RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out

Discussion:

Reingruber, Richard

2018-11-15 22:32:26 UTC

Hi,

could I please get reviews for the following small patch? It fixes a bug in the test
com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock when executed with
-vmoption:-Xcomp.

Deadlock:

Debuggee (SetLocalWhileThreadInNativeTarget):
- running with -Xcomp
- still in early start-up
- printed a lot on tty already, because -XX:+PrintCompilation -XX:+PrintInlining are given
- java thread waits for compiler thread to finish compile task
- compiler thread is blocked in write on tty. tty buffer is full, because debugger is not yet
reading debuggee's output

Debugger
- waiting until connection to debugger is established

The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In addition it excludes the test if
running with -Xcomp, because that mode does not add a lot of value, as the test actually only needs
dontinline_testMethod() to be compiled. Running with -Xcomp just wastes energy.

Webrev: http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8213902

The contribution needs to be sponsored as well, please.

Thanks, Richard.

JC Beyler

2018-11-16 04:13:47 UTC

Permalink

Hi Richard,

Is this not a test that's failing due to a real bug? Ie: if someone were to
really be running the program in this configuration (with printcompilation
and printinlining) and attaching a debugger, would they not reach the same
issue?

Should that not be fixed in some way instead? Or is this such an improbable
case that we just consider it ludicrous?

Thanks,
Jc

On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard <

Post by Reingruber, Richard
Hi,
could I please get reviews for the following small patch? It fixes a bug in the test
com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock when executed with
-vmoption:-Xcomp.
- running with -Xcomp
- still in early start-up
- printed a lot on tty already, because -XX:+PrintCompilation
-XX:+PrintInlining are given
- java thread waits for compiler thread to finish compile task
- compiler thread is blocked in write on tty. tty buffer is full,
because debugger is not yet
reading debuggee's output
Debugger
- waiting until connection to debugger is established
The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In addition
it excludes the test if
running with -Xcomp, because that mode does not add a lot of value, as the
test actually only needs
dontinline_testMethod() to be compiled. Running with -Xcomp just wastes energy.
Webrev: http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
The contribution needs to be sponsored as well, please.
Thanks, Richard.

--
Thanks,
Jc

David Holmes

2018-11-16 04:40:09 UTC

Permalink

Hi Jc,

If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone were
to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would they
not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the point
where it communicates back to the initial process (which would trigger
the initial process to start draining the pipe) then you effectively
deadlock.

So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.

For the case at hand fixing the test to not be so verbose is reasonable
in my opinion, though I'm not sure I'd remove Xcomp altogether as Xcomp
likes a range of programs to put it through its paces.

But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.

Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
Hi,
could I please get reviews for the following small patch? It fixes a
bug in the test
com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock
when executed with
-vmoption:-Xcomp.
- running with -Xcomp
- still in early start-up
- printed a lot on tty already, because -XX:+PrintCompilation
-XX:+PrintInlining are given
- java thread waits for compiler thread to finish compile task
- compiler thread is blocked in write on tty. tty buffer is full,
because debugger is not yet
reading debuggee's output
Debugger
- waiting until connection to debugger is established
The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
addition it excludes the test if
running with -Xcomp, because that mode does not add a lot of value,
as the test actually only needs
dontinline_testMethod() to be compiled. Running with -Xcomp just wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
The contribution needs to be sponsored as well, please.
Thanks, Richard.
--
Thanks,
Jc

Chris Plummer

2018-11-16 05:22:39 UTC

Permalink

See https://bugs.openjdk.java.net/browse/JDK-8173304 and also
https://bugs.openjdk.java.net/browse/JDK-4368399, which dates back to 2000.

