Re: Full socket send buffer prevents cancel, timeout

Tom Lane wrote:
>"Stephen R. van den Berg" <srb(at)cuci(dot)nl> writes:
>> What about simply closing the filedescriptor upon discovering a
>> non-empty sendbuffer upon timeout/querycancel?

>So in other words, convert any network glitch, no matter how small,
>into an instant fatal error?

The fact that a timeout or querycancel has taken place, indicates that
this does *not* act on just any network glitch.
The preferred exact logic would look something like:

a. Take note of the time the last write returned as Tlastwritten.
b. Whenever a timeout occurs, or a querycancel is being requested:
c. Check if the sendbuffer is empty.
d. If the sendbuffer is non-empty *and* Tlastwritten is longer ago
than some Tkill (say 128 seconds), then close the filedescriptor.

In all other cases, just hang on tight.
--
Sincerely,
Stephen R. van den Berg.

Teamwork is essential -- it allows you to blame someone else.