RFR: 7134701 [macosx] Support legacy native library names

[Michael McMahon]

On 28/03/12 08:40, Alan Bateman wrote:
> On 28/03/2012 04:51, Scott Kovatch wrote:
>> With this patch in place I can load the applet at Runescape.com now. 
>> I can't log in yet due to an AWT bug I probably haven't patched yet, 
>> but this is better than what it was.
>>
>> Minecraft.net is still giving me problems because it's bailing out 
>> before this change takes place. Here's the method in question:
>>
>> private static void doLoadLibrary(final String lib_name) {
>>     AccessController.doPrivileged(new PrivilegedAction<Object>() {
>>         public Object run() {
>>             String library_path = 
>> System.getProperty("org.lwjgl.librarypath");
>>             if (library_path != null) {
>>                 System.load(library_path + File.separator +
>>                     System.mapLibraryName(lib_name));
>>             } else {
>>                 System.loadLibrary(lib_name);
>>             }
>>             return null;
>>         }
>>     });
>> }
>>
>> It's failing because System.mapLibraryName is constructing a library 
>> named liblwjgl.dylib, but lwjgl only has 'liblwjgl.jnilib'. Apple's 
>> JDK 6 (and I suspect macosx-port) gives me 'liblwjgl.jnilib' for 
>> System.mapLibraryName("lwjgl").
>>
>> I can't even get this far with Apple's JDK 6 on minecraft.net, so 
>> it's hard to say this is a pure regression. I'm hesitant to suggest 
>> that we have mapLibraryName start returning a library named 
>> lib<xxx>.jnilib at this point.
>>
>> Any ideas for a workaround? I think your ClassLoader/System change 
>> shown here should still go in, but in this particular case we still 
>> have problems. I don't know how much code is out there that uses 
>> mapLibraryName in this way.
>>
>> -- Scott
> I just checked a Mac OSX 10.6.8 system with 6u29 installed and 
> System.mapLibraryName("foo") returns foo.jnilib. Do you know if this 
> was always the case? If so then I think there is an argument to be 
> made that the default should be .jnilib and .dynlib be the fallback, 
> especially if it's going to break anyone using mapLibraryName (my 
> guess is that mapLibraryName usages are rare, at least compared to 
> System.loadLibrary).
>
> -Alan
>
>
>
Maybe, we should be doing what Dan Daugherty suggested yesterday and 
re-mapping the native
filename in the case where a full absolute path is passed in (which is 
the code-path
when System.load() is called above)

My reasoning (for rejecting that) was that an absolute path is a request 
for an explicit name
eg. System.load("/abs/path/libfoo.dylib") and it seems odd to go 
modifying the path that
the user provided (as opposed to the System.loadLibrary("foo") case, 
where we have to
construct the path internally). But, I hadn't considered the case above 
where the path
is constructed by calling System.mapLibraryName().

So, I think a better approach might be to just to check for the old 
".jnilib" suffix in all
the cases, rather than changing System.mapLibraryName(). Otherwise, 
we'll have an inconsistency
forever more between the output of that method and the library suffix 
that we want people
to use.

I've attached the jdk8 diffs for doing this.

- Michael
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