Chris

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone
were to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would
they not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the
point where it communicates back to the initial process (which would
trigger the initial process to start draining the pipe) then you
effectively deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is
reasonable in my opinion, though I'm not sure I'd remove Xcomp
altogether as Xcomp likes a range of programs to put it through its
paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
    Hi,
    could I please get reviews for the following small patch? It fixes a
    bug in the test
    com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock
    when executed with
    -vmoption:-Xcomp.
     - running with -Xcomp
     - still in early start-up
     - printed a lot on tty already, because -XX:+PrintCompilation
    -XX:+PrintInlining are given
     - java thread waits for compiler thread to finish compile task
     - compiler thread is blocked in write on tty. tty buffer is full,
    because debugger is not yet
     reading debuggee's output
    Debugger
     - waiting until connection to debugger is established
    The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
    addition it excludes the test if
    running with -Xcomp, because that mode does not add a lot of value,
    as the test actually only needs
    dontinline_testMethod() to be compiled. Running with -Xcomp just
    wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
    Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
    The contribution needs to be sponsored as well, please.
    Thanks, Richard.
--
Thanks,
Jc

Reingruber, Richard

2018-11-16 15:37:45 UTC

Permalink

Hi Jc, David, Chris,

Post by David Holmes

Post by JC Beyler
Is this not a test that's failing due to a real bug?

I would not consider this a bug, but rather a limitation. I don't see a way to
work around it in the TestScaffold, though (looking at [1]).

So an enhancement would have to happen in the jdi implementation. To me it does
not seem worth the effort. I'd say the tracing is not necessary for regression
testing. In the case of a test error where all that output is required, I'd
start the debuggee in a shell and do the debugging manually.

Regarding -Xcomp: makes a lot of sense for tests that are indifferent about the
execution mode. The test at hand triggers compilation of the central test
method. It does not help that much, to compile everything else, too.

Anyway, here is another webrev without excluding -Xcomp:

http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.02/

I'd prefer the original webrev, because it's greener ;)

I would need a sponsor, too. Please take either one of the patches.

Thanks for reviewing,
Richard.

[1] Debugger stack

java.lang.Object.wait(long) line: not available [native method]
com.sun.tools.jdi.AbstractLauncher$Helper(java.lang.Object).wait() line: 328
com.sun.tools.jdi.AbstractLauncher$Helper.launchAndAccept() line: 197
com.sun.tools.jdi.SunCommandLineLauncher(com.sun.tools.jdi.AbstractLauncher).launch(java.lang.String[], java.lang.String, com.sun.jdi.connect.spi.TransportService$ListenKey, com.sun.jdi.connect.spi.TransportService) line: 140
com.sun.tools.jdi.SunCommandLineLauncher.launch(java.util.Map<java.lang.String,? extends com.sun.jdi.connect.Connector.Argument>) line: 229
VMConnection.launchTarget() line: 314
VMConnection.open() line: 149
SetLocalWhileThreadInNative(TestScaffold).connect(java.lang.String[]) line: 637
SetLocalWhileThreadInNative(TestScaffold).startUp(java.lang.String) line: 364
SetLocalWhileThreadInNative(TestScaffold).startTo(java.lang.String, java.lang.String, java.lang.String) line: 374
SetLocalWhileThreadInNative(TestScaffold).startToMain(java.lang.String) line: 369
SetLocalWhileThreadInNative.runTests() line: 132
SetLocalWhileThreadInNative(TestScaffold).startTests() line: 431
SetLocalWhileThreadInNative.main(java.lang.String[]) line: 120

-----Original Message-----
From: Chris Plummer <***@oracle.com>
Sent: Freitag, 16. November 2018 06:23
To: David Holmes <***@oracle.com>; JC Beyler <***@google.com>; Reingruber, Richard <***@sap.com>
Cc: serviceability-***@openjdk.java.net
Subject: Re: RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out

See https://bugs.openjdk.java.net/browse/JDK-8173304 and also
https://bugs.openjdk.java.net/browse/JDK-4368399, which dates back to 2000.

Chris

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone
were to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would
they not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the
point where it communicates back to the initial process (which would
trigger the initial process to start draining the pipe) then you
effectively deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is
reasonable in my opinion, though I'm not sure I'd remove Xcomp
altogether as Xcomp likes a range of programs to put it through its
paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
    Hi,
    could I please get reviews for the following small patch? It fixes a
    bug in the test
    com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock
    when executed with
    -vmoption:-Xcomp.
     - running with -Xcomp
     - still in early start-up
     - printed a lot on tty already, because -XX:+PrintCompilation
    -XX:+PrintInlining are given
     - java thread waits for compiler thread to finish compile task
     - compiler thread is blocked in write on tty. tty buffer is full,
    because debugger is not yet
     reading debuggee's output
    Debugger
     - waiting until connection to debugger is established
    The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
    addition it excludes the test if
    running with -Xcomp, because that mode does not add a lot of value,
    as the test actually only needs
    dontinline_testMethod() to be compiled. Running with -Xcomp just
    wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
    Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
    The contribution needs to be sponsored as well, please.
    Thanks, Richard.

