_taskpool_t **poolp)

{

	unsigned int i;

	isc_taskpool_t *pool = NULL;

	isc_result_t result;

	INSIST(ntasks > 0);

	/* Allocate the pool structure */

	result = alloc_pool(tmgr, mctx, ntasks, quantum, &pool);

	if (result != ISC_R_SUCCESS)

		return (result);

	/* Create the tasks */

	for (i = 0; i < ntasks; i++) {

		result = isc_task_create(tmgr, quantum, &pool->tasks[i]);

		if (result != ISC_R_SUCCESS) {

			isc_taskpool_destroy(&pool);

			return (result);

		}

		isc_task_setname(pool->tasks[i], "taskpool", NULL);

	}

	*poolp = pool;

	return (ISC_R_SUCCESS);

}

void

isc_taskpool_gettask(isc_taskpool_t *pool, isc_task_t **targetp) {

	uint32_t i;

	isc_random_get(&i);

	isc_task_attach(pool->tasks[i % pool->ntasks], targetp);

}

int

isc_taskpool_size(isc_taskpool_t *pool) {

	REQUIRE(pool != NULL);

	return (pool->ntasks);

}

isc_result_t

isc_taskpool_expand(isc_taskpool_t **sourcep, unsigned int size,

		    isc_taskpool_t **targetp)

{

	isc_result_t result;

	isc_taskpool_t *pool;

	REQUIRE(sourcep != NULL && *sourcep != NULL);

	REQUIRE(targetp != NULL && *targetp == NULL);

	pool = *sourcep;

	if (size > pool->ntasks) {

		isc_taskpool_t *newpool = NULL;

		unsigned int i;

		/* Allocate a new pool structure */

		result = alloc_pool(pool->tmgr, pool->mctx, size,

				    pool->quantum, &newpool);

		if (result != ISC_R_SUCCESS)

			return (result);

		/* Copy over the tasks from the old pool */

		for (i = 0; i < pool->ntasks; i++) {

			newpool->tasks[i] = pool->tasks[i];

			pool->tasks[i] = NULL;

		}

		/* Create new tasks */

		for (i = pool->ntasks; i < size; i++) {

			result = isc_task_create(pool->tmgr, pool->quantum,

						 &newpool->tasks[i]);

			if (result != ISC_R_SUCCESS) {

				isc_taskpool_destroy(&newpool);

				return (result);

			}

			isc_task_setname(newpool->tasks[i], "taskpool", NULL);

		}

		isc_taskpool_destroy(&pool);

		pool = newpool;

	}

	*sourcep = NULL;

	*targetp = pool;

	return (ISC_R_SUCCESS);

}

void

isc_taskpool_destroy(isc_taskpool_t **poolp) {

	unsigned int i;

	isc_taskpool_t *pool = *poolp;

	for (i = 0; i < pool->ntasks; i++) {

		if (pool->tasks[i] != NULL)

			isc_task_detach(&pool->tasks[i]);

	}

	isc_mem_put(pool->mctx, pool->tasks,

		    pool->ntasks * sizeof(isc_task_t *));

	isc_mem_putanddetach(&pool->mctx, pool, sizeof(*pool));

	*poolp = NULL;

}

void

isc_taskpool_setprivilege(isc_taskpool_t *pool, bool priv) {

	unsigned int i;

	REQUIRE(pool != NULL);

	for (i = 0; i < pool->ntasks; i++) {

		if (pool->tasks[i] != NULL)

			isc_task_setprivilege(pool->tasks[i], priv);

	}

}