Use kinfo_getfile to implement fdwalk on FreeBSD.
Commit Message
kinfo_getfile() requires a couple of system calls to fetch the list of
open file descriptors. This can be much cheaper than invoking fstat
on all of the values from 0 to the open file resource limit maximum.
gdb/ChangeLog:
* common/filestuff.c [HAVE_KINFO_GETFILE]: Include headers.
(fdwalk) [HAVE_KINFO_GETFILE]: Use kinfo_getfile.
---
gdb/ChangeLog | 5 +++++
gdb/common/filestuff.c | 26 ++++++++++++++++++++++++++
2 files changed, 31 insertions(+)
Comments
>>>>> "John" == John Baldwin <jhb@FreeBSD.org> writes:
John> kinfo_getfile() requires a couple of system calls to fetch the list of
John> open file descriptors. This can be much cheaper than invoking fstat
John> on all of the values from 0 to the open file resource limit maximum.
John> gdb/ChangeLog:
John> * common/filestuff.c [HAVE_KINFO_GETFILE]: Include headers.
John> (fdwalk) [HAVE_KINFO_GETFILE]: Use kinfo_getfile.
Thanks.
John> +#ifdef HAVE_KINFO_GETFILE
John> + gdb::unique_xmalloc_ptr<struct kinfo_file> fdtbl;
John> + int nfd;
John> + fdtbl.reset (kinfo_getfile (getpid (), &nfd));
I think this should be combined with the declaration; no need to call
reset.
This is ok with that change.
Tom
On 11/30/2018 10:15 PM, Tom Tromey wrote:
> John> +#ifdef HAVE_KINFO_GETFILE
> John> + gdb::unique_xmalloc_ptr<struct kinfo_file> fdtbl;
> John> + int nfd;
> John> + fdtbl.reset (kinfo_getfile (getpid (), &nfd));
>
> I think this should be combined with the declaration; no need to call
> reset.
If you want, you can also use the array-version of unique_ptr
and eliminate some variables:
int nfd;
gdb::unique_xmalloc_ptr<struct kinfo_file[]> fdtbl
(kinfo_getfile (getpid (), &nfd));
if (fdtbl != NULL)
{
for (int i = 0; i < nfd; i++)
{
if (fdtbl[i]->kf_fd >= 0)
{
int result = func (arg, fdtbl[i]->kf_fd);
if (result != 0)
return result;
}
}
return 0;
}
Thanks,
Pedro Alves
On 11/30/18 2:39 PM, Pedro Alves wrote:
> On 11/30/2018 10:15 PM, Tom Tromey wrote:
>
>> John> +#ifdef HAVE_KINFO_GETFILE
>> John> + gdb::unique_xmalloc_ptr<struct kinfo_file> fdtbl;
>> John> + int nfd;
>> John> + fdtbl.reset (kinfo_getfile (getpid (), &nfd));
>>
>> I think this should be combined with the declaration; no need to call
>> reset.
> If you want, you can also use the array-version of unique_ptr
> and eliminate some variables:
>
> int nfd;
> gdb::unique_xmalloc_ptr<struct kinfo_file[]> fdtbl
> (kinfo_getfile (getpid (), &nfd));
> if (fdtbl != NULL)
> {
> for (int i = 0; i < nfd; i++)
> {
> if (fdtbl[i]->kf_fd >= 0)
> {
> int result = func (arg, fdtbl[i]->kf_fd);
> if (result != 0)
> return result;
> }
> }
> return 0;
> }
Thanks. This is what I pushed (modulo using fdtbl[i]. rather than
fdtbl[i]->).
@@ -1,3 +1,8 @@
+2018-11-30 John Baldwin <jhb@FreeBSD.org>
+
+ * common/filestuff.c [HAVE_KINFO_GETFILE]: Include headers.
+ (fdwalk) [HAVE_KINFO_GETFILE]: Use kinfo_getfile.
+
2018-11-30 John Baldwin <jhb@FreeBSD.org>
* fbsd-nat.c [__FreeBSD_version >= 700009] (USE_SIGINFO): Macro
@@ -36,6 +36,11 @@
#define HAVE_SOCKETS 1
#endif
+#ifdef HAVE_KINFO_GETFILE
+#include <sys/user.h>
+#include <libutil.h>
+#endif
+
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif /* HAVE_SYS_RESOURCE_H */
@@ -108,6 +113,27 @@ fdwalk (int (*func) (void *, int), void *arg)
}
/* We may fall through to the next case. */
#endif
+#ifdef HAVE_KINFO_GETFILE
+ gdb::unique_xmalloc_ptr<struct kinfo_file> fdtbl;
+ int nfd;
+ fdtbl.reset (kinfo_getfile (getpid (), &nfd));
+ if (fdtbl != NULL)
+ {
+ int result = 0;
+ struct kinfo_file *kf = fdtbl.get ();
+ for (int i = 0; i < nfd; i++, kf++)
+ {
+ if (kf->kf_fd >= 0)
+ {
+ result = func (arg, kf->kf_fd);
+ if (result != 0)
+ break;
+ }
+ }
+ return result;
+ }
+ /* We may fall through to the next case. */
+#endif
{
int max, fd;