David Holmes

2018-11-16 22:34:00 UTC

Permalink

Hi Richard,

I'll sponsor this over the weekend.

Thanks,
David

Post by Reingruber, Richard
Hi Jc, David, Chris,

Post by David Holmes

Post by JC Beyler
Is this not a test that's failing due to a real bug?

I would not consider this a bug, but rather a limitation. I don't see a way to
work around it in the TestScaffold, though (looking at [1]).
So an enhancement would have to happen in the jdi implementation. To me it does
not seem worth the effort. I'd say the tracing is not necessary for regression
testing. In the case of a test error where all that output is required, I'd
start the debuggee in a shell and do the debugging manually.
Regarding -Xcomp: makes a lot of sense for tests that are indifferent about the
execution mode. The test at hand triggers compilation of the central test
method. It does not help that much, to compile everything else, too.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.02/
I'd prefer the original webrev, because it's greener ;)
I would need a sponsor, too. Please take either one of the patches.
Thanks for reviewing,
Richard.
[1] Debugger stack
java.lang.Object.wait(long) line: not available [native method]
com.sun.tools.jdi.AbstractLauncher$Helper(java.lang.Object).wait() line: 328
com.sun.tools.jdi.AbstractLauncher$Helper.launchAndAccept() line: 197
com.sun.tools.jdi.SunCommandLineLauncher(com.sun.tools.jdi.AbstractLauncher).launch(java.lang.String[], java.lang.String, com.sun.jdi.connect.spi.TransportService$ListenKey, com.sun.jdi.connect.spi.TransportService) line: 140
com.sun.tools.jdi.SunCommandLineLauncher.launch(java.util.Map<java.lang.String,? extends com.sun.jdi.connect.Connector.Argument>) line: 229
VMConnection.launchTarget() line: 314
VMConnection.open() line: 149
SetLocalWhileThreadInNative(TestScaffold).connect(java.lang.String[]) line: 637
SetLocalWhileThreadInNative(TestScaffold).startUp(java.lang.String) line: 364
SetLocalWhileThreadInNative(TestScaffold).startTo(java.lang.String, java.lang.String, java.lang.String) line: 374
SetLocalWhileThreadInNative(TestScaffold).startToMain(java.lang.String) line: 369
SetLocalWhileThreadInNative.runTests() line: 132
SetLocalWhileThreadInNative(TestScaffold).startTests() line: 431
SetLocalWhileThreadInNative.main(java.lang.String[]) line: 120
-----Original Message-----
Sent: Freitag, 16. November 2018 06:23
Subject: Re: RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out
See https://bugs.openjdk.java.net/browse/JDK-8173304 and also
https://bugs.openjdk.java.net/browse/JDK-4368399, which dates back to 2000.
Chris

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone
were to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would
they not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the
point where it communicates back to the initial process (which would
trigger the initial process to start draining the pipe) then you
effectively deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is
reasonable in my opinion, though I'm not sure I'd remove Xcomp
altogether as Xcomp likes a range of programs to put it through its
paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
    Hi,
    could I please get reviews for the following small patch? It fixes a
    bug in the test
    com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock
    when executed with
    -vmoption:-Xcomp.
     - running with -Xcomp
     - still in early start-up
     - printed a lot on tty already, because -XX:+PrintCompilation
    -XX:+PrintInlining are given
     - java thread waits for compiler thread to finish compile task
     - compiler thread is blocked in write on tty. tty buffer is full,
    because debugger is not yet
     reading debuggee's output
    Debugger
     - waiting until connection to debugger is established
    The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
    addition it excludes the test if
    running with -Xcomp, because that mode does not add a lot of value,
    as the test actually only needs
    dontinline_testMethod() to be compiled. Running with -Xcomp just
    wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
    Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
    The contribution needs to be sponsored as well, please.
    Thanks, Richard.
--
Thanks,
Jc

David Holmes

2018-11-17 23:06:47 UTC

Permalink

Version 2 pushed.

