Avoid some read barriers in ClassTable.
And clean up ClassTable.
Test: m test-art-host-gtest
Test: testrunner.py --host --interpreter
Bug: 119486698
Change-Id: Ie413bc5a56eb548352ae1fed0976b75c44e0c0d4
diff --git a/runtime/class_table-inl.h b/runtime/class_table-inl.h
index 5f8a0b0..d07ad33 100644
--- a/runtime/class_table-inl.h
+++ b/runtime/class_table-inl.h
@@ -88,6 +88,10 @@
return true;
}
+inline bool ClassTable::TableSlot::IsNull() const {
+ return Read<kWithoutReadBarrier>() == nullptr;
+}
+
template<ReadBarrierOption kReadBarrierOption>
inline mirror::Class* ClassTable::TableSlot::Read() const {
const uint32_t before = data_.load(std::memory_order_relaxed);
@@ -127,11 +131,7 @@
inline ClassTable::TableSlot::TableSlot(ObjPtr<mirror::Class> klass, uint32_t descriptor_hash)
: data_(Encode(klass, MaskHash(descriptor_hash))) {
- if (kIsDebugBuild) {
- std::string temp;
- const uint32_t hash = ComputeModifiedUtf8Hash(klass->GetDescriptor(&temp));
- CHECK_EQ(descriptor_hash, hash);
- }
+ DCHECK_EQ(descriptor_hash, HashDescriptor(klass));
}
template <typename Filter>
diff --git a/runtime/class_table.cc b/runtime/class_table.cc
index 8d8e93a..58f3674 100644
--- a/runtime/class_table.cc
+++ b/runtime/class_table.cc
@@ -34,15 +34,7 @@
}
bool ClassTable::Contains(ObjPtr<mirror::Class> klass) {
- ReaderMutexLock mu(Thread::Current(), lock_);
- TableSlot slot(klass);
- for (ClassSet& class_set : classes_) {
- auto it = class_set.find(slot);
- if (it != class_set.end()) {
- return it->Read() == klass;
- }
- }
- return false;
+ return LookupByDescriptor(klass) == klass;
}
mirror::Class* ClassTable::LookupByDescriptor(ObjPtr<mirror::Class> klass) {
@@ -191,27 +183,35 @@
uint32_t ClassTable::ClassDescriptorHashEquals::operator()(const TableSlot& slot)
const {
std::string temp;
- return ComputeModifiedUtf8Hash(slot.Read()->GetDescriptor(&temp));
+ // No read barrier needed, we're reading a chain of constant references for comparison
+ // with null and retrieval of constant primitive data. See ReadBarrierOption.
+ return ComputeModifiedUtf8Hash(slot.Read<kWithoutReadBarrier>()->GetDescriptor(&temp));
}
bool ClassTable::ClassDescriptorHashEquals::operator()(const TableSlot& a,
const TableSlot& b) const {
+ // No read barrier needed, we're reading a chain of constant references for comparison
+ // with null and retrieval of constant primitive data. See ReadBarrierOption.
if (a.Hash() != b.Hash()) {
std::string temp;
- DCHECK(!a.Read()->DescriptorEquals(b.Read()->GetDescriptor(&temp)));
+ DCHECK(!a.Read<kWithoutReadBarrier>()->DescriptorEquals(
+ b.Read<kWithoutReadBarrier>()->GetDescriptor(&temp)));
return false;
}
std::string temp;
- return a.Read()->DescriptorEquals(b.Read()->GetDescriptor(&temp));
+ return a.Read<kWithoutReadBarrier>()->DescriptorEquals(
+ b.Read<kWithoutReadBarrier>()->GetDescriptor(&temp));
}
bool ClassTable::ClassDescriptorHashEquals::operator()(const TableSlot& a,
const DescriptorHashPair& b) const {
+ // No read barrier needed, we're reading a chain of constant references for comparison
+ // with null and retrieval of constant primitive data. See ReadBarrierOption.
if (!a.MaskedHashEquals(b.second)) {
- DCHECK(!a.Read()->DescriptorEquals(b.first));
+ DCHECK(!a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.first));
return false;
}
- return a.Read()->DescriptorEquals(b.first);
+ return a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.first);
}
uint32_t ClassTable::ClassDescriptorHashEquals::operator()(const DescriptorHashPair& pair) const {
diff --git a/runtime/class_table.h b/runtime/class_table.h
index 0b08041..26cd3ec 100644
--- a/runtime/class_table.h
+++ b/runtime/class_table.h
@@ -64,9 +64,7 @@
return *this;
}
- bool IsNull() const REQUIRES_SHARED(Locks::mutator_lock_) {
- return Read<kWithoutReadBarrier>() == nullptr;
- }
+ bool IsNull() const REQUIRES_SHARED(Locks::mutator_lock_);
uint32_t Hash() const {
return MaskHash(data_.load(std::memory_order_relaxed));
diff --git a/runtime/mirror/class-inl.h b/runtime/mirror/class-inl.h
index 3ee8bfe..992c8f3 100644
--- a/runtime/mirror/class-inl.h
+++ b/runtime/mirror/class-inl.h
@@ -845,7 +845,10 @@
return false;
}
++match;
- klass = klass->GetComponentType();
+ // No read barrier needed, we're reading a chain of constant references for comparison
+ // with null. Then we follow up below with reading constant references to read constant
+ // primitive data in both proxy and non-proxy paths. See ReadBarrierOption.
+ klass = klass->GetComponentType<kDefaultVerifyFlags, kWithoutReadBarrier>();
}
if (klass->IsPrimitive()) {
return strcmp(Primitive::Descriptor(klass->GetPrimitiveType()), match) == 0;
