For no obvious reason, isolationtester has always insisted that
session and step names be written with double quotes. This is
fairly tedious and does little for test readability, especially
since the names that people actually choose almost always look
like normal identifiers. Hence, let's tweak the lexer to allow
SQL-like identifiers not only double-quoted strings.
(They're SQL-like, not exactly SQL, because I didn't add any
case-folding logic. Also there's no provision for U&"..." names,
not that anyone's likely to care.)
There is one incompatibility introduced by this change: if you write
"foo""bar" with no space, that used to be taken as two identifiers,
but now it's just one identifier with an embedded quote mark.
I converted all the src/test/isolation/ specfiles to remove
unnecessary double quotes, but stopped there because my
eyes were glazing over already.
Like 741d7f104, back-patch to all supported branches, so that this
isn't a stumbling block for back-patching isolation test changes.
Discussion: https://postgr.es/m/759113.1623861959@sss.pgh.pa.us
If LISTEN is the only action in a serializable-mode transaction,
and the session was not previously listening, and the notify queue
is not empty, predicate.c reported an assertion failure. That
happened because we'd acquire the transaction's initial snapshot
during PreCommit_Notify, which was called *after* predicate.c
expects any such snapshot to have been established.
To fix, just swap the order of the PreCommit_Notify and
PreCommit_CheckForSerializationFailure calls during CommitTransaction.
This will imply holding the notify-insertion lock slightly longer,
but the difference could only be meaningful in serializable mode,
which is an expensive option anyway.
It appears that this is just an assertion failure, with no
consequences in non-assert builds. A snapshot used only to scan
the notify queue could not have been involved in any serialization
conflicts, so there would be nothing for
PreCommit_CheckForSerializationFailure to do except assign it a
prepareSeqNo and set the SXACT_FLAG_PREPARED flag. And given no
conflicts, neither of those omissions affect the behavior of
ReleasePredicateLocks. This admittedly once-over-lightly analysis
is backed up by the lack of field reports of trouble.
Per report from Mark Dilger. The bug is old, so back-patch to all
supported branches; but the new test case only goes back to 9.6,
for lack of adequate isolationtester infrastructure before that.
Discussion: https://postgr.es/m/3ac7f397-4d5f-be8e-f354-440020675694@gmail.com
Discussion: https://postgr.es/m/13881.1574557302@sss.pgh.pa.us
We had no actual end-to-end test of NOTIFY message delivery. In the
core async.sql regression test, testing this is problematic because psql
traditionally prints the PID of the sending backend, making the output
unstable. We also have an isolation test script, but it likewise
failed to prove that delivery worked, because isolationtester.c had
no provisions for detecting/reporting NOTIFY messages.
Hence, add such provisions to isolationtester.c, and extend
async-notify.spec to include direct tests of basic NOTIFY functionality.
I also added tests showing that NOTIFY de-duplicates messages normally,
but not across subtransaction boundaries. (That's the historical
behavior since we introduced subtransactions, though perhaps we ought
to change it.)
Patch by me, with suggestions/review by Andres Freund.
Discussion: https://postgr.es/m/31304.1564246011@sss.pgh.pa.us
I noticed that the async-notify test results in log messages like these:
LOG: could not send data to client: Broken pipe
FATAL: connection to client lost
This is because it unceremoniously disconnects a client session that is
about to have some NOTIFY messages delivered to it. Such log messages
during a regression test might well cause people to go looking for a
problem that doesn't really exist (it did cause me to waste some time that
way). We can shut it up by adding an UNLISTEN command to session teardown.
Patch HEAD only; this doesn't seem significant enough to back-patch.
This tells you what fraction of NOTIFY's queue is currently filled.
Brendan Jurd, reviewed by Merlin Moncure and Gurjeet Singh. A few
further tweaks by me.
Tom Lane
Robert Haas