Richard: I'm unclear about your Author status as you are somehow only
listed as a JDK 9 Author ? And I thought all existing Authors were
automatically added to the JDK project.

Cheers,
David

Post by JC Beyler
Hi Richard,
I'll sponsor this over the weekend.
Thanks,
David

Post by Reingruber, Richard
Hi Jc, David, Chris,
>> Is this not a test that's failing due to a real bug?
I would not consider this a bug, but rather a limitation. I don't see a way to
work around it in the TestScaffold, though (looking at [1]).
So an enhancement would have to happen in the jdi implementation. To me it does
not seem worth the effort. I'd say the tracing is not necessary for regression
testing. In the case of a test error where all that output is
required, I'd
start the debuggee in a shell and do the debugging manually.
Regarding -Xcomp: makes a lot of sense for tests that are indifferent about the
execution mode. The test at hand triggers compilation of the central test
method. It does not help that much, to compile everything else, too.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.02/
I'd prefer the original webrev, because it's greener ;)
I would need a sponsor, too. Please take either one of the patches.
Thanks for reviewing,
Richard.
[1] Debugger stack
java.lang.Object.wait(long) line: not available [native method]
com.sun.tools.jdi.AbstractLauncher$Helper(java.lang.Object).wait() line: 328
com.sun.tools.jdi.AbstractLauncher$Helper.launchAndAccept() line: 197
com.sun.tools.jdi.SunCommandLineLauncher(com.sun.tools.jdi.AbstractLauncher).launch(java.lang.String[],
java.lang.String, com.sun.jdi.connect.spi.TransportService$ListenKey,
com.sun.jdi.connect.spi.TransportService) line: 140
com.sun.tools.jdi.SunCommandLineLauncher.launch(java.util.Map<java.lang.String,?
extends com.sun.jdi.connect.Connector.Argument>) line: 229
VMConnection.launchTarget() line: 314
VMConnection.open() line: 149
SetLocalWhileThreadInNative(TestScaffold).connect(java.lang.String[]) line: 637
SetLocalWhileThreadInNative(TestScaffold).startUp(java.lang.String) line: 364
SetLocalWhileThreadInNative(TestScaffold).startTo(java.lang.String,
java.lang.String, java.lang.String) line: 374
SetLocalWhileThreadInNative(TestScaffold).startToMain(java.lang.String) line: 369
SetLocalWhileThreadInNative.runTests() line: 132
SetLocalWhileThreadInNative(TestScaffold).startTests() line: 431
SetLocalWhileThreadInNative.main(java.lang.String[]) line: 120
-----Original Message-----
Sent: Freitag, 16. November 2018 06:23
com/sun/jdi/SetLocalWhileThreadInNative.java times out
See https://bugs.openjdk.java.net/browse/JDK-8173304 and also
https://bugs.openjdk.java.net/browse/JDK-4368399, which dates back to 2000.
Chris

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone
were to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would
they not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the
point where it communicates back to the initial process (which would
trigger the initial process to start draining the pipe) then you
effectively deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is
reasonable in my opinion, though I'm not sure I'd remove Xcomp
altogether as Xcomp likes a range of programs to put it through its
paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
     Hi,
     could I please get reviews for the following small patch? It
fixes a
     bug in the test
     com/sun/jdi/SetLocalWhileThreadInNative.java that causes a
deadlock
     when executed with
     -vmoption:-Xcomp.
      - running with -Xcomp
      - still in early start-up
      - printed a lot on tty already, because -XX:+PrintCompilation
     -XX:+PrintInlining are given
      - java thread waits for compiler thread to finish compile task
      - compiler thread is blocked in write on tty. tty buffer is
full,
     because debugger is not yet
      reading debuggee's output
     Debugger
      - waiting until connection to debugger is established
     The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
     addition it excludes the test if
     running with -Xcomp, because that mode does not add a lot of
value,
     as the test actually only needs
     dontinline_testMethod() to be compiled. Running with -Xcomp just
     wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
     Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
     The contribution needs to be sponsored as well, please.
     Thanks, Richard.
--
Thanks,
Jc

Reingruber, Richard

2018-11-18 20:57:21 UTC

Permalink

Thank you David.

