ART: Refactor ObjectTagTable
Factor out the plain holder from the event handling.
Bug: 31385354
Bug: 31385027
Test: m test-art-host
Change-Id: If6af36e5275f8f1b924ab7dba1fb14f1ce2de8fe
diff --git a/runtime/openjdkjvmti/jvmti_weak_table-inl.h b/runtime/openjdkjvmti/jvmti_weak_table-inl.h
new file mode 100644
index 0000000..f67fffc
--- /dev/null
+++ b/runtime/openjdkjvmti/jvmti_weak_table-inl.h
@@ -0,0 +1,389 @@
+/* Copyright (C) 2017 The Android Open Source Project
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This file implements interfaces from the file jvmti.h. This implementation
+ * is licensed under the same terms as the file jvmti.h. The
+ * copyright and license information for the file jvmti.h follows.
+ *
+ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef ART_RUNTIME_OPENJDKJVMTI_JVMTI_WEAK_TABLE_INL_H_
+#define ART_RUNTIME_OPENJDKJVMTI_JVMTI_WEAK_TABLE_INL_H_
+
+#include "jvmti_weak_table.h"
+
+#include <limits>
+
+#include "art_jvmti.h"
+#include "base/logging.h"
+#include "gc/allocation_listener.h"
+#include "instrumentation.h"
+#include "jni_env_ext-inl.h"
+#include "jvmti_allocator.h"
+#include "mirror/class.h"
+#include "mirror/object.h"
+#include "runtime.h"
+#include "ScopedLocalRef.h"
+
+namespace openjdkjvmti {
+
+template <typename T>
+void JvmtiWeakTable<T>::Lock() {
+ allow_disallow_lock_.ExclusiveLock(art::Thread::Current());
+}
+template <typename T>
+void JvmtiWeakTable<T>::Unlock() {
+ allow_disallow_lock_.ExclusiveUnlock(art::Thread::Current());
+}
+template <typename T>
+void JvmtiWeakTable<T>::AssertLocked() {
+ allow_disallow_lock_.AssertHeld(art::Thread::Current());
+}
+
+template <typename T>
+void JvmtiWeakTable<T>::UpdateTableWithReadBarrier() {
+ update_since_last_sweep_ = true;
+
+ auto WithReadBarrierUpdater = [&](const art::GcRoot<art::mirror::Object>& original_root,
+ art::mirror::Object* original_obj ATTRIBUTE_UNUSED)
+ REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ return original_root.Read<art::kWithReadBarrier>();
+ };
+
+ UpdateTableWith<decltype(WithReadBarrierUpdater), kIgnoreNull>(WithReadBarrierUpdater);
+}
+
+template <typename T>
+bool JvmtiWeakTable<T>::GetTagSlowPath(art::Thread* self, art::mirror::Object* obj, T* result) {
+ // Under concurrent GC, there is a window between moving objects and sweeping of system
+ // weaks in which mutators are active. We may receive a to-space object pointer in obj,
+ // but still have from-space pointers in the table. Explicitly update the table once.
+ // Note: this will keep *all* objects in the table live, but should be a rare occurrence.
+ UpdateTableWithReadBarrier();
+ return GetTagLocked(self, obj, result);
+}
+
+template <typename T>
+bool JvmtiWeakTable<T>::Remove(art::mirror::Object* obj, /* out */ T* tag) {
+ art::Thread* self = art::Thread::Current();
+ art::MutexLock mu(self, allow_disallow_lock_);
+ Wait(self);
+
+ return RemoveLocked(self, obj, tag);
+}
+template <typename T>
+bool JvmtiWeakTable<T>::RemoveLocked(art::mirror::Object* obj, T* tag) {
+ art::Thread* self = art::Thread::Current();
+ allow_disallow_lock_.AssertHeld(self);
+ Wait(self);
+
+ return RemoveLocked(self, obj, tag);
+}
+
+template <typename T>
+bool JvmtiWeakTable<T>::RemoveLocked(art::Thread* self, art::mirror::Object* obj, T* tag) {
+ auto it = tagged_objects_.find(art::GcRoot<art::mirror::Object>(obj));
+ if (it != tagged_objects_.end()) {
+ if (tag != nullptr) {
+ *tag = it->second;
+ }
+ tagged_objects_.erase(it);
+ return true;
+ }
+
+ if (art::kUseReadBarrier && self->GetIsGcMarking() && !update_since_last_sweep_) {
+ // Under concurrent GC, there is a window between moving objects and sweeping of system
+ // weaks in which mutators are active. We may receive a to-space object pointer in obj,
+ // but still have from-space pointers in the table. Explicitly update the table once.
