Object.clone() allocates more movable objects

Make Object.clone() allocate an unmovable object only if the original
was specifically allocated as nonmovable. Or at least get much closer
to that.

In the process, we stop allocated nonmovable objects in
LargeObjectsSpace, so that we can better identifty them.

Objects in image space cannot have been allocated as nonmovable:

newNonMovableArray() involves JNI call, and this will cause a
transaction failure. This is good, since the act of including the
object in an ImageSpace would move it.

The ZygoteSpace is allocated by copying objects into nonmoving space.
To avoid having clone() treat the whole ZygoteSpace as nonmovable, we
explicitly remember the non-class objects that were already there.
Currently we use a std::set data structure for this. This seems
a bit suboptimal; a sorted array may be an improvement. But empirically
the set only contains a dozen or two elements for AOSP.

We do implicitly allocate classes using the nonnmoving allocator. But
those cannot be cloned. Thus we do not bother tracking them.

For Array::CopyOf, we DCHECK that the argument was movable, and
fix one of the callers to fail in a more appropriate way if we
would otherwise violate that.

Prevent jvmti from resizing a nonmovable array. I don't think anything
good could have come of that anyway.

This should prevent us from creating unrequested nonmovable objects,
except as a result of the CC collector using that as a backup when it
otherwise runs out of space during copying.

Rename IsMovableObject() to somewhat clarify that it queries an
implementation property, where IsNonMovable() is a query about intended
object semantics, NOT implementation artifacts.

Various drive-by documentation fixes for issues I encountered while
trying to understand the code.

Bug: 355291033
Bug: 354087169
Test: Build and boot AOSP
Change-Id: Ia24dd1c2623d3d588c397332f87be45cc0f4bf27

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/optimizing/intrinsics.cc b/compiler/optimizing/intrinsics.cc
index b87f6f3975..8ae2494357 100644
--- a/compiler/optimizing/intrinsics.cc
+++ b/compiler/optimizing/intrinsics.cc
@@ -218,7 +218,7 @@ void IntrinsicVisitor::AssertNonMovableStringClass() {
   if (kIsDebugBuild) {
     ScopedObjectAccess soa(Thread::Current());
     ObjPtr<mirror::Class> string_class = GetClassRoot<mirror::String>();
-    CHECK(!art::Runtime::Current()->GetHeap()->IsMovableObject(string_class));
+    CHECK(!art::Runtime::Current()->GetHeap()->ObjectMayMove(string_class));
   }
 }