commit da7c650022a974be10e2f00fa07d5109e3d8826f
author Mathieu Chartier <mathieuc@google.com> Thu Jul 23 16:01:26 2015 -0700
committer Mathieu Chartier <mathieuc@google.com> Fri Jul 24 11:50:43 2015 -0700
tree eb713496fee4a6885a3c240309e5efc78c6774cf
parent 2a7ea34cda9bf776339dfc7f4a22ab01f9525f2d

Visit class native roots from VisitReferences

Visit class roots when we call Class::VisitReferences instead of in
the class linker. This makes it easier to implement class unloading
since unmarked classes won't have their roots visited by the class
linker.

Bug: 22181835
Change-Id: I63f31e5ebef7b2a0b764b3ba3cb038b3f561b379

runtime/gc/collector/semi_space.cc

diff --git a/runtime/gc/collector/semi_space.cc b/runtime/gc/collector/semi_space.cc
index e93ff05..acc1d9b 100644
--- a/runtime/gc/collector/semi_space.cc
+++ b/runtime/gc/collector/semi_space.cc
@@ -295,8 +295,26 @@
       LOG(FATAL) << ref << " found in from space";
     }
   }
+
+  // TODO: Remove NO_THREAD_SAFETY_ANALYSIS when clang better understands visitors.
+  void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root) const
+      NO_THREAD_SAFETY_ANALYSIS {
+    if (!root->IsNull()) {
+      VisitRoot(root);
+    }
+  }
+
+  void VisitRoot(mirror::CompressedReference<mirror::Object>* root) const
+      NO_THREAD_SAFETY_ANALYSIS {
+    if (kIsDebugBuild) {
+      Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
+      Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current());
+    }
+    CHECK(!from_space_->HasAddress(root->AsMirrorPtr()));
+  }
+
  private:
-  space::ContinuousMemMapAllocSpace* from_space_;
+  space::ContinuousMemMapAllocSpace* const from_space_;
 };
 
 void SemiSpace::VerifyNoFromSpaceReferences(Object* obj) {
@@ -313,6 +331,7 @@
     DCHECK(obj != nullptr);
     semi_space_->VerifyNoFromSpaceReferences(obj);
   }
+
  private:
   SemiSpace* const semi_space_;
 };
@@ -670,11 +689,27 @@
   }
 
   void operator()(mirror::Class* klass, mirror::Reference* ref) const
-      SHARED_REQUIRES(Locks::mutator_lock_)
-      REQUIRES(Locks::heap_bitmap_lock_) {
+      REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
     collector_->DelayReferenceReferent(klass, ref);
   }
 
+  // TODO: Remove NO_THREAD_SAFETY_ANALYSIS when clang better understands visitors.
+  void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root) const
+      NO_THREAD_SAFETY_ANALYSIS {
+    if (!root->IsNull()) {
+      VisitRoot(root);
+    }
+  }
+
+  void VisitRoot(mirror::CompressedReference<mirror::Object>* root) const
+      NO_THREAD_SAFETY_ANALYSIS {
+    if (kIsDebugBuild) {
+      Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
+      Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current());
+    }
+    collector_->MarkObject(root);
+  }
+
  private:
   SemiSpace* const collector_;
 };