+ // Note: this will keep *all* objects in the table live, but should be a rare occurrence.
+
+ // Update the table.
+ UpdateTableWithReadBarrier();
+
+ // And try again.
+ return RemoveLocked(self, obj, tag);
+ }
+
+ // Not in here.
+ return false;
+}
+
+template <typename T>
+bool JvmtiWeakTable<T>::Set(art::mirror::Object* obj, T new_tag) {
+ art::Thread* self = art::Thread::Current();
+ art::MutexLock mu(self, allow_disallow_lock_);
+ Wait(self);
+
+ return SetLocked(self, obj, new_tag);
+}
+template <typename T>
+bool JvmtiWeakTable<T>::SetLocked(art::mirror::Object* obj, T new_tag) {
+ art::Thread* self = art::Thread::Current();
+ allow_disallow_lock_.AssertHeld(self);
+ Wait(self);
+
+ return SetLocked(self, obj, new_tag);
+}
+
+template <typename T>
+bool JvmtiWeakTable<T>::SetLocked(art::Thread* self, art::mirror::Object* obj, T new_tag) {
+ auto it = tagged_objects_.find(art::GcRoot<art::mirror::Object>(obj));
+ if (it != tagged_objects_.end()) {
+ it->second = new_tag;
+ return true;
+ }
+
+ if (art::kUseReadBarrier && self->GetIsGcMarking() && !update_since_last_sweep_) {
+ // Under concurrent GC, there is a window between moving objects and sweeping of system
+ // weaks in which mutators are active. We may receive a to-space object pointer in obj,
+ // but still have from-space pointers in the table. Explicitly update the table once.
+ // Note: this will keep *all* objects in the table live, but should be a rare occurrence.
+
+ // Update the table.
+ UpdateTableWithReadBarrier();
+
+ // And try again.
+ return SetLocked(self, obj, new_tag);
+ }
+
+ // New element.
+ auto insert_it = tagged_objects_.emplace(art::GcRoot<art::mirror::Object>(obj), new_tag);
+ DCHECK(insert_it.second);
+ return false;
+}
+
+template <typename T>
+void JvmtiWeakTable<T>::Sweep(art::IsMarkedVisitor* visitor) {
+ if (DoesHandleNullOnSweep()) {
+ SweepImpl<true>(visitor);
+ } else {
+ SweepImpl<false>(visitor);
+ }
+
+ // Under concurrent GC, there is a window between moving objects and sweeping of system
+ // weaks in which mutators are active. We may receive a to-space object pointer in obj,
+ // but still have from-space pointers in the table. We explicitly update the table then
+ // to ensure we compare against to-space pointers. But we want to do this only once. Once
+ // sweeping is done, we know all objects are to-space pointers until the next GC cycle,
+ // so we re-enable the explicit update for the next marking.
+ update_since_last_sweep_ = false;
+}
+
+template <typename T>
+template <bool kHandleNull>
+void JvmtiWeakTable<T>::SweepImpl(art::IsMarkedVisitor* visitor) {
+ art::Thread* self = art::Thread::Current();
+ art::MutexLock mu(self, allow_disallow_lock_);
+
+ auto IsMarkedUpdater = [&](const art::GcRoot<art::mirror::Object>& original_root ATTRIBUTE_UNUSED,
+ art::mirror::Object* original_obj) {
+ return visitor->IsMarked(original_obj);
+ };
+
+ UpdateTableWith<decltype(IsMarkedUpdater),
+ kHandleNull ? kCallHandleNull : kRemoveNull>(IsMarkedUpdater);
+}
+
+template <typename T>
+template <typename Updater, typename JvmtiWeakTable<T>::TableUpdateNullTarget kTargetNull>
+ALWAYS_INLINE inline void JvmtiWeakTable<T>::UpdateTableWith(Updater& updater) {
+ // We optimistically hope that elements will still be well-distributed when re-inserting them.
+ // So play with the map mechanics, and postpone rehashing. This avoids the need of a side
+ // vector and two passes.
+ float original_max_load_factor = tagged_objects_.max_load_factor();
+ tagged_objects_.max_load_factor(std::numeric_limits<float>::max());
+ // For checking that a max load-factor actually does what we expect.
+ size_t original_bucket_count = tagged_objects_.bucket_count();
+
+ for (auto it = tagged_objects_.begin(); it != tagged_objects_.end();) {
+ DCHECK(!it->first.IsNull());
+ art::mirror::Object* original_obj = it->first.template Read<art::kWithoutReadBarrier>();
+ art::mirror::Object* target_obj = updater(it->first, original_obj);
+ if (original_obj != target_obj) {
+ if (kTargetNull == kIgnoreNull && target_obj == nullptr) {
+ // Ignore null target, don't do anything.
