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/*
* Copyright (c) 2017-2018 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* Minimalist publish-subscribe mechanism.
*/
#ifndef KERN_BULLETIN_H
#define KERN_BULLETIN_H
#include <stdint.h>
#include <kern/macros.h>
#include <kern/work.h>
/*
* Type for bulletin notification functions.
*
* The value is passed from the publisher unmodified, and can safely be
* cast into a pointer. Notification functions run in the context of the
* publisher.
*/
typedef void (*bulletin_notif_fn_t)(uintptr_t value, void *arg);
#include <kern/bulletin_i.h>
struct bulletin;
/*
* Bulletin subscriber.
*/
struct bulletin_sub;
void bulletin_init(struct bulletin *bulletin);
/*
* Subscribe to a bulletin.
*
* Once subscribed, the notification function is called with its argument
* each time the bulletin is published.
*/
void bulletin_subscribe(struct bulletin *bulletin, struct bulletin_sub *sub,
bulletin_notif_fn_t notif_fn, void *arg);
/*
* Unsubscribe from a bulletin.
*
* On return, the subscriber notification function may not be called any more.
*
* This function synchronizes with RCU.
*/
void bulletin_unsubscribe(struct bulletin *bulletin, struct bulletin_sub *sub);
/*
* Publish a bulletin.
*
* All subscribers are notified by calling their notification function, with
* the given value passed unmodified.
*/
void bulletin_publish(struct bulletin *bulletin, uintptr_t value);
#endif /* KERN_BULLETIN_H */
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