Request for review- RFE 8005716

[Dean Long]

On 3/5/2013 8:13 PM, BILL PITTORE wrote:
> On 3/5/2013 7:36 PM, Dean Long wrote:
>> If JNI_ONLOAD_SYMBOLS contains something like "_JNI_OnLoad at 8" on 
>> Windows, you can't just
>> turn that into "_JNI_OnLoad at 8_" + <libname>.  I think it needs to be
>> "_JNI_OnLoad_"  + <libname> + "@8"
> I'll look into that. When I built for windows and ran our test, the 
> JNI_OnLoad_TestStaticLib was exported without the decoration just 
> based on the JNIEXPORT JNICALL specifiers on the function. I didn't do 
> anything special to export it. But I recall this problem from another 
> project.
> 1    0 00001014 JNI_OnLoad_TestStaticLib = 
> @ILT+15(?JNI_OnLoad_TestStaticLib@@YGHPAUJavaVM_@@PAX at Z)
>>
>> Looks like onLoadSymbols[] is unused in 
>> Java_java_lang_ClassLoader_00024NativeLibrary_findBuiltinLib().
> I'll remove that. I redid the call to findBuiltinJniFunction but 
> forgot to remove that.
>
>>
>> Instead of adding getProcessHandle(), why not add 
>> JVM_FindBuiltinLibraryEntry() instead?
>> This would make it easier to support table-lookup when runtime symbol 
>> information is missing or not
>> supported by the platform.
> Not sure I'm following you on this. Make JVM_FindBuiltinLibraryEntry() 
> an exported function in the VM? How does it find JNI_OnLoad_L? 

For Windows and Linux, it would use basically your same code, just 
refactored a little.
By the way, did you consider using the special RTLD_DEFAULT handle 
instead of
dlopen(NULL)?

> Via a table setup by the developer/build system when the library is 
> linked in?
>

Yes, in previous projects we did exactly that for more exotic OSes.

dl

> bill
>
>>
>> dl
>>
>> On 3/5/2013 3:05 PM, bill.pittore at oracle.com wrote:
>>> This request is tied to bugid 8005716 that deals with adding support 
>>> for statically linked JNI libraries.
>>>
>>> The JEP is here: http://openjdk.java.net/jeps/178
>>>
>>> The bug is here:http://bugs.sun.com/view_bug.do?bug_id=8005716
>>>
>>> The webrevs are here:
>>>
>>> http://cr.openjdk.java.net/~bpittore/8005716/jdk-webrev.00/
>>> http://cr.openjdk.java.net/~bpittore/8005716/hs-webrev.00/
>>>
>>> The main piece of functionality is to check for the presence of 
>>> JNI_OnLoad_libname to determine if the library specified by 
>>> 'libname' has been statically linked into the VM. If the symbol is 
>>> found, it is assumed that the library is linked in and will not be 
>>> dynamically loaded.
>>>
>>> thanks,
>>> bill
>>
>