+ } else {
+ T tag = it->second;
+ it = tagged_objects_.erase(it);
+ if (target_obj != nullptr) {
+ tagged_objects_.emplace(art::GcRoot<art::mirror::Object>(target_obj), tag);
+ DCHECK_EQ(original_bucket_count, tagged_objects_.bucket_count());
+ } else if (kTargetNull == kCallHandleNull) {
+ HandleNullSweep(tag);
+ }
+ continue; // Iterator was implicitly updated by erase.
+ }
+ }
+ it++;
+ }
+
+ tagged_objects_.max_load_factor(original_max_load_factor);
+ // TODO: consider rehash here.
+}
+
+template <typename T>
+template <typename Storage, class Allocator>
+struct JvmtiWeakTable<T>::ReleasableContainer {
+ using allocator_type = Allocator;
+
+ explicit ReleasableContainer(const allocator_type& alloc, size_t reserve = 10)
+ : allocator(alloc),
+ data(reserve > 0 ? allocator.allocate(reserve) : nullptr),
+ size(0),
+ capacity(reserve) {
+ }
+
+ ~ReleasableContainer() {
+ if (data != nullptr) {
+ allocator.deallocate(data, capacity);
+ capacity = 0;
+ size = 0;
+ }
+ }
+
+ Storage* Release() {
+ Storage* tmp = data;
+
+ data = nullptr;
+ size = 0;
+ capacity = 0;
+
+ return tmp;
+ }
+
+ void Resize(size_t new_capacity) {
+ CHECK_GT(new_capacity, capacity);
+
+ Storage* tmp = allocator.allocate(new_capacity);
+ DCHECK(tmp != nullptr);
+ if (data != nullptr) {
+ memcpy(tmp, data, sizeof(Storage) * size);
+ }
+ Storage* old = data;
+ data = tmp;
+ allocator.deallocate(old, capacity);
+ capacity = new_capacity;
+ }
+
+ void Pushback(const Storage& elem) {
+ if (size == capacity) {
+ size_t new_capacity = 2 * capacity + 1;
+ Resize(new_capacity);
+ }
+ data[size++] = elem;
+ }
+
+ Allocator allocator;
+ Storage* data;
+ size_t size;
+ size_t capacity;
+};
+
+template <typename T>
+jvmtiError JvmtiWeakTable<T>::GetTaggedObjects(jvmtiEnv* jvmti_env,
+ jint tag_count,
+ const T* tags,
+ jint* count_ptr,
+ jobject** object_result_ptr,
+ T** tag_result_ptr) {
+ if (tag_count < 0) {
+ return ERR(ILLEGAL_ARGUMENT);
+ }
+ if (tag_count > 0) {
+ for (size_t i = 0; i != static_cast<size_t>(tag_count); ++i) {
+ if (tags[i] == 0) {
+ return ERR(ILLEGAL_ARGUMENT);
+ }
+ }
+ }
+ if (tags == nullptr) {
+ return ERR(NULL_POINTER);
+ }
+ if (count_ptr == nullptr) {
+ return ERR(NULL_POINTER);
+ }
+
+ art::Thread* self = art::Thread::Current();
+ art::MutexLock mu(self, allow_disallow_lock_);
+ Wait(self);
+
+ art::JNIEnvExt* jni_env = self->GetJniEnv();
+
+ constexpr size_t kDefaultSize = 10;
+ size_t initial_object_size;
+ size_t initial_tag_size;
+ if (tag_count == 0) {
+ initial_object_size = (object_result_ptr != nullptr) ? tagged_objects_.size() : 0;
+ initial_tag_size = (tag_result_ptr != nullptr) ? tagged_objects_.size() : 0;
+ } else {
+ initial_object_size = initial_tag_size = kDefaultSize;
+ }
+ JvmtiAllocator<void> allocator(jvmti_env);
+ ReleasableContainer<jobject, JvmtiAllocator<jobject>> selected_objects(allocator,
+ initial_object_size);
+ ReleasableContainer<T, JvmtiAllocator<T>> selected_tags(allocator, initial_tag_size);
+
+ size_t count = 0;
+ for (auto& pair : tagged_objects_) {
+ bool select;
+ if (tag_count > 0) {
+ select = false;
+ for (size_t i = 0; i != static_cast<size_t>(tag_count); ++i) {
+ if (tags[i] == pair.second) {
+ select = true;
+ break;
+ }
+ }
+ } else {
+ select = true;
+ }
+
+ if (select) {
+ art::mirror::Object* obj = pair.first.template Read<art::kWithReadBarrier>();
+ if (obj != nullptr) {
+ count++;
+ if (object_result_ptr != nullptr) {
+ selected_objects.Pushback(jni_env->AddLocalReference<jobject>(obj));
+ }
+ if (tag_result_ptr != nullptr) {
+ selected_tags.Pushback(pair.second);
+ }
+ }
+ }
+ }
+
+ if (object_result_ptr != nullptr) {
+ *object_result_ptr = selected_objects.Release();
+ }
+ if (tag_result_ptr != nullptr) {
+ *tag_result_ptr = selected_tags.Release();