Regarding my status: you're right. I noticed it, too, but wasn't sure what to do. Can you tell me?

Thanks again, Richard.

-----Original Message-----
From: David Holmes <***@oracle.com>
Sent: Sonntag, 18. November 2018 00:07
To: Reingruber, Richard <***@sap.com>; JC Beyler <***@google.com>
Cc: serviceability-***@openjdk.java.net
Subject: Re: RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out

Version 2 pushed.

Richard: I'm unclear about your Author status as you are somehow only
listed as a JDK 9 Author ? And I thought all existing Authors were
automatically added to the JDK project.

Cheers,
David

Post by JC Beyler
Hi Richard,
I'll sponsor this over the weekend.
Thanks,
David

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone
were to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would
they not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the
point where it communicates back to the initial process (which would
trigger the initial process to start draining the pipe) then you
effectively deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is
reasonable in my opinion, though I'm not sure I'd remove Xcomp
altogether as Xcomp likes a range of programs to put it through its
paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
     Hi,
     could I please get reviews for the following small patch? It
fixes a
     bug in the test
     com/sun/jdi/SetLocalWhileThreadInNative.java that causes a
deadlock
     when executed with
     -vmoption:-Xcomp.
      - running with -Xcomp
      - still in early start-up
      - printed a lot on tty already, because -XX:+PrintCompilation
     -XX:+PrintInlining are given
      - java thread waits for compiler thread to finish compile task
      - compiler thread is blocked in write on tty. tty buffer is
full,
     because debugger is not yet
      reading debuggee's output
     Debugger
      - waiting until connection to debugger is established
     The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
     addition it excludes the test if
     running with -Xcomp, because that mode does not add a lot of
value,
     as the test actually only needs
     dontinline_testMethod() to be compiled. Running with -Xcomp just
     wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
     Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
     The contribution needs to be sponsored as well, please.
     Thanks, Richard.
--

David Holmes

2018-11-18 21:58:04 UTC

Permalink

Hi Richard,

Post by Reingruber, Richard
Thank you David.
Regarding my status: you're right. I noticed it, too, but wasn't sure what to do. Can you tell me?

You'll need to contact the JDK Project lead (Mark Reinhold) , as you
would have done when you got your JDK 9 Author role.

Cheers,
David

Post by Reingruber, Richard
Thanks again, Richard.
-----Original Message-----
Sent: Sonntag, 18. November 2018 00:07
Subject: Re: RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out
Version 2 pushed.
Richard: I'm unclear about your Author status as you are somehow only
listed as a JDK 9 Author ? And I thought all existing Authors were
automatically added to the JDK project.
Cheers,
David

Post by JC Beyler
Hi Richard,
I'll sponsor this over the weekend.
Thanks,
David

Post by Reingruber, Richard
Hi Jc, David, Chris,
>> Is this not a test that's failing due to a real bug?
I would not consider this a bug, but rather a limitation. I don't see a way to
work around it in the TestScaffold, though (looking at [1]).
So an enhancement would have to happen in the jdi implementation. To me it does
not seem worth the effort. I'd say the tracing is not necessary for regression
testing. In the case of a test error where all that output is required, I'd
start the debuggee in a shell and do the debugging manually.
Regarding -Xcomp: makes a lot of sense for tests that are indifferent about the
execution mode. The test at hand triggers compilation of the central test
method. It does not help that much, to compile everything else, too.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.02/
I'd prefer the original webrev, because it's greener ;)
I would need a sponsor, too. Please take either one of the patches.
Thanks for reviewing,
Richard.
[1] Debugger stack
java.lang.Object.wait(long) line: not available [native method]
com.sun.tools.jdi.AbstractLauncher$Helper(java.lang.Object).wait() line: 328
com.sun.tools.jdi.AbstractLauncher$Helper.launchAndAccept() line: 197
com.sun.tools.jdi.SunCommandLineLauncher(com.sun.tools.jdi.AbstractLauncher).launch(java.lang.String[],
java.lang.String, com.sun.jdi.connect.spi.TransportService$ListenKey,
com.sun.jdi.connect.spi.TransportService) line: 140
com.sun.tools.jdi.SunCommandLineLauncher.launch(java.util.Map<java.lang.String,?
extends com.sun.jdi.connect.Connector.Argument>) line: 229
VMConnection.launchTarget() line: 314
VMConnection.open() line: 149
SetLocalWhileThreadInNative(TestScaffold).connect(java.lang.String[]) line: 637
SetLocalWhileThreadInNative(TestScaffold).startUp(java.lang.String) line: 364
SetLocalWhileThreadInNative(TestScaffold).startTo(java.lang.String,
java.lang.String, java.lang.String) line: 374
SetLocalWhileThreadInNative(TestScaffold).startToMain(java.lang.String) line: 369
SetLocalWhileThreadInNative.runTests() line: 132
SetLocalWhileThreadInNative(TestScaffold).startTests() line: 431
SetLocalWhileThreadInNative.main(java.lang.String[]) line: 120
-----Original Message-----
Sent: Freitag, 16. November 2018 06:23
com/sun/jdi/SetLocalWhileThreadInNative.java times out
See https://bugs.openjdk.java.net/browse/JDK-8173304 and also
https://bugs.openjdk.java.net/browse/JDK-4368399, which dates back to 2000.
Chris

