Hi Chris,
This looks good to me.
Just one minor comment:
140 long estimatedTime = System.currentTimeMillis() - startTime;
Did you want to name this local "elapsedTime", not
"estimatedTime"? :)
Thanks,
Serguei
On 9/19/19 22:31, Chris Plummer wrote:
Here's
a new webrev:
http://cr.openjdk.java.net/~cjplummer/8228625/webrev.01/
I decided to add a 2 second delay to make sure the test always
passes and avoids the issues in JDK-8230872. After some internal
discussion there seems to be some consensus that SA is probably
not very stable when attaching to an active process, and I'd
rather not have those issues disrupting this test. I filed a CR to
write a new test without the 2 second delay so we can still
reproduce these issues. See:
https://bugs.openjdk.java.net/browse/JDK-8231288
Besides now using ProcessTools.startProcess() with a line
predicate instead of Runtime.exec(), I also did a bit of cleaning
up of variable names and added a few more diagnostic printlns.
thanks,
Chris
On 9/19/19 2:40 PM, Chris Plummer wrote:
One thing I didn't mention before is that
using "jshell> " as the line predicate does not work because
jshell does not produce a \n after generating this prompt, thus
it's not actually a line and no attempt will be made to match
it, so eventually it times out. I fixed this by using a snippet
from one of the previous 2 lines"
Welcome to JShell -- Version 14-internal
For an introduction type: /help intro
I now search for "Welcome to JShell", which is working.
I think this is related to additional issues I am having with
this fix. I used to see JDK-8230872 happen about 1% of the time
after the original fix I had for this CR (8228625). However, now
it fails about 9% of the time. It seems that this new fix is
making it more likely that jshell will be in a state that will
uncover jmap bugs. If I add another 10 second delay to the test,
all the jmap problems go away.
This started to get me thinking that maybe "jmap --pid" is just
not reliable. We do have a few other tests for this, but I
believe they all wait until the target process has all threads
blocked before issuing the jmap command. This might be why they
don't see problems. In the case of this test, since I don't
fully wait for the jshell> prompt, there is still probably
some jshell activity when jmap attaches. Waiting an extra 10
seconds gets us past this activity, and likely jshell is blocked
waiting for input. In fact even just waiting 1 additional second
seems to be long enough.
Chris
On 9/18/19 9:44 PM, Chris Plummer wrote:
I got this to work, although it
increased the test time from about 30s to over 3m. I looked
into it a bit and it appears to be due to the size of the
generate hprof file. It used to be about 300k, but now is
nearly 7mb. I guess that's because jshell has been run for
longer and probably allocated more data.
I need to do some more testing and a bit of cleanup. I'll get
another review out tomorrow.
Chris
Suddenly the test time is taking
On 9/18/19 5:43 PM, Chris Plummer wrote:
Ok. It was a bit unclear to me why the
author went with Runtime.exec() in the first place. I'll try
ProcessTools. That will probably however, hide 8230872. I
might need to write another test for it.
Chris
On 9/18/19 4:29 PM, Alex Menkov wrote:
You can use jdk.test.lib classes to
simplify the things.
Something like
ProcessBuilder pb = new
ProcessBuilder(JDKToolFinder.getTestJDKTool("jshell"));
Process p = ProcessTools.startProcess("JShell", pb,
s -> { // warm-up predicate
return s.contains(">jshell");
});
--alex
On 09/18/2019 15:44, Chris Plummer wrote:
Is there an easy way of doing
this? Currently the jshell process is just spawned using
Runtime.exec().
Chris
On 9/18/19 3:01 PM, Alex Menkov wrote:
Hi Chris,
Did you think about waiting for jshell prompt
("jshell>") before run "jhsdb jmap" command instead
of delay or re-tries?
--alex
On 09/18/2019 14:11, Chris Plummer wrote:
Hello,
Please review the following changes:
http://cr.openjdk.java.net/~cjplummer/8228625/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8228625
There are actually numerous ways that
JShellHeapDumpTest.java fails. One is a test bug,
being addressed here, and the rest all seem to be SA
bugs. Those are now being covered by JDK-8230872.
All the issues seem to stem from the fact that the
test spawns a jshell process, and then immediately
does a "jhsdb jmap" on the process before jshell has
fully started up.
The test bug happens when the jmap succeeds, but
jshell has not yet entered the main java thread.
Thus the search for "JShellToolProvider" in the
output fails. It expects "JShellToolProvider" to be
in the output because it is part of a method name in
the main thread, and the test dump all the thread
stacks contained in the jmap generated hprof file.
When the test fails in this way, you can see the
stack dump in the output, but the main thread is
missing.
There's a couple of ways to fix this. One is to just
add a delay (10s seems to be more than enough), and
the other is to retry the "jhsdb jmap" command until
the stack contains the JShellToolProvider symbol. I
chose the later because doing a 10s delay masks the
SA issues that are now covered by JDK-8230872. In a
way the 10s delay is a better fix, because it makes
this test pass every time, but I did not like that
it also hid real SA problems in JDK-8230872. My plan
for now is to do this retry fix, and then if there
are too many failures due to JDK-8230872, then also
add a 10s delay, with the intention of removing it
once JDK-8230872 if fixed. From what I can see,
JDK-8230872 failures happen on about 1% of the runs.
I made a few of other changes. One was to no longer
redirect stderr from the jmap process as was done
from the following:
processBuilder.redirectError(ProcessBuilder.Redirect.INHERIT);
This causes the output not to appear in the
OutputAnalyzer output, resulting in the following
not working:
output.shouldNotContain("null");
Also I added code to dump the output of the jshell
process so you can see if the jshell prompt was ever
generated.
thanks,
Chris
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