mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
54 lines
1.5 KiB
54 lines
1.5 KiB
/* SPDX-License-Identifier: GPL-2.0+ */ |
|
/* |
|
* RCU-based infrastructure for lightweight reader-writer locking |
|
* |
|
* Copyright (c) 2015, Red Hat, Inc. |
|
* |
|
* Author: Oleg Nesterov <[email protected]> |
|
*/ |
|
|
|
#ifndef _LINUX_RCU_SYNC_H_ |
|
#define _LINUX_RCU_SYNC_H_ |
|
|
|
#include <linux/wait.h> |
|
#include <linux/rcupdate.h> |
|
|
|
/* Structure to mediate between updaters and fastpath-using readers. */ |
|
struct rcu_sync { |
|
int gp_state; |
|
int gp_count; |
|
wait_queue_head_t gp_wait; |
|
|
|
struct rcu_head cb_head; |
|
}; |
|
|
|
/** |
|
* rcu_sync_is_idle() - Are readers permitted to use their fastpaths? |
|
* @rsp: Pointer to rcu_sync structure to use for synchronization |
|
* |
|
* Returns true if readers are permitted to use their fastpaths. Must be |
|
* invoked within some flavor of RCU read-side critical section. |
|
*/ |
|
static inline bool rcu_sync_is_idle(struct rcu_sync *rsp) |
|
{ |
|
RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(), |
|
"suspicious rcu_sync_is_idle() usage"); |
|
return !READ_ONCE(rsp->gp_state); /* GP_IDLE */ |
|
} |
|
|
|
extern void rcu_sync_init(struct rcu_sync *); |
|
extern void rcu_sync_enter_start(struct rcu_sync *); |
|
extern void rcu_sync_enter(struct rcu_sync *); |
|
extern void rcu_sync_exit(struct rcu_sync *); |
|
extern void rcu_sync_dtor(struct rcu_sync *); |
|
|
|
#define __RCU_SYNC_INITIALIZER(name) { \ |
|
.gp_state = 0, \ |
|
.gp_count = 0, \ |
|
.gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \ |
|
} |
|
|
|
#define DEFINE_RCU_SYNC(name) \ |
|
struct rcu_sync name = __RCU_SYNC_INITIALIZER(name) |
|
|
|
#endif /* _LINUX_RCU_SYNC_H_ */
|
|
|