+ }
+ *count_ptr = static_cast<jint>(count);
+ return ERR(NONE);
+}
+
+} // namespace openjdkjvmti
+
+#endif // ART_RUNTIME_OPENJDKJVMTI_JVMTI_WEAK_TABLE_INL_H_
diff --git a/runtime/openjdkjvmti/jvmti_weak_table.h b/runtime/openjdkjvmti/jvmti_weak_table.h
new file mode 100644
index 0000000..ae36122
--- /dev/null
+++ b/runtime/openjdkjvmti/jvmti_weak_table.h
@@ -0,0 +1,219 @@
+/* Copyright (C) 2017 The Android Open Source Project
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This file implements interfaces from the file jvmti.h. This implementation
+ * is licensed under the same terms as the file jvmti.h. The
+ * copyright and license information for the file jvmti.h follows.
+ *
+ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef ART_RUNTIME_OPENJDKJVMTI_JVMTI_WEAK_TABLE_H_
+#define ART_RUNTIME_OPENJDKJVMTI_JVMTI_WEAK_TABLE_H_
+
+#include <unordered_map>
+
+#include "base/macros.h"
+#include "base/mutex.h"
+#include "gc/system_weak.h"
+#include "gc_root-inl.h"
+#include "globals.h"
+#include "jvmti.h"
+#include "mirror/object.h"
+#include "thread-inl.h"
+
+namespace openjdkjvmti {
+
+class EventHandler;
+
+// A system-weak container mapping objects to elements of the template type. This corresponds
+// to a weak hash map. For historical reasons the stored value is called "tag."
+template <typename T>
+class JvmtiWeakTable : public art::gc::SystemWeakHolder {
+ public:
+ JvmtiWeakTable()
+ : art::gc::SystemWeakHolder(kTaggingLockLevel),
+ update_since_last_sweep_(false) {
+ }
+
+ // Remove the mapping for the given object, returning whether such a mapping existed (and the old
+ // value).
+ bool Remove(art::mirror::Object* obj, /* out */ T* tag)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(!allow_disallow_lock_);
+ bool RemoveLocked(art::mirror::Object* obj, /* out */ T* tag)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ // Set the mapping for the given object. Returns true if this overwrites an already existing
+ // mapping.
+ virtual bool Set(art::mirror::Object* obj, T tag)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(!allow_disallow_lock_);
+ virtual bool SetLocked(art::mirror::Object* obj, T tag)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ // Return the value associated with the given object. Returns true if the mapping exists, false
+ // otherwise.
+ bool GetTag(art::mirror::Object* obj, /* out */ T* result)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(!allow_disallow_lock_) {
+ art::Thread* self = art::Thread::Current();
+ art::MutexLock mu(self, allow_disallow_lock_);
+ Wait(self);
+
+ return GetTagLocked(self, obj, result);
+ }
+ bool GetTagLocked(art::mirror::Object* obj, /* out */ T* result)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_) {
+ art::Thread* self = art::Thread::Current();
+ allow_disallow_lock_.AssertHeld(self);
+ Wait(self);
+
+ return GetTagLocked(self, obj, result);
+ }
+
+ // Sweep the container. DO NOT CALL MANUALLY.
+ void Sweep(art::IsMarkedVisitor* visitor)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(!allow_disallow_lock_);
+
+ // Return all objects that have a value mapping in tags.
+ jvmtiError GetTaggedObjects(jvmtiEnv* jvmti_env,
+ jint tag_count,
+ const T* tags,
+ /* out */ jint* count_ptr,
+ /* out */ jobject** object_result_ptr,
+ /* out */ T** tag_result_ptr)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(!allow_disallow_lock_);
+
+ // Locking functions, to allow coarse-grained locking and amortization.
+ void Lock() ACQUIRE(allow_disallow_lock_);
+ void Unlock() RELEASE(allow_disallow_lock_);
+ void AssertLocked() ASSERT_CAPABILITY(allow_disallow_lock_);
+
+ protected:
+ // Should HandleNullSweep be called when Sweep detects the release of an object?
