thread_pool.h

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/* -*- C -*- */
/*
 * Copyright (c) 2015-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */


#pragma once

#ifndef __MOTR_LIB_THREAD_POOL_H__
#define __MOTR_LIB_THREAD_POOL_H__

#include "lib/queue.h"
#include "lib/mutex.h"
#include "lib/thread.h"
#include "lib/semaphore.h"

/* pool */

struct m0_parallel_queue_link;
struct m0_parallel_queue;

struct m0_parallel_pool {
        struct m0_semaphore            pp_sync;
        struct m0_semaphore            pp_ready;
        bool                           pp_done;

        int                          (*pp_process)(void *job);
        struct m0_thread              *pp_threads;
        int                            pp_thread_nr;

        struct m0_parallel_queue      *pp_queue;
        struct m0_parallel_queue_link *pp_qlinks;
        int                            pp_qlinks_nr;

        int                            pp_state;
        int                            pp_next_rc;
};

M0_INTERNAL int m0_parallel_pool_init(struct m0_parallel_pool *pool,
                                      int thread_nr, int qlinks_nr);
M0_INTERNAL void m0_parallel_pool_fini(struct m0_parallel_pool *pool);
M0_INTERNAL int  m0_parallel_pool_job_add(struct m0_parallel_pool *pool,
                                          void *job);
M0_INTERNAL int  m0_parallel_pool_wait(struct m0_parallel_pool *pool);
M0_INTERNAL void m0_parallel_pool_start(struct m0_parallel_pool *pool,
                                        int (*process)(void *job));
M0_INTERNAL void m0_parallel_pool_terminate_wait(struct m0_parallel_pool *pool);
M0_INTERNAL int  m0_parallel_pool_rc_next(struct m0_parallel_pool *pool,
                                          void **job, int *rc);

/* parallel for macro */

#define M0_PARALLEL_FOR(name, pool, list, process)                      \
({                                                                      \
        int rc = -EINVAL;                                               \
        typeof (name ## _tlist_head(NULL)) obj;                         \
        m0_tl_for(name, list, obj) {                                    \
                rc = m0_parallel_pool_job_add(pool, obj);               \
                if (rc == -EFBIG) {                                     \
                        m0_parallel_pool_start(pool, process);          \
                        rc = m0_parallel_pool_wait(pool);               \
                        if (rc != 0)                                    \
                                break;                                  \
                        rc = m0_parallel_pool_job_add(pool, obj);       \
                        M0_POST(rc == 0);                               \
                }                                                       \
        } m0_tl_endfor;                                                 \
        if (rc == 0) {                                                  \
                m0_parallel_pool_start(pool, process);                  \
                rc = m0_parallel_pool_wait(pool);                       \
        }                                                               \
        (rc);                                                           \
})

#endif /* __MOTR_LIB_THREAD_POOL_H__ */

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */
/*
 * vim: tabstop=8 shiftwidth=8 noexpandtab textwidth=80 nowrap
 */