Re: Need some help with the RBD Java bindings
On Wed, Aug 21, 2013 at 11:20 PM, Wido den Hollander wrote: > > Yes, seems like a good thing to do. I wasn't sure myself when I was writing > the bindings on how the packaging should be. I'm not entirely sure either. With JNI it's pretty simple, but JNA introduces all sorts of additional classes. Do you know of any large projects using JNA? It'd be nice to find some references to examine. > One of the things I haven't tested thoroughly enough is if you as a user of > the bindings are able to crash the JVM. Since that should never happen. I think that JNA is safe in that it will prevent itself from being used incorrectly, but I don't think anything would prevent someone from say creating a pointer off into space with JNA and then passing it to a external library that would dereference it. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Need some help with the RBD Java bindings
On 08/21/2013 09:47 PM, Noah Watkins wrote:
Wido,
How would you feel about creating two RbdSnapInfo objects. The first
would be something like ceph.rbd.RbdSnapInfo and the second would be
ceph.rbd.jna.RbdSnapInfo. The former is what will be exposed through
the API, and the later is used only internally. That should address
the hacky-ness of my snap listing fix: just create a copy of the
SnapInfo into the public struct. it also means we can avoid exposing
users to JNA structures.
Yes, seems like a good thing to do. I wasn't sure myself when I was
writing the bindings on how the packaging should be.
One of the things I haven't tested thoroughly enough is if you as a user
of the bindings are able to crash the JVM. Since that should never happen.
Wido
On Wed, Aug 21, 2013 at 5:11 AM, Wido den Hollander wrote:
On 08/20/2013 11:26 PM, Noah Watkins wrote:
Wido,
I pushed up a patch to
https://github.com/ceph/rados-java/commit/ca16d82bc5b596620609880e429ec9f4eaa4d5ce
That includes a fix for this problem. The fix is a bit hacky, but the
tests pass now. I included more details about the hack in the code.
I see. Works like a charm for me now. I'll do some further testing with
CloudStack.
Wido
On Thu, Aug 15, 2013 at 9:57 AM, Noah Watkins
wrote:
On Thu, Aug 15, 2013 at 8:51 AM, Wido den Hollander
wrote:
public List snapList() throws RbdException {
IntByReference numSnaps = new IntByReference(16);
PointerByReference snaps = new PointerByReference();
List list = new ArrayList();
RbdSnapInfo snapInfo, snapInfos[];
while (true) {
int r = rbd.rbd_snap_list(this.getPointer(), snaps, numSnaps);
I think you need to allocate the memory for `snaps` yourself. Here is
the RBD wrapper for Python which does that:
self.snaps = (rbd_snap_info_t * num_snaps.value)()
ret = self.librbd.rbd_snap_list(image.image, byref(self.snaps),
byref(num_snaps))
- Noah
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Re: Need some help with the RBD Java bindings
Wido,
How would you feel about creating two RbdSnapInfo objects. The first
would be something like ceph.rbd.RbdSnapInfo and the second would be
ceph.rbd.jna.RbdSnapInfo. The former is what will be exposed through
the API, and the later is used only internally. That should address
the hacky-ness of my snap listing fix: just create a copy of the
SnapInfo into the public struct. it also means we can avoid exposing
users to JNA structures.
On Wed, Aug 21, 2013 at 5:11 AM, Wido den Hollander wrote:
> On 08/20/2013 11:26 PM, Noah Watkins wrote:
>>
>> Wido,
>>
>> I pushed up a patch to
>>
>>
>> https://github.com/ceph/rados-java/commit/ca16d82bc5b596620609880e429ec9f4eaa4d5ce
>>
>> That includes a fix for this problem. The fix is a bit hacky, but the
>> tests pass now. I included more details about the hack in the code.
>>
>
> I see. Works like a charm for me now. I'll do some further testing with
> CloudStack.
>
> Wido
>
>> On Thu, Aug 15, 2013 at 9:57 AM, Noah Watkins
>> wrote:
>>>
>>> On Thu, Aug 15, 2013 at 8:51 AM, Wido den Hollander
>>> wrote:
public List snapList() throws RbdException {
IntByReference numSnaps = new IntByReference(16);
PointerByReference snaps = new PointerByReference();
List list = new ArrayList();
RbdSnapInfo snapInfo, snapInfos[];
while (true) {
int r = rbd.rbd_snap_list(this.getPointer(), snaps, numSnaps);
>>>
>>>
>>> I think you need to allocate the memory for `snaps` yourself. Here is
>>> the RBD wrapper for Python which does that:
>>>
>>>self.snaps = (rbd_snap_info_t * num_snaps.value)()
>>>ret = self.librbd.rbd_snap_list(image.image, byref(self.snaps),
>>> byref(num_snaps))
>>>
>>> - Noah
>>
>> --
>>
>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
> --
> Wido den Hollander
> 42on B.V.
