Native allocation accounting
Added two new functions: registerNativeAllocation and registerNativeFree.
These functions should be used to let the GC know about native allocations
which are held live by Java objects and released in finalizers. GC are performed
or requested from within registerNativeAllocation when the total number of native
bytes accounted for exceeds a certain threshold. After a GC occurs in
registerNativeAllocation, finalizers are run so that the native memory is freed.
Added a test which shows how to use these functions.
Change-Id: I40f3c79e1c02d5008dec7d58d61c5bb97ec2fc1b
diff --git a/test/NativeAllocations/NativeAllocations.java b/test/NativeAllocations/NativeAllocations.java
new file mode 100644
index 0000000..9423b91
--- /dev/null
+++ b/test/NativeAllocations/NativeAllocations.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.lang.reflect.*;
+
+class NativeAllocations {
+ static Object nativeLock = new Object();
+ static int nativeBytes = 0;
+ static Object runtime;
+ static Method register_native_allocation;
+ static Method register_native_free;
+ static int maxMem = 64 * 1024 * 1024;
+
+ static class NativeAllocation {
+ private int bytes;
+
+ NativeAllocation(int bytes) throws Exception {
+ this.bytes = bytes;
+ register_native_allocation.invoke(runtime, bytes);
+ synchronized (nativeLock) {
+ nativeBytes += bytes;
+ if (nativeBytes > maxMem) {
+ throw new OutOfMemoryError();
+ }
+ }
+ }
+
+ protected void finalize() throws Exception {
+ synchronized (nativeLock) {
+ nativeBytes -= bytes;
+ }
+ register_native_free.invoke(runtime, bytes);
+ }
+ }
+
+ public static void main(String[] args) throws Exception {
+ Class<?> vm_runtime = Class.forName("dalvik.system.VMRuntime");
+ Method get_runtime = vm_runtime.getDeclaredMethod("getRuntime");
+ runtime = get_runtime.invoke(null);
+ register_native_allocation = vm_runtime.getDeclaredMethod("registerNativeAllocation", Integer.TYPE);
+ register_native_free = vm_runtime.getDeclaredMethod("registerNativeFree", Integer.TYPE);
+ int count = 16;
+ int size = 512 * 0x400;
+ int allocation_count = 256;
+ NativeAllocation[] allocations = new NativeAllocation[count];
+ for (int i = 0; i < allocation_count; ++i) {
+ allocations[i % count] = new NativeAllocation(size);
+ }
+ System.out.println("Test complete");
+ }
+}
+