[Spice-devel] [PATCH 2/2] vdagent: add max-clipboard message

[Uri Lublin]

On 11/08/2013 01:11 AM, Marc-André Lureau wrote:
> On Thu, Nov 7, 2013 at 11:58 PM, Uri Lublin <uril at redhat.com> wrote:
>> On 11/08/2013 12:37 AM, Marc-André Lureau wrote:
>>> On Thu, Nov 7, 2013 at 11:17 PM, Uri Lublin <uril at redhat.com> wrote:
>>>> On 11/06/2013 10:07 PM, Marc-André Lureau wrote:
>>>>> Add an optional message sent by the client to ask the agent not to send
>>>>> clipboard data bigger than a certain size, in bytes.  The message can be
>>>>> sent if the agent supports the capability MAX_CLIPBOARD, at any time.
>>>>>
>>>>> The agent is free to ignore or forget the value after a restart or a
>>>>> disconnection, but a bigger message might be discarded when received on
>>>>> client side, resulting in bandwidth waste.
>>>>
>>>> Hi Marc-Andre,
>>>>
>>>> Maybe better if they negotiate that size -- each report its supported max
>>>> and
>>>> the min max is picked.
>>> I don't think that make so much sense.
>>>
>>> If the client crash for OOM reason (which it shouldn't afaik, it is
>>> quite OOM-safe), it should be restarted automatically anyway.
>>>
>>> Furthermore, I think it's better if the client has full control over
>>> the setting, and not be limited by guest configuration which he could
>>> change.
>>>
>>> If really this is necessary for some obscure reason that I don't
>>> forsee, I'd  see that as a future protocol capability.
>>
>> I just thought that if it can crash the client, it's possible it can crash
>> the agent too.
>> Specifically I'm thinking of a Linux client and Windows agent.
>>
> Yes, it could eventually crash at any end point if they are not oom.
> That's the point of this message, to set a limit globally. Imho,
> further negotiation just complicates things for no clear benefit. Any
> the whole thing is not even guaranteed at any side, it's almost
> impossible to deal with OOM! it's just a little hint for setting. The
> client can say "I know I am never going to use a clipboard of 100mb,
> so just don't try". It's not actually about being OOM safe, it's more
> of a preference which has a nice side effect of avoiding crash in some
> cases.

OK, let's add this message and if needed we can add negotiation later.