nitc: add GC pinning support to the Java FFI

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/src/ffi/java.nit b/src/ffi/java.nit
index eca32ac..1adb9c9 100644 (file)
--- a/src/ffi/java.nit
+++ b/src/ffi/java.nit
@@ -220,6 +220,9 @@ redef class MModule
                for cb in callbacks do
                        jni_methods.add_all(cb.jni_methods_declaration(self))
                end
+               for cb in callbacks_used_from_java.types do
+                       jni_methods.add_all(cb.jni_methods_declaration(self))
+               end
 
                var cf = new CFunction("void nit_ffi_with_java_register_natives(JNIEnv* env, jclass jclazz)")
                cf.exprs.add """
@@ -470,6 +473,38 @@ redef class MType
        # Used by `JavaLanguage::compile_extern_method` when calling JNI's `CallStatic*Method`.
        # This strategy is used by JNI to type the return of callbacks to Java.
        private fun jni_signature_alt: String do return "Int"
+
+       redef fun compile_callback_to_java(mmodule, mainmodule, ccu)
+       do
+               var java_file = mmodule.java_file
+               if java_file == null then return
+
+               for variation in ["incr", "decr"] do
+                       var friendly_name = "{mangled_cname}_{variation}_ref"
+
+                       # C
+                       var csignature = "void {mmodule.impl_java_class_name}_{friendly_name}(JNIEnv *env, jclass clazz, jint object)"
+                       var cf = new CFunction("JNIEXPORT {csignature}")
+                       cf.exprs.add "\tnitni_global_ref_{variation}((void*)(long)object);"
+                       ccu.add_non_static_local_function cf
+
+                       # Java
+                       java_file.class_content.add "private native static void {friendly_name}(int object);\n"
+               end
+       end
+
+       redef fun jni_methods_declaration(from_mmodule)
+       do
+               var arr = new Array[String]
+               for variation in ["incr", "decr"] do
+                       var friendly_name = "{mangled_cname}_{variation}_ref"
+                       var jni_format = "(I)V"
+                       var cname = "{from_mmodule.impl_java_class_name}_{friendly_name}"
+                       arr.add """{"{{{friendly_name}}}", "{{{jni_format}}}", {{{cname}}}}"""
+               end
+
+               return arr
+       end
 end
 
 redef class MClassType