Add a IsInitialized check in AOT code with clinit at entry checks.
The investigations behind
https://android-review.googlesource.com/c/platform/art/+/2214701 showed
that it can take some time for a class to become visibly initialized. To
avoid a busy loop between the AOT code and the resolution trampoline, we
also add a isInitialized check, which if true will be followed by a
memory barrier and the execution of the compiled code.
Test: test.py
Bug: 162110941
Change-Id: I6c36cde6ebd12b1f81281eb8a684b496f266e3ea
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index 6b85aaa..578a341 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -68,6 +68,8 @@
enum_cast<uint32_t>(ClassStatus::kVisiblyInitialized) << (status_lsb_position % kBitsPerByte);
constexpr uint32_t shifted_initializing_value =
enum_cast<uint32_t>(ClassStatus::kInitializing) << (status_lsb_position % kBitsPerByte);
+constexpr uint32_t shifted_initialized_value =
+ enum_cast<uint32_t>(ClassStatus::kInitialized) << (status_lsb_position % kBitsPerByte);
class Assembler;
class CodeGenerator;
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 17407a5..7fb6d3c 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -1242,6 +1242,7 @@
if (GetCompilerOptions().ShouldCompileWithClinitCheck(GetGraph()->GetArtMethod())) {
UseScratchRegisterScope temps(masm);
vixl::aarch64::Label resolution;
+ vixl::aarch64::Label memory_barrier;
Register temp1 = temps.AcquireW();
Register temp2 = temps.AcquireW();
@@ -1255,6 +1256,11 @@
__ Cmp(temp2, shifted_visibly_initialized_value);
__ B(hs, &frame_entry_label_);
+ // Check if we're initialized and jump to code that does a memory barrier if
+ // so.
+ __ Cmp(temp2, shifted_initialized_value);
+ __ B(hs, &memory_barrier);
+
// Check if we're initializing and the thread initializing is the one
// executing the code.
__ Cmp(temp2, shifted_initializing_value);
@@ -1271,6 +1277,9 @@
GetThreadOffset<kArm64PointerSize>(kQuickQuickResolutionTrampoline);
__ Ldr(temp1.X(), MemOperand(tr, entrypoint_offset.Int32Value()));
__ Br(temp1.X());
+
+ __ Bind(&memory_barrier);
+ GenerateMemoryBarrier(MemBarrierKind::kAnyAny);
}
__ Bind(&frame_entry_label_);
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 0850e2f..0753d36 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -2246,6 +2246,7 @@
if (GetCompilerOptions().ShouldCompileWithClinitCheck(GetGraph()->GetArtMethod())) {
UseScratchRegisterScope temps(GetVIXLAssembler());
vixl32::Label resolution;
+ vixl32::Label memory_barrier;
// Check if we're visibly initialized.
@@ -2265,6 +2266,11 @@
__ Cmp(temp2, shifted_visibly_initialized_value);
__ B(cs, &frame_entry_label_);
+ // Check if we're initialized and jump to code that does a memory barrier if
+ // so.
+ __ Cmp(temp2, shifted_initialized_value);
+ __ B(cs, &memory_barrier);
+
// Check if we're initializing and the thread initializing is the one
// executing the code.
__ Cmp(temp2, shifted_initializing_value);
@@ -2281,6 +2287,9 @@
GetThreadOffset<kArmPointerSize>(kQuickQuickResolutionTrampoline);
__ Ldr(temp1, MemOperand(tr, entrypoint_offset.Int32Value()));
__ Bx(temp1);
+
+ __ Bind(&memory_barrier);
+ GenerateMemoryBarrier(MemBarrierKind::kAnyAny);
}
__ Bind(&frame_entry_label_);