[optimizing] Add memory barriers in constructors when needed
If a class has final fields we must add a memory barrier before
returning from constructor. This makes sure the fields are visible to
other threads.
Bug: 19851497
Change-Id: If8c485092fc512efb9636cd568cb0543fb27688e
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 8a64d81..fff2906 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -520,8 +520,19 @@
UpdateLocal(instruction.VRegA(), current_block_->GetLastInstruction());
}
+static bool RequiresConstructorBarrier(const DexCompilationUnit& cu, const CompilerDriver& driver) {
+ Thread* self = Thread::Current();
+ return cu.IsConstructor()
+ && driver.RequiresConstructorBarrier(self, cu.GetDexFile(), cu.GetClassDefIndex());
+}
+
void HGraphBuilder::BuildReturn(const Instruction& instruction, Primitive::Type type) {
if (type == Primitive::kPrimVoid) {
+ // Note that we might insert redundant barriers when inlining `super` calls.
+ // TODO: add a data flow analysis to get rid of duplicate barriers.
+ if (RequiresConstructorBarrier(*dex_compilation_unit_, *compiler_driver_)) {
+ current_block_->AddInstruction(new (arena_) HMemoryBarrier(kStoreStore));
+ }
current_block_->AddInstruction(new (arena_) HReturnVoid());
} else {
HInstruction* value = LoadLocal(instruction.VRegA(), type);