Rewrite class table construction in ImageWriter.

Make sure that class tables in images are at maximum load
factor (full) and make that maximum load factor independent
of runtime parameters. As we pre-allocate a class table
buffer of the right size in ImageWriter, we also avoid
unnecessary resizing of the temporary class table.

Make sure that app image class tables are deterministic.
We previously just copied the class table from the app class
loader even though some entries may have been inserted there
during multi-threaded phases of the compilation, causing
non-deterministic contents based on insertion order.

Remove obsolete comment related to patchoat relocations.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: boots.
Bug: 175869411
Change-Id: I605048b639f67a5ed4b03eb8888cbaafa9ba4091

1 files changed, 8 insertions, 3 deletions

diff --git a/runtime/class_table_test.cc b/runtime/class_table_test.cc
index 5275c7ea95..642e10ac46 100644
--- a/runtime/class_table_test.cc
+++ b/runtime/class_table_test.cc
@@ -144,11 +144,16 @@ TEST_F(ClassTableTest, ClassTable) {
   table.Remove(descriptor_x);
   EXPECT_FALSE(table.Contains(h_X.Get()));
 
-  // Test that WriteToMemory and ReadFromMemory work.
+  // Test that reading a class set from memory works.
   table.Insert(h_X.Get());
-  const size_t count = table.WriteToMemory(nullptr);
+  ClassTable::ClassSet temp_set;
+  table.Visit([&temp_set](ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_) {
+    temp_set.insert(ClassTable::TableSlot(klass));
+    return true;
+  });
+  const size_t count = temp_set.WriteToMemory(nullptr);
   std::unique_ptr<uint8_t[]> buffer(new uint8_t[count]());
-  ASSERT_EQ(table.WriteToMemory(&buffer[0]), count);
+  ASSERT_EQ(temp_set.WriteToMemory(&buffer[0]), count);
   ClassTable table2;
   size_t count2 = table2.ReadFromMemory(&buffer[0]);
   EXPECT_EQ(count, count2);