Add more detail to rosalloc fragmentation OOME

Also include total number of free page bytes, space footprint, and
space max capacity.

Sample output:
Throwing OutOfMemoryError "Failed to allocate a 7012 byte allocation
with 103464 free bytes and 101KB until OOM; failed due to
fragmentation (required continguous free 8192 bytes, largest
contiguous free 4096 bytes, total free pages 4096 bytes, space
footprint 268435456 bytes, space max capacity 268435456 bytes)

Added a basic test to ensure the allocator coalesces properly.

Bug: 32997082

Test: test-art-host

Change-Id: I642b6ad34b98f6d98c10f242a6f6e926e0b42acc

1 files changed, 35 insertions, 0 deletions

diff --git a/test/080-oom-fragmentation/src/Main.java b/test/080-oom-fragmentation/src/Main.java
new file mode 100644
index 0000000000..cf2113906f
--- /dev/null
+++ b/test/080-oom-fragmentation/src/Main.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+public class Main {
+    public static void main(String[] args) {
+        // Reserve around 1/4 of the RAM for keeping objects live.
+        long maxMem = Runtime.getRuntime().maxMemory();
+        Object[] holder = new Object[(int)maxMem / 16];
+        int count = 0;
+        try {
+            while (true) {
+                holder[count++] = new Object[1025];  // A bit over one page.
+            }
+        } catch (OutOfMemoryError e) {}
+        for (int i = 0; i < count; ++i) {
+            holder[i] = null;
+        }
+        // Make sure the heap can handle allocating large object array. This makes sure that free
+        // pages are correctly coalesced together by the allocator.
+        holder[0] = new Object[(int)maxMem / 8];
+    }
+}