Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add rw_obj_*() functions to mirror the existing mutex functions.

Browse Source 
Proposed on tech-kern quite some time ago.
This commit is contained in:
ad 2009-04-19 08:36:04 +00:00
parent 0350114585
commit a8bd3c39aa
2 changed files with 106 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

103
sys/kern/kern_rwlock.c
View File

@ -1,7 +1,7 @@
/* $NetBSD: kern_rwlock.c,v 1.28 2008/07/29 16:13:39 thorpej Exp $ */
/* $NetBSD: kern_rwlock.c,v 1.29 2009/04/19 08:36:04 ad Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007, 2008 The NetBSD Foundation, Inc.
* Copyright (c) 2002, 2006, 2007, 2008, 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
@ -38,7 +38,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_rwlock.c,v 1.28 2008/07/29 16:13:39 thorpej Exp $");
__KERNEL_RCSID(0, "$NetBSD: kern_rwlock.c,v 1.29 2009/04/19 08:36:04 ad Exp $");
#define __RWLOCK_PRIVATE
@ -161,6 +161,18 @@ syncobj_t rw_syncobj = {
rw_owner,
};
/* Mutex cache */
#define RW_OBJ_MAGIC 0x85d3c85d
struct krwobj {
krwlock_t ro_lock;
u_int ro_magic;
u_int ro_refcnt;
};
static int rw_obj_ctor(void *, void *, int);
static pool_cache_t rw_obj_cache;
/*
* rw_dump:
*
@ -775,3 +787,88 @@ rw_owner(wchan_t obj)
return (void *)(owner & RW_THREAD);
}
/*
* rw_obj_init:
*
* Initialize the rw object store.
*/
void
rw_obj_init(void)
{
rw_obj_cache = pool_cache_init(sizeof(struct krwobj),
coherency_unit, 0, 0, "rwlock", NULL, IPL_NONE, rw_obj_ctor,
NULL, NULL);
}
/*
* rw_obj_ctor:
*
* Initialize a new lock for the cache.
*/
static int
rw_obj_ctor(void *arg, void *obj, int flags)
{
struct krwobj * ro = obj;
ro->ro_magic = RW_OBJ_MAGIC;
return 0;
}
/*
* rw_obj_alloc:
*
* Allocate a single lock object.
*/
krwlock_t *
rw_obj_alloc(void)
{
struct krwobj *ro;
ro = pool_cache_get(rw_obj_cache, PR_WAITOK);
rw_init(&ro->ro_lock);
ro->ro_refcnt = 1;
return (krwlock_t *)ro;
}
/*
* rw_obj_hold:
*
* Add a single reference to a lock object. A reference to the object
* must already be held, and must be held across this call.
*/
void
rw_obj_hold(krwlock_t *lock)
{
struct krwobj *ro = (struct krwobj *)lock;
KASSERT(ro->ro_magic == RW_OBJ_MAGIC);
KASSERT(ro->ro_refcnt > 0);
atomic_inc_uint(&ro->ro_refcnt);
}
/*
* rw_obj_free:
*
* Drop a reference from a lock object. If the last reference is being
* dropped, free the object and return true. Otherwise, return false.
*/
bool
rw_obj_free(krwlock_t *lock)
{
struct krwobj *ro = (struct krwobj *)lock;
KASSERT(ro->ro_magic == RW_OBJ_MAGIC);
KASSERT(ro->ro_refcnt > 0);
if (atomic_dec_uint_nv(&ro->ro_refcnt) > 0) {
return false;
}
rw_destroy(&ro->ro_lock);
pool_cache_put(rw_obj_cache, ro);
return true;
}

7
sys/sys/rwlock.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: rwlock.h,v 1.6 2008/04/28 20:24:11 martin Exp $ */
/* $NetBSD: rwlock.h,v 1.7 2009/04/19 08:36:04 ad Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@ -107,6 +107,11 @@ int rw_lock_held(krwlock_t *);
void rw_enter(krwlock_t *, const krw_t);
void rw_exit(krwlock_t *);
void rw_obj_init(void);
krwlock_t *rw_obj_alloc(void);
void rw_obj_hold(krwlock_t *);
bool rw_obj_free(krwlock_t *);
#endif /* _KERNEL */
#endif /* _SYS_RWLOCK_H_ */