Re: pg_waldump stucks with options --follow or -f and --stats or -z

On Sat, Nov 20, 2021 at 11:46:35AM +0530, Bharath Rupireddy wrote:
> Thanks. Here's the v3 patch, a much simpler one. Please review it.

+   pqsignal(SIGINT, SignalHandlerForTermination);
+   pqsignal(SIGTERM, SignalHandlerForTermination);
+   pqsignal(SIGQUIT, SignalHandlerForTermination);
FWIW, I think that we should do this stuff only on SIGINT.  I would
imagine that this behavior becomes handy mainly when one wishes to
Ctrl+C the terminal running pg_waldump but still get some
information.

     XLogDumpCountRecord(&config, &stats, xlogreader_state);
+    stats.endptr = xlogreader_state->currRecPtr;
Isn't what you are looking for here EndRecPtr rather than currRecPtr,
to track the end of the last record read?

+    When <option>--follow</option> is used with <option>--stats</option> and
+    the <application>pg_waldump</application> is terminated or interrupted
+    with signal <systemitem>SIGINT</systemitem> or <systemitem>SIGTERM</systemitem>
+    or <systemitem>SIGQUIT</systemitem>, the summary statistics computed
+    as of the termination will be displayed.
This description is not completely correct, as the set of stats would
show up only by using --stats, in non-quiet mode.  Rather than
describing this behavior at the end of the docs, I think that it would
be better to add a new paragraph in the description of --stats.
--
Michael