This reverts commit 8ea006ee.

does not seem to make a difference, trying to narrow down using other
means (different platforms)

V1L_Close() is now in charge of returning a specific enum sess_close
instead of an error flag where SC_NULL implies that everything went
well.

This otherwise maintains the status quo regarding prior handling of
HTTP/1 write errors. The calling code falls back to what it used to
default to when an error occurred somewhere else.

Under load, client c4 from g00005.vtc may fail with a 200 response
instead of the expected 206 partial response.

There is a window during which we might still see a boc, but because
c4 sets beresp.do_stream to false, the fetch has to be over. To close
this race we can instead reference the boc as suggested in #2904 and
keep track of the boc state.

Closes #3178

Contrary to previous attempts this one takes a different route that
is much more reliable and faster.

First, it sets things up so that we can predicatbly lock varnish when
it's trying to send the first (and only) part of the body. Instead of
assuming a delay that is sometimes not enough under load, we wait for
the timeout to show up in the log.

We can't put the barrier in l1 or l2 because logexpect spec evaluation
is eager, in order to cope with the VSL API.

Because we bypass the cache, we can afford letting c1 bail out before
completing the transaction, which is necessary because otherwise the
second c1 run would take forever on FreeBSD that takes our request to
limit the send buffer to 128 octets very seriously (on Linux we get
around 4k).

Because we use barriers, the send and receive buffers were bumped to
256 to ensure c1 doesn't fail (on FreeBSD) before it reaches barrier
statements.

This reverts commit df9f3489.

It succeeded in terms of determinism but there is another underlying bug
to fix so it will be submitted again via #3178 instead.

The fetch may be interrupted before s1 has time to buffer the complete
response.

This test has been relying on SLT_Debug records from day one and now
that we have SLT_Notice we could perpetuate this information and at
the same time grant ourselves the freedom to explain each case and
which parameters may be used to try to improve the situation.

I'm no longer able to time it out under load.

There was a race with the reuse of s1 and server -dispatch was the
simplest way to also circumvent the race where varnish could retry
before s1 would reach the next accept action.

While at it, add coverage for the 503 case.

Apparently this is missing in sunos+gcc 4.7.
While here tight things up a bit.

The previous tweak paid off, the problem is not an unexpected ReqAcct
when this test fails, but a lack of logs during the check.

The test cases disabling the accept_filter parameter are those involving
GET requests with a body that are meant to be cached, and one test case
covering OOB data. The rest uses the POST method since the httpready
filter will only let syntactically correct GET or HEAD methods pass to
the application.

Apparently FreeBSD's httpready filter considers that a GET request with
a body is syntactically incorrect although this is not specifically said
in the manual. The HTTP specification doesn't forbid such requests and
they are hard to justify considering the semantics of GET and HEAD, but
there are products in the wild relying on that.

On the other hand GET\r\n\r\n isn't considered malformed, see r01881.vtc.

We don't need the dataready filter on FreeBSD for listen addresses that
expect a PROXY protocol header, the httpready filter will effectively
work like that if the request doesn't look like a GET or a HEAD.

Trying to understand why I was seeing setsockopt fail on FreeBSD VTEST
boxes and why it failed with an undocumented ENOENT I finally realized
that I needed to kldload accf_http beforehand.

The ENOENT errno was probably a result of accept_filter code not finding
a kernel module for "httpready".

I couldn't reproduce the failure reported by VTEST but hopefully this
will shed some light next time it happens.

Better diff with the --word-diff option.

The change in u00011.vtc is the result of having two commands starting
with "pi", breaking auto-completion. Fortunately "pin\t" still does the
trick.

It was a bit racy in the sense that the logs for c2 could be committed
before the c1 logs. I hardened the expectations a bit in the process.

This adds the errno value to error logs for TCP fast open and accept
filters. For FreeBSD errno is cleared prior to calling setsockopt with
the hope that it will help understand if it's actually failing with an
undocumented ENOENT.

Speaking of documentation, the return value is either 0 or -1 for so
there's no point in logging that.

Once all instances of a given test are started all of the remaining
tests would free the test data structure, we needed another counter
to keep track of ongoing tests so that only the last one to finish
would do the single free.