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

Post by JC Beyler
Hi Richard,
Is this not a test that's failing due to a real bug? Ie: if someone
were to really be running the program in this configuration (with
printcompilation and printinlining) and attaching a debugger, would
they not reach the same issue?

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the
point where it communicates back to the initial process (which would
trigger the initial process to start draining the pipe) then you
effectively deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is
reasonable in my opinion, though I'm not sure I'd remove Xcomp
altogether as Xcomp likes a range of programs to put it through its
paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

Post by JC Beyler
Should that not be fixed in some way instead? Or is this such an
improbable case that we just consider it ludicrous?
Thanks,
Jc
On Thu, Nov 15, 2018 at 2:32 PM Reingruber, Richard
     Hi,
     could I please get reviews for the following small patch? It
fixes a
     bug in the test
     com/sun/jdi/SetLocalWhileThreadInNative.java that causes a
deadlock
     when executed with
     -vmoption:-Xcomp.
      - running with -Xcomp
      - still in early start-up
      - printed a lot on tty already, because -XX:+PrintCompilation
     -XX:+PrintInlining are given
      - java thread waits for compiler thread to finish compile task
      - compiler thread is blocked in write on tty. tty buffer is
full,
     because debugger is not yet
      reading debuggee's output
     Debugger
      - waiting until connection to debugger is established
     The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In
     addition it excludes the test if
     running with -Xcomp, because that mode does not add a lot of
value,
     as the test actually only needs
     dontinline_testMethod() to be compiled. Running with -Xcomp just
     wastes energy.
http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
     Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
     The contribution needs to be sponsored as well, please.
     Thanks, Richard.
--
Thanks,
Jc

JC Beyler

2018-11-16 16:04:16 UTC

Permalink

Hi David,

Thanks for the explanation :) That makes sense to me,
Jc

Post by David Holmes
Hi Jc,
If I may put in my 2c ...

This is just a limitation of connecting process streams via finite
pipes. If the pipe can fill before the target process reaches the point
where it communicates back to the initial process (which would trigger
the initial process to start draining the pipe) then you effectively
deadlock.
So you either structure the tests so that they work correctly with the
finite pipes provided by the test scaffold, or you modify the test
scaffold to either provide a bigger pipe or else rework it to ensure
pipes can't fill and cause indefinite blocking.
For the case at hand fixing the test to not be so verbose is reasonable
in my opinion, though I'm not sure I'd remove Xcomp altogether as Xcomp
likes a range of programs to put it through its paces.
But it wouldn't be unreasonable to file a RFE to make the TestScaffold
handle this better.
Cheers,
David

--
Thanks,
Jc

David Holmes

2018-11-16 04:43:17 UTC

Permalink

Hi Richard,

I think your test is misusing @driver. If you want to pass -XX args you
should be using "@run main/othervm"

Otherwise turning off the Print* flags seems reasonable, but removing
Xcomp as well seems unnecessary.