>
> Phone: +31 (0)20 700 9902
> Skype: contact42on
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Re: Need some help with the RBD Java bindings
On 08/20/2013 11:26 PM, Noah Watkins wrote:
Wido,
I pushed up a patch to
https://github.com/ceph/rados-java/commit/ca16d82bc5b596620609880e429ec9f4eaa4d5ce
That includes a fix for this problem. The fix is a bit hacky, but the
tests pass now. I included more details about the hack in the code.
I see. Works like a charm for me now. I'll do some further testing with
CloudStack.
Wido
On Thu, Aug 15, 2013 at 9:57 AM, Noah Watkins wrote:
On Thu, Aug 15, 2013 at 8:51 AM, Wido den Hollander wrote:
public List snapList() throws RbdException {
IntByReference numSnaps = new IntByReference(16);
PointerByReference snaps = new PointerByReference();
List list = new ArrayList();
RbdSnapInfo snapInfo, snapInfos[];
while (true) {
int r = rbd.rbd_snap_list(this.getPointer(), snaps, numSnaps);
I think you need to allocate the memory for `snaps` yourself. Here is
the RBD wrapper for Python which does that:
self.snaps = (rbd_snap_info_t * num_snaps.value)()
ret = self.librbd.rbd_snap_list(image.image, byref(self.snaps),
byref(num_snaps))
- Noah
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--
Wido den Hollander
42on B.V.
Phone: +31 (0)20 700 9902
Skype: contact42on
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Re: Need some help with the RBD Java bindings
Wido,
I pushed up a patch to
https://github.com/ceph/rados-java/commit/ca16d82bc5b596620609880e429ec9f4eaa4d5ce
That includes a fix for this problem. The fix is a bit hacky, but the
tests pass now. I included more details about the hack in the code.
On Thu, Aug 15, 2013 at 9:57 AM, Noah Watkins wrote:
> On Thu, Aug 15, 2013 at 8:51 AM, Wido den Hollander wrote:
>>
>> public List snapList() throws RbdException {
>> IntByReference numSnaps = new IntByReference(16);
>> PointerByReference snaps = new PointerByReference();
>> List list = new ArrayList();
>> RbdSnapInfo snapInfo, snapInfos[];
>>
>> while (true) {
>> int r = rbd.rbd_snap_list(this.getPointer(), snaps, numSnaps);
>
> I think you need to allocate the memory for `snaps` yourself. Here is
> the RBD wrapper for Python which does that:
>
> self.snaps = (rbd_snap_info_t * num_snaps.value)()
> ret = self.librbd.rbd_snap_list(image.image, byref(self.snaps),
>byref(num_snaps))
>
> - Noah
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Re: Need some help with the RBD Java bindings
On Thu, Aug 15, 2013 at 8:51 AM, Wido den Hollander wrote:
>
> public List snapList() throws RbdException {
> IntByReference numSnaps = new IntByReference(16);
> PointerByReference snaps = new PointerByReference();
> List list = new ArrayList();
> RbdSnapInfo snapInfo, snapInfos[];
>
> while (true) {
> int r = rbd.rbd_snap_list(this.getPointer(), snaps, numSnaps);
I think you need to allocate the memory for `snaps` yourself. Here is
the RBD wrapper for Python which does that:
self.snaps = (rbd_snap_info_t * num_snaps.value)()
ret = self.librbd.rbd_snap_list(image.image, byref(self.snaps),
byref(num_snaps))
- Noah
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Need some help with the RBD Java bindings
Hi,
I'm having some issues with the Java bindings for librbd and I'm not
sure what the problem is here.
The problem is with listing snapshot of a RBD image. I test it in this
test case:
public void testCreateAndClone() {
try {
..
..
image.snapCreate(snapName);
image.snapProtect(snapName);
List snaps = image.snapList();
assertEquals("There should only be one snapshot", 1, snaps.size());
..
..
}
}
This test fails 95% of the time with my whole JVM crashing.
The code to blame is in RbdImage.java:
public List snapList() throws RbdException {
IntByReference numSnaps = new IntByReference(16);
PointerByReference snaps = new PointerByReference();
List list = new ArrayList();
RbdSnapInfo snapInfo, snapInfos[];
while (true) {
int r = rbd.rbd_snap_list(this.getPointer(), snaps, numSnaps);
if (r >= 0) {
numSnaps.setValue(r);
break;
} else {
throw new RbdException("Failed listing snapshots", r);
}
}
Pointer p = snaps.getValue(); crash
snapInfo = new RbdSnapInfo(p);
..
..
}
So it crashes when it wants to get the value of the snaps var.
I can't figure out why this is happening and why it isn't consistent.
I'm not a real JNA expert and I was hoping somebody around here would be
able to figure out what I'm doing wrong.
Any Java/JNA experts around who might have a clue?
The source of rados-java: https://github.com/wido/rados-java
--
Wido den Hollander
42on B.V.
Phone: +31 (0)20 700 9902
Skype: contact42on
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