Since JRuby-9.0.0.0 changes to classloaders are failing ruby-processing #3152
Description
JRuby is losing the magic that let ruby-processing just work:-
To make ruby-processing work it is important that ruby and java classes can be added somewhat dynamically (including those with native binaries), the recent changes to the class loaders in JRuby-9.0.0.0 are making it all but impossible to combine say video libraries (incorporating gstreamer and the like) and graphics (OPENGL). In some ways this is a continuation the issue that I reported earlier #3036 which can be fixed for simple cases by loading the jars onto the java classpath. Now if there were a new way of doing this, but incompatible with the old way I would be very interested as I am trying to create a new version of ruby-processing JRubyArt. Here is what I currently have to do add video library to JRubyArt (this is hard coded in the app and OK for core libraries.
def video
Dir["#{Processing::RP_CONFIG['sketchbook_path']}/libraries/video/library/\*.jar"]
endpreviously with ruby-processing we were able to add the jars from ruby and in our library _loader used the following hack to load the native binaries (even when not in a jar)
# HACK: For pure java libraries, such as the ones that are available
# on this page: http://processing.org/reference/libraries/index.html
# that include native code, we mess with the 'Java ClassLoader', so that
# you don't have to futz with your PATH. But it's probably bad juju.
def load_java_library(library_name)
library_name = library_name.to_sym
return true if @loaded_libraries.include?(library_name)
jpath = get_library_directory_path(library_name, 'jar')
jars = get_library_paths(library_name, 'jar')
return false if jars.empty?
jars.each { |jar| require jar }
platform_specific_library_paths = get_platform_specific_library_paths(jpath)
platform_specific_library_paths = platform_specific_library_paths.select do |ppath|
FileTest.directory?(ppath) && !Dir.glob(File.join(ppath, '*.{so,dll,jnilib}')).empty?
end
unless platform_specific_library_paths.empty?
platform_specific_library_paths << java.lang.System.getProperty('java.library.path')
new_library_path = platform_specific_library_paths.join(java.io.File.pathSeparator)
java.lang.System.setProperty('java.library.path', new_library_path)
field = java.lang.Class.for_name('java.lang.ClassLoader').get_declared_field('sys_paths')
if field
field.accessible = true
field.set(java.lang.Class.for_name('java.lang.System').get_class_loader, nil)
end
end
@loaded_libraries[library_name] = true
end