[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/nodes.h b/compiler/optimizing/nodes.h
index 649038b..c3c35ac 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -19,6 +19,7 @@
#include "base/arena_containers.h"
#include "base/arena_object.h"
+#include "dex/compiler_enums.h"
#include "entrypoints/quick/quick_entrypoints_enum.h"
#include "handle.h"
#include "handle_scope.h"
@@ -718,6 +719,7 @@
M(LoadString, Instruction) \
M(Local, Instruction) \
M(LongConstant, Constant) \
+ M(MemoryBarrier, Instruction) \
M(MonitorOperation, Instruction) \
M(Mul, BinaryOperation) \
M(Neg, UnaryOperation) \
@@ -908,6 +910,12 @@
HUseListNode<T>* use_node_;
};
+// TODO: Add better documentation to this class and maybe refactor with more suggestive names.
+// - Has(All)SideEffects suggests that all the side effects are present but only ChangesSomething
+// flag is consider.
+// - DependsOn suggests that there is a real dependency between side effects but it only
+// checks DependendsOnSomething flag.
+//
// Represents the side effects an instruction may have.
class SideEffects : public ValueObject {
public:
@@ -3437,6 +3445,22 @@
DISALLOW_COPY_AND_ASSIGN(HCheckCast);
};
+class HMemoryBarrier : public HTemplateInstruction<0> {
+ public:
+ explicit HMemoryBarrier(MemBarrierKind barrier_kind)
+ : HTemplateInstruction(SideEffects::None()),
+ barrier_kind_(barrier_kind) {}
+
+ MemBarrierKind GetBarrierKind() { return barrier_kind_; }
+
+ DECLARE_INSTRUCTION(MemoryBarrier);
+
+ private:
+ const MemBarrierKind barrier_kind_;
+
+ DISALLOW_COPY_AND_ASSIGN(HMemoryBarrier);
+};
+
class HMonitorOperation : public HTemplateInstruction<1> {
public:
enum OperationKind {