d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Replace direct atomic operation for the file refcount witht the

Browse Source 
refcount interface.
It also introduces the correct usage of memory barriers, as sometimes
fdrop() and fhold() are used with shared locks, which don't use any
release barrier.
This commit is contained in:
Attilio Rao 2008-05-25 14:57:43 +00:00
parent 0e72a03405
commit 258f4727f1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=179305
2 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/kern/kern_descrip.c
View File

@ -1449,9 +1449,9 @@ falloc(struct thread *td, struct file **resultfp, int *resultfd)
* descriptor to the list of open files at that point, otherwise
* put it at the front of the list of open files.
*/
fp->f_count = 1;
refcount_init(&fp->f_count, 1);
if (resultfp)
fp->f_count++;
fhold(fp);
fp->f_cred = crhold(td->td_ucred);
fp->f_ops = &badfileops;
fp->f_data = NULL;

8
sys/sys/file.h
View File

@ -39,6 +39,7 @@
#include <sys/unistd.h>
#else
#include <sys/queue.h>
#include <sys/refcount.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
@ -116,7 +117,7 @@ struct file {
short f_type; /* descriptor type */
short f_vnread_flags; /* (f) Sleep lock for f_offset */
volatile u_int f_flag; /* see fcntl.h */
volatile int f_count; /* reference count */
volatile u_int f_count; /* reference count */
/*
* DTYPE_VNODE specific fields.
*/
@ -196,9 +197,10 @@ int fgetvp_write(struct thread *td, int fd, struct vnode **vpp);
int fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp);
void fputsock(struct socket *sp);
#define fhold(fp) atomic_add_int(&(fp)->f_count, 1)
#define fhold(fp) \
(refcount_acquire(&(fp)->f_count))
#define fdrop(fp, td) \
(atomic_fetchadd_int(&(fp)->f_count, -1) <= 1 ? _fdrop((fp), (td)) : 0)
(refcount_release(&(fp)->f_count) ? _fdrop((fp), (td)) : 0)
static __inline fo_rdwr_t fo_read;
static __inline fo_rdwr_t fo_write;