RFR (L): 8024545: make develop and notproduct flag values available in product builds

[Coleen Phillmore]

On 9/11/2013 12:29 PM, Christian Thalinger wrote:
> On Sep 11, 2013, at 4:57 AM, Coleen Phillmore <coleen.phillimore at oracle.com> wrote:
>
>> Hi,
>>
>> Have you done performance testing on this change?   When develop flags are not defined they are defined "const" false which enables the C++ compiler to do better optimizations.   I've seen code that counts on that.
>> If you want the values to be materialized, why not change the develop flag definition to be extern const (or some such).
> develop and notproduct flags are still constants; I didn't change that.  I've just put the const value in the flags table.

Ok.  That's fine then.  I hadn't read through the code change.
Coleen
>
> -- Chris
>
>> Coleen
>>
>> On 9/10/2013 8:56 PM, Christian Thalinger wrote:
>>> http://cr.openjdk.java.net/~twisti/8024545/webrev/
>>>
>>> 8024545: make develop and notproduct flag values available in product builds
>>> Reviewed-by:
>>>
>>> Right now the internal flag table only contains flags which are defined in a product build. This does not include develop and notproduct flags. Sometimes it is useful to have access to these values for post-mortem core file analysis or to read these values for compiler settings for a Java-based compiler.
>>>
>>> This change enables develop and notproduct flag values to be read by the serviceability agent. The binary size is increased by 42k for a 64-bit product build and by 32k for a 32-bit product build.
>>>
>>> Before:
>>>
>>> $ java -cp /java/re/jdk/8/latest/binaries/linux-x64/lib/sa-jdi.jar sun.jvm.hotspot.CLHSDB 9399
>>> Attaching to process 9399, please wait...
>>> hsdb> flags -nd
>>> InitialHeapSize = 495006528 5
>>> MaxHeapSize = 7920943104 5
>>> UseCompressedKlassPointers = true 5
>>> UseCompressedOops = true 5
>>> UseParallelGC = true 5
>>> hsdb> flags InlineMathNatives
>>> Couldn't find flag: InlineMathNatives
>>>
>>> After:
>>>
>>> $ java -cp $JAVA_HOME/lib/sa-jdi.jar sun.jvm.hotspot.CLHSDB 3726
>>> Attaching to process 3726, please wait...
>>> hsdb> flags -nd
>>> InitialHeapSize = 495006528 5
>>> MaxHeapSize = 7920943104 5
>>> UseCompressedKlassPointers = true 5
>>> UseCompressedOops = true 5
>>> UseParallelGC = true 5
>>> hsdb> flags InlineMathNatives
>>> InlineMathNatives = true 0
>>>
>>> This patch has one behavioral difference; when printing flags with e.g. PrintFlagsFinal in a debug build it prints "develop" for develop flags:
>>>
>>>      uintx AdaptiveSizePolicyGCTimeLimitThreshold    = 5               {develop}
>>>
>>> The output for product builds is unchanged.