RFR[ 9u-dev] JDK-8138745: Implement ExitOnOutOfMemory and CrashOnOutOfMemory in HotSpot

[David Holmes]

Sorry forgot the tests ....

test/runtime/ErrorHandling/TestExitOnOutOfMemoryError.java

This test is checking that new Object[Integer.MAX_VALUE]; caused the 
"Requested array size exceeds VM limit" failure _but_ it doesn't 
actually do anything to verify that the VM terminated because of the 
ExitOnOutOfMemory flag. I suggest:

a) augment the termination message in the VM as I suggested earlier so 
that you can be sure you hit the termination code
b) check for a zero/non-zero return code as appropriate
c) Add: throw new Error("OOME was not triggered"); after line 41.
d) Put a try/catch(OOME) around the allocation and throw an Error if you 
get to the catch block

That way we will get a test failure when Arrays 2.0 allows such massive 
arrays to be created :)

Similar considerations for TestCrashOnOutOfMemoryError.java, but you 
also need to disable core dump generation.

David
-----

On 26/11/2015 3:43 PM, David Holmes wrote:
> Hi,
>
> On 25/11/2015 10:40 PM, cheleswer sahu wrote:
>> Hi,
>>
>> Please review the code changes for
>> "https://bugs.openjdk.java.net/browse/JDK-8138745".
>> Web review link:
>> <http://cr.openjdk.java.net/%7Ekevinw/8138745/webrev.00/>http://cr.openjdk.java.net/~kevinw/8138745/webrev.00/
>>
>>
>> Enhancement Brief:
>> ExitOnOutOfMemoryError: When user enable this option, the JVM exits on
>> the first occurrence of an out-of-memory error. It can be used if user
>> prefer restarting an instance of the JVM rather than handling out of
>> memory errors.
>>
>> CrashOnOutOfMemoryError: If this option is enabled, when an
>> out-of-memory error occurs, the JVM crashes and produces text and binary
>> crash files.
>
> The term "crash" is not very appropriate - crashes are bad things. Abort
> may have been a better choice.
>
>> For more details please refer http://ccc.us.oracle.com/8138745
>
> This is not accessible outside of Oracle.
>
> A few minor comments:
>
> src/share/vm/runtime/globals.hpp
>
> +           "JVM crashes and produces text and binary crash files")
>
> Terminology should be consistent with other options that control core
> dump. Should also say "on first occurrence of an out-of-memory error".
>
> src/share/vm/utilities/debug.cpp:
>
>   308     if (CrashOnOutOfMemoryError) {
>   309       tty->print_cr("java.lang.OutOfMemoryError: %s", message);
>   310       fatal("OutOfMemory encountered: %s", message);
>   311     }
>
> don't really need the tty->print when using the fatal. Though you may
> want to use the j.l.OOME form of the message for consistency. Might also
> be useful for both Crash and Exit to include in the logged messages the
> fact that these flags were involved - something like:
>
> "Terminating due to java.lang.OutOfMemoryError: %s"
> "Aborting due to java.lang.OutOfMemoryError: %s"
>
> Thanks,
> David
> -----
>
>>
>> Regards,
>> Cheleswer
>>