Restore DDMS recent allocation tracking's behavior
Make the allocation tracker mark recently allocated objects as roots,
so the allocation records are not swept. Because DDMS needs recent
allocation tracking records even for dead objects. This should fix
the flaky failures for 098-ddmc test, but it cannot pass GC stress
test (OOM). Re-enabled 098-ddmc for other tests.
There should be an option to not mark them as roots, when user only
needs HPROF dump with traces but not DDMS's recent allocation tracking.
Probably need to add a new JNI API function for this option.
There could be another way to keep a second list of recent allocation
records and maintain a type cache for them, so not to make the objects
roots. But it's more complex, and not sure which is better.
Also reduce memory usage for AllocRecordStackTrace objects, and change
default stack depth to 16. Rename the property that controls the stack
depth to "debug.allocTracker.maxStackDepth" so developer can change it.
Bug:20037135
Change-Id: Ic6b9ae87bdcda558be6f14ded8057e763439881c
diff --git a/test/098-ddmc/src/Main.java b/test/098-ddmc/src/Main.java
index 4914ba2..f41ff2a 100644
--- a/test/098-ddmc/src/Main.java
+++ b/test/098-ddmc/src/Main.java
@@ -43,24 +43,14 @@
System.out.println("Confirm when we overflow, we don't roll over to zero. b/17392248");
final int overflowAllocations = 64 * 1024; // Won't fit in unsigned 16-bit value.
- // TODO: Temporary fix. Keep the new objects live so they are not garbage collected.
- // This will cause OOM exception for GC stress tests. The root cause is changed behaviour of
- // getRecentAllocations(). Working on restoring its old behaviour. b/20037135
- Object[] objects = new Object[overflowAllocations];
for (int i = 0; i < overflowAllocations; i++) {
- objects[i] = new Object();
+ new Object();
}
Allocations after = new Allocations(DdmVmInternal.getRecentAllocations());
System.out.println("before < overflowAllocations=" + (before.numberOfEntries < overflowAllocations));
System.out.println("after > before=" + (after.numberOfEntries > before.numberOfEntries));
System.out.println("after.numberOfEntries=" + after.numberOfEntries);
- // TODO: Temporary fix as above. b/20037135
- objects = null;
- Runtime.getRuntime().gc();
- final int fillerStrings = 16 * 1024;
- String[] strings = new String[fillerStrings];
-
System.out.println("Disable and confirm back to empty");
DdmVmInternal.enableRecentAllocations(false);
System.out.println("status=" + DdmVmInternal.getRecentAllocationStatus());
@@ -76,8 +66,8 @@
System.out.println("Confirm we can reenable twice in a row without losing allocations");
DdmVmInternal.enableRecentAllocations(true);
System.out.println("status=" + DdmVmInternal.getRecentAllocationStatus());
- for (int i = 0; i < fillerStrings; i++) {
- strings[i] = new String("fnord");
+ for (int i = 0; i < 16 * 1024; i++) {
+ new String("fnord");
}
Allocations first = new Allocations(DdmVmInternal.getRecentAllocations());
DdmVmInternal.enableRecentAllocations(true);