RFR: 8034025 Remove JPLIS agent dependency on canonicalize_md.c

[Staffan Larsen]

On 6 mar 2014, at 14:41, Alan Bateman <Alan.Bateman at oracle.com> wrote:

> On 06/03/2014 13:29, Staffan Larsen wrote:
>> 
>> :
>> 
>> I’m not sure how these things work, but I’ve built and tested this on all platforms, so it seemed to work. I see that WIN_JAVA_LIB is already added on windows so perhaps that is why. I’ve changed the fix slightly to remove the -ljava from the windows LDFLAGS and verified that it builds and tests on all platforms.
> I'm sure the build group can advise on the best approach but I think what you have looks okay now .
> 
> 
>> 
>> This turned out to be a mistake. According to the JVMTI spec, the agent does not have access to the JNIEnv during Agent_OnLoad(). Since Canonicalize() does not use the value it didn’t matter what I sent to it.
>> 
>> I would like to continue sending NULL to Canonicalize() as the JNIEnv since there is no way I can get a correct env in           Agent_OnLoad. It would not be correct, but it would work.
>> 
>> The other option is to add a Canonicalize_NoEnv() function to libjava that does not take a JNIEnv parameter.
>> 
>> Thoughts on this?
> This looks okay to me. It does assume that the JNIEnv is not used so somewhat fragile but anyone tempted to change anything will find the issue quickly. One idea is to change the name of the parameter in jni_util.c to "unused", same thing in the function prototype/extern. At some point we should consider removing the parameter but that is somewhat disruptive in that it means hotspot changes at the same time.

Thanks. I’ll change the parameter name to “unused” before pushing.

/Staffan