Cheers,
David

Post by Reingruber, Richard
Hi,
could I please get reviews for the following small patch? It fixes a bug in the test
com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock when executed with
-vmoption:-Xcomp.
- running with -Xcomp
- still in early start-up
- printed a lot on tty already, because -XX:+PrintCompilation -XX:+PrintInlining are given
- java thread waits for compiler thread to finish compile task
- compiler thread is blocked in write on tty. tty buffer is full, because debugger is not yet
reading debuggee's output
Debugger
- waiting until connection to debugger is established
The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In addition it excludes the test if
running with -Xcomp, because that mode does not add a lot of value, as the test actually only needs
dontinline_testMethod() to be compiled. Running with -Xcomp just wastes energy.
Webrev: http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
The contribution needs to be sponsored as well, please.
Thanks, Richard.

Reingruber, Richard

2018-11-16 15:32:33 UTC

Permalink

Hi David,

I would like to pass -XX args mainly to the debuggee which is launched by
SetLocalWhileThreadInNative. There's no need to run SetLocalWhileThreadInNative
in another vm.

Do you think this is a misuse?

Thanks for looking at the patch,
Richard.

-----Original Message-----
From: David Holmes <***@oracle.com>
Sent: Freitag, 16. November 2018 05:43
To: Reingruber, Richard <***@sap.com>; serviceability-***@openjdk.java.net
Subject: Re: RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out

Hi Richard,

I think your test is misusing @driver. If you want to pass -XX args you
should be using "@run main/othervm"

Otherwise turning off the Print* flags seems reasonable, but removing
Xcomp as well seems unnecessary.

Cheers,
David

Post by Reingruber, Richard
Hi,
could I please get reviews for the following small patch? It fixes a bug in the test
com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock when executed with
-vmoption:-Xcomp.
- running with -Xcomp
- still in early start-up
- printed a lot on tty already, because -XX:+PrintCompilation -XX:+PrintInlining are given
- java thread waits for compiler thread to finish compile task
- compiler thread is blocked in write on tty. tty buffer is full, because debugger is not yet
reading debuggee's output
Debugger
- waiting until connection to debugger is established
The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In addition it excludes the test if
running with -Xcomp, because that mode does not add a lot of value, as the test actually only needs
dontinline_testMethod() to be compiled. Running with -Xcomp just wastes energy.
Webrev: http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
The contribution needs to be

David Holmes

2018-11-16 22:27:42 UTC

Permalink

Post by Reingruber, Richard
Hi David,
I would like to pass -XX args mainly to the debuggee which is launched by
SetLocalWhileThreadInNative. There's no need to run SetLocalWhileThreadInNative
in another vm.

Sorry Richard I misread the driver line and didn't notice that these are
actually "application" args that the test then uses for its internal
launch of the debuggee.

Thanks,
David

Post by Reingruber, Richard
Do you think this is a misuse?
Thanks for looking at the patch,
Richard.
-----Original Message-----
Sent: Freitag, 16. November 2018 05:43
Subject: Re: RFR(XXS): 8213902: com/sun/jdi/SetLocalWhileThreadInNative.java times out
Hi Richard,
Otherwise turning off the Print* flags seems reasonable, but removing
Xcomp as well seems unnecessary.
Cheers,
David

Post by Reingruber, Richard
Hi,
could I please get reviews for the following small patch? It fixes a bug in the test
com/sun/jdi/SetLocalWhileThreadInNative.java that causes a deadlock when executed with
-vmoption:-Xcomp.
- running with -Xcomp
- still in early start-up
- printed a lot on tty already, because -XX:+PrintCompilation -XX:+PrintInlining are given
- java thread waits for compiler thread to finish compile task
- compiler thread is blocked in write on tty. tty buffer is full, because debugger is not yet
reading debuggee's output
Debugger
- waiting until connection to debugger is established
The fix is to remove -XX:+PrintCompilation -XX:+PrintInlining. In addition it excludes the test if
running with -Xcomp, because that mode does not add a lot of value, as the test actually only needs
dontinline_testMethod() to be compiled. Running with -Xcomp just wastes energy.
Webrev: http://cr.openjdk.java.net/~rrich/webrevs/2018/8213902/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8213902
The contribution needs to be sponsored as well, please.
Thanks, Richard.