Make class lookup lazy in jni_generator when using lazy method lookup.

base/android/jni_generator/jni_generator.py

Index: base/android/jni_generator/jni_generator.py
diff --git a/base/android/jni_generator/jni_generator.py b/base/android/jni_generator/jni_generator.py
index 88332fafd04bb8afc0526de8a3cf58e2fa5d7879..b06f49fe6a9bfeafe3009d03567fd0496a6543cd 100755
--- a/base/android/jni_generator/jni_generator.py
+++ b/base/android/jni_generator/jni_generator.py
@@ -1122,11 +1122,11 @@ static ${RETURN} ${NAME}(JNIEnv* env, ${PARAMS_IN_DECLARATION}) {"""
 
   def GetCalledByNativeValues(self, called_by_native):
     """Fills in necessary values for the CalledByNative methods."""
+    java_class = called_by_native.java_class_name or self.class_name
     if called_by_native.static or called_by_native.is_constructor:
       first_param_in_declaration = ''
-      first_param_in_call = ('g_%s_clazz' %
-                             (called_by_native.java_class_name or
-                              self.class_name))
+      first_param_in_call = self.GetClazzVariableNameTemplate().substitute({
+          'JAVA_CLASS': java_class })
     else:
       first_param_in_declaration = ', jobject obj'
       first_param_in_call = 'obj'
@@ -1160,7 +1160,7 @@ static ${RETURN} ${NAME}(JNIEnv* env, ${PARAMS_IN_DECLARATION}) {"""
       else:
         return_clause = 'return ret;'
     return {
-        'JAVA_CLASS': called_by_native.java_class_name or self.class_name,
+        'JAVA_CLASS': java_class,
         'RETURN_TYPE': return_type,
         'OPTIONAL_ERROR_RETURN': optional_error_return,
         'RETURN_DECLARATION': return_declaration,
@@ -1199,12 +1199,19 @@ ${FUNCTION_SIGNATURE} {""")
     function_header_with_unused_template = Template("""\
 ${FUNCTION_SIGNATURE} __attribute__ ((unused));
 ${FUNCTION_SIGNATURE} {""")
+    if self.options.native_exports:
+      local_clazz_init_template = Template("""
+  jclass clazz =
+    base::android::LazyGetClass(env, k${JAVA_CLASS}ClassPath, \
+                                &g_${JAVA_CLASS}_clazz); """)
+    else:
+      local_clazz_init_template = Template("")
     template = Template("""
 static base::subtle::AtomicWord g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME} = 0;
 ${FUNCTION_HEADER}
-  /* Must call RegisterNativesImpl()  */
+  /* Must call RegisterNativesImpl()  */${LOCAL_CLAZZ_INIT}
   CHECK_CLAZZ(env, ${FIRST_PARAM_IN_CALL},
-      g_${JAVA_CLASS}_clazz${OPTIONAL_ERROR_RETURN});
+      ${CLAZZ_VARIABLE_NAME}${OPTIONAL_ERROR_RETURN});
   jmethodID method_id =
     ${GET_METHOD_ID_IMPL}
   ${RETURN_DECLARATION}
@@ -1216,6 +1223,10 @@ ${FUNCTION_HEADER}
     values = self.GetCalledByNativeValues(called_by_native)
     values['FUNCTION_SIGNATURE'] = (
         function_signature_template.substitute(values))
+    values['LOCAL_CLAZZ_INIT'] = (
+        local_clazz_init_template.substitute(values))
+    values['CLAZZ_VARIABLE_NAME'] = (
+        self.GetClazzVariableNameTemplate().substitute(values))
     if called_by_native.system_class:
       values['FUNCTION_HEADER'] = (
           function_header_with_unused_template.substitute(values))
@@ -1223,6 +1234,12 @@ ${FUNCTION_HEADER}
       values['FUNCTION_HEADER'] = function_header_template.substitute(values)
     return template.substitute(values)
 
+  def GetClazzVariableNameTemplate(self):
+    if self.options.native_exports:
+      return Template('clazz')
+    else:
+      return Template('g_${JAVA_CLASS}_clazz')
+
   def GetKMethodArrayEntry(self, native):
     template = Template("""\
     { "native${NAME}", ${JNI_SIGNATURE}, reinterpret_cast<void*>(${NAME}) },""")
@@ -1263,18 +1280,28 @@ const char k${JAVA_CLASS}ClassPath[] = "${JNI_CLASS_PATH}";""")
       }
       ret += [template.substitute(values)]
     ret += ''
-    for clazz in called_by_native_classes:
-      template = Template("""\
+
+    java_class_global_type = 'jclass'
+    java_class_global_init = 'NULL'
+    if self.options.native_exports:
+      java_class_global_type = 'base::subtle::AtomicWord'
+      java_class_global_init = '0'
+    template = Template("""\
 // Leaking this jclass as we cannot use LazyInstance from some threads.
-jclass g_${JAVA_CLASS}_clazz = NULL;""")
+${JAVA_CLASS_GLOBAL_TYPE} g_${JAVA_CLASS}_clazz = ${JAVA_CLASS_GLOBAL_INIT};""")
+    for clazz in called_by_native_classes:
       values = {
           'JAVA_CLASS': clazz,
+          'JAVA_CLASS_GLOBAL_TYPE': java_class_global_type,
+          'JAVA_CLASS_GLOBAL_INIT': java_class_global_init,
       }
       ret += [template.substitute(values)]
     return '\n'.join(ret)
 
   def GetFindClasses(self):
     """Returns the imlementation of FindClass for all known classes."""
+    if self.options.native_exports:
+      return '\n'
     if self.init_native:
       template = Template("""\
   g_${JAVA_CLASS}_clazz = static_cast<jclass>(env->NewWeakGlobalRef(clazz));""")
@@ -1293,13 +1320,13 @@ jclass g_${JAVA_CLASS}_clazz = NULL;""")
     if self.options.eager_called_by_natives:
       template = Template("""\
 env->Get${STATIC_METHOD_PART}MethodID(
-      g_${JAVA_CLASS}_clazz,
+      ${CLAZZ_VARIABLE_NAME},
       "${JNI_NAME}", ${JNI_SIGNATURE});""")
     else:
       template = Template("""\
   base::android::MethodID::LazyGet<
       base::android::MethodID::TYPE_${STATIC}>(
-      env, g_${JAVA_CLASS}_clazz,
+      env, ${CLAZZ_VARIABLE_NAME},
       "${JNI_NAME}",
       ${JNI_SIGNATURE},
       &g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME});
@@ -1323,6 +1350,9 @@ env->Get${STATIC_METHOD_PART}MethodID(
         'STATIC_METHOD_PART': 'Static' if called_by_native.static else '',
         'JNI_SIGNATURE': signature,
     }
+    values['CLAZZ_VARIABLE_NAME'] = (
+        self.GetClazzVariableNameTemplate().substitute(values))
+
     return template.substitute(values)