chan.h

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/* -*- C -*- */
/*
 * Copyright (c) 2012-2020 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_CHAN_H__
#define __MOTR_LIB_CHAN_H__

#include "lib/tlist.h"
#include "lib/mutex.h"
#include "lib/time.h"
#include "lib/semaphore.h"
#include "addb2/histogram.h"

struct m0_chan;
struct m0_clink;
struct m0_chan_addb2;

typedef bool (*m0_chan_cb_t)(struct m0_clink *link);

struct m0_chan {
        struct m0_mutex      *ch_guard;
        struct m0_tl          ch_links;
        uint32_t              ch_waiters;
        struct m0_chan_addb2 *ch_addb2;
};

struct m0_clink {
        struct m0_chan     *cl_chan;
        m0_chan_cb_t        cl_cb;
        struct m0_clink    *cl_group;
        struct m0_tlink     cl_linkage;
        struct m0_semaphore cl_wait;
        bool                cl_is_oneshot;
        uint64_t            cl_magic;
};

M0_INTERNAL void m0_chan_init(struct m0_chan *chan, struct m0_mutex *ch_guard);
M0_INTERNAL void m0_chan_fini(struct m0_chan *chan);
M0_INTERNAL void m0_chan_fini_lock(struct m0_chan *chan);

M0_INTERNAL void m0_chan_signal(struct m0_chan *chan);

M0_INTERNAL void m0_chan_signal_lock(struct m0_chan *chan);

M0_INTERNAL void m0_chan_broadcast(struct m0_chan *chan);

M0_INTERNAL void m0_chan_broadcast_lock(struct m0_chan *chan);

M0_INTERNAL void m0_clink_signal(struct m0_clink *clink);

M0_INTERNAL bool m0_chan_has_waiters(struct m0_chan *chan);

M0_INTERNAL void m0_clink_init(struct m0_clink *link, m0_chan_cb_t cb);
M0_INTERNAL void m0_clink_fini(struct m0_clink *link);

M0_INTERNAL void m0_clink_attach(struct m0_clink *link,
                                 struct m0_clink *group, m0_chan_cb_t cb);

M0_INTERNAL void m0_clink_add(struct m0_chan *chan, struct m0_clink *link);

M0_INTERNAL void m0_clink_del(struct m0_clink *link);

M0_INTERNAL void m0_clink_add_lock(struct m0_chan *chan, struct m0_clink *link);

M0_INTERNAL void m0_clink_del_lock(struct m0_clink *link);

M0_INTERNAL bool m0_clink_is_armed(const struct m0_clink *link);

M0_INTERNAL void m0_clink_cleanup(struct m0_clink *link);

M0_INTERNAL void m0_clink_cleanup_locked(struct m0_clink *link);

M0_INTERNAL void m0_chan_wait(struct m0_clink *link);

M0_INTERNAL bool m0_chan_trywait(struct m0_clink *link);

M0_INTERNAL bool m0_chan_timedwait(struct m0_clink *link,
                                   const m0_time_t abs_timeout);

M0_INTERNAL void m0_chan_lock(struct m0_chan *ch);

M0_INTERNAL void m0_chan_unlock(struct m0_chan *ch);

M0_INTERNAL bool m0_chan_is_locked(const struct m0_chan *ch);

struct m0_chan_addb2 {
        uint64_t             ca_wait;
        uint64_t             ca_cb;
        struct m0_addb2_hist ca_wait_hist;
        struct m0_addb2_hist ca_cb_hist;
        struct m0_addb2_hist ca_queue_hist;
};

#endif /* __MOTR_LIB_CHAN_H__ */

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */