cvs commit: src/sys/kern uipc_syscalls.c

[Robert Watson]

On Tue, 22 May 2007, Warner Losh wrote:

>> On Mon, 21 May 2007, Alfred Perlstein wrote:
>>
>>> Is this the same bug that used to be in sendfile but got corrected some 
>>> years back?
>>
>> Dunno, but it sounds like we really need a comprehensive set of edge-case 
>> tests for sendfile.
>
> There are those that advocate writing a test case that fails, then fixing 
> the code until the test case succeeds, then committing the test case to the 
> test-bed at the same time the code is committed to the tree.  With the 
> test-case gating the code.
>
> This works well for some thing, but we can't do it universally since some 
> test-cases would be only for 'rogue' hardware, which can't be automatically 
> tested.

In this case, the problem is that we already have a piece of complex subsystem 
code without tests, so we bump into both regressions and new bugs with 
moderate frequency, and need to write basic functional tests.

An interesting variable in test cases for sendfile, btw, is to use UNIX domain 
sockets as a transport, not just TCP

Robert N M Watson
Computer Laboratory
University of Cambridge