mirror of
https://git.proxmox.com/git/mirror_zfs.git
synced 2024-12-26 19:19:32 +03:00
f4b377415b
muck with #includes in existing Solaris style source to get it to find the right stuff. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@18 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
122 lines
2.3 KiB
C
122 lines
2.3 KiB
C
#ifndef _SPL_MUTEX_H
|
|
#define _SPL_MUTEX_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#include <linux/module.h>
|
|
#include <sys/types.h>
|
|
|
|
/* See the "Big Theory Statement" in solaris mutex.c.
|
|
*
|
|
* Spin mutexes apparently aren't needed by zfs so we assert
|
|
* if ibc is non-zero.
|
|
*
|
|
* Our impementation of adaptive mutexes aren't really adaptive.
|
|
* They go to sleep every time.
|
|
*/
|
|
|
|
#define MUTEX_DEFAULT 0
|
|
#define MUTEX_HELD(x) (mutex_owned(x))
|
|
|
|
#define KM_MAGIC 0x42424242
|
|
#define KM_POISON 0x84
|
|
|
|
typedef struct {
|
|
int km_magic;
|
|
char *km_name;
|
|
struct task_struct *km_owner;
|
|
struct semaphore km_sem;
|
|
} kmutex_t;
|
|
|
|
#undef mutex_init
|
|
static __inline__ void
|
|
mutex_init(kmutex_t *mp, char *name, int type, void *ibc)
|
|
{
|
|
BUG_ON(ibc != NULL); /* XXX - Spin mutexes not needed? */
|
|
BUG_ON(type != MUTEX_DEFAULT); /* XXX - Only default type supported? */
|
|
|
|
mp->km_magic = KM_MAGIC;
|
|
sema_init(&mp->km_sem, 1);
|
|
mp->km_owner = NULL;
|
|
mp->km_name = NULL;
|
|
|
|
if (name) {
|
|
mp->km_name = kmalloc(strlen(name) + 1, GFP_KERNEL);
|
|
if (mp->km_name)
|
|
strcpy(mp->km_name, name);
|
|
}
|
|
}
|
|
|
|
#undef mutex_destroy
|
|
static __inline__ void
|
|
mutex_destroy(kmutex_t *mp)
|
|
{
|
|
BUG_ON(mp->km_magic != KM_MAGIC);
|
|
|
|
if (mp->km_name)
|
|
kfree(mp->km_name);
|
|
|
|
memset(mp, KM_POISON, sizeof(*mp));
|
|
}
|
|
|
|
static __inline__ void
|
|
mutex_enter(kmutex_t *mp)
|
|
{
|
|
BUG_ON(mp->km_magic != KM_MAGIC);
|
|
down(&mp->km_sem); /* Will check in_atomic() for us */
|
|
BUG_ON(mp->km_owner != NULL);
|
|
mp->km_owner = current;
|
|
}
|
|
|
|
/* Return 1 if we acquired the mutex, else zero.
|
|
*/
|
|
static __inline__ int
|
|
mutex_tryenter(kmutex_t *mp)
|
|
{
|
|
int result;
|
|
|
|
BUG_ON(mp->km_magic != KM_MAGIC);
|
|
result = down_trylock(&mp->km_sem); /* returns 0 if acquired */
|
|
if (result == 0) {
|
|
BUG_ON(mp->km_owner != NULL);
|
|
mp->km_owner = current;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static __inline__ void
|
|
mutex_exit(kmutex_t *mp)
|
|
{
|
|
BUG_ON(mp->km_magic != KM_MAGIC);
|
|
BUG_ON(mp->km_owner != current);
|
|
mp->km_owner = NULL;
|
|
up(&mp->km_sem);
|
|
}
|
|
|
|
/* Return 1 if mutex is held by current process, else zero.
|
|
*/
|
|
static __inline__ int
|
|
mutex_owned(kmutex_t *mp)
|
|
{
|
|
BUG_ON(mp->km_magic != KM_MAGIC);
|
|
return (mp->km_owner == current);
|
|
}
|
|
|
|
/* Return owner if mutex is owned, else NULL.
|
|
*/
|
|
static __inline__ kthread_t *
|
|
mutex_owner(kmutex_t *mp)
|
|
{
|
|
BUG_ON(mp->km_magic != KM_MAGIC);
|
|
return mp->km_owner;
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* _SPL_MUTEX_H */
|