+ virtual bool DoesHandleNullOnSweep() {
+ return false;
+ }
+ // If DoesHandleNullOnSweep returns true, this function will be called.
+ virtual void HandleNullSweep(T tag ATTRIBUTE_UNUSED) {}
+
+ private:
+ bool SetLocked(art::Thread* self, art::mirror::Object* obj, T tag)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ bool RemoveLocked(art::Thread* self, art::mirror::Object* obj, /* out */ T* tag)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ bool GetTagLocked(art::Thread* self, art::mirror::Object* obj, /* out */ T* result)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_) {
+ auto it = tagged_objects_.find(art::GcRoot<art::mirror::Object>(obj));
+ if (it != tagged_objects_.end()) {
+ *result = it->second;
+ return true;
+ }
+
+ // Performance optimization: To avoid multiple table updates, ensure that during GC we
+ // only update once. See the comment on the implementation of GetTagSlowPath.
+ if (art::kUseReadBarrier &&
+ self != nullptr &&
+ self->GetIsGcMarking() &&
+ !update_since_last_sweep_) {
+ return GetTagSlowPath(self, obj, result);
+ }
+
+ return false;
+ }
+
+ // Slow-path for GetTag. We didn't find the object, but we might be storing from-pointers and
+ // are asked to retrieve with a to-pointer.
+ bool GetTagSlowPath(art::Thread* self, art::mirror::Object* obj, /* out */ T* result)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ // Update the table by doing read barriers on each element, ensuring that to-space pointers
+ // are stored.
+ void UpdateTableWithReadBarrier()
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ template <bool kHandleNull>
+ void SweepImpl(art::IsMarkedVisitor* visitor)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(!allow_disallow_lock_);
+
+ enum TableUpdateNullTarget {
+ kIgnoreNull,
+ kRemoveNull,
+ kCallHandleNull
+ };
+
+ template <typename Updater, TableUpdateNullTarget kTargetNull>
+ void UpdateTableWith(Updater& updater)
+ REQUIRES_SHARED(art::Locks::mutator_lock_)
+ REQUIRES(allow_disallow_lock_);
+
+ template <typename Storage, class Allocator = std::allocator<T>>
+ struct ReleasableContainer;
+
+ struct HashGcRoot {
+ size_t operator()(const art::GcRoot<art::mirror::Object>& r) const
+ REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ return reinterpret_cast<uintptr_t>(r.Read<art::kWithoutReadBarrier>());
+ }
+ };
+
+ struct EqGcRoot {
+ bool operator()(const art::GcRoot<art::mirror::Object>& r1,
+ const art::GcRoot<art::mirror::Object>& r2) const
+ REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ return r1.Read<art::kWithoutReadBarrier>() == r2.Read<art::kWithoutReadBarrier>();
+ }
+ };
+
+ // The tag table is used when visiting roots. So it needs to have a low lock level.
+ static constexpr art::LockLevel kTaggingLockLevel =
+ static_cast<art::LockLevel>(art::LockLevel::kAbortLock + 1);
+
+ std::unordered_map<art::GcRoot<art::mirror::Object>,
+ T,
+ HashGcRoot,
+ EqGcRoot> tagged_objects_
+ GUARDED_BY(allow_disallow_lock_)
+ GUARDED_BY(art::Locks::mutator_lock_);
+ // To avoid repeatedly scanning the whole table, remember if we did that since the last sweep.
+ bool update_since_last_sweep_;
+};
+
+} // namespace openjdkjvmti
+
+#endif // ART_RUNTIME_OPENJDKJVMTI_JVMTI_WEAK_TABLE_H_
diff --git a/runtime/openjdkjvmti/object_tagging.cc b/runtime/openjdkjvmti/object_tagging.cc
index b27c2a3..4215588 100644
--- a/runtime/openjdkjvmti/object_tagging.cc
+++ b/runtime/openjdkjvmti/object_tagging.cc
@@ -33,355 +33,34 @@
#include <limits>
-#include "art_jvmti.h"
-#include "base/logging.h"
#include "events-inl.h"
-#include "gc/allocation_listener.h"
-#include "instrumentation.h"
-#include "jni_env_ext-inl.h"
-#include "jvmti_allocator.h"
-#include "mirror/class.h"
-#include "mirror/object.h"
-#include "runtime.h"
-#include "ScopedLocalRef.h"
+#include "jvmti_weak_table-inl.h"
namespace openjdkjvmti {
-void ObjectTagTable::Lock() {
- allow_disallow_lock_.ExclusiveLock(art::Thread::Current());
-}
-void ObjectTagTable::Unlock() {
- allow_disallow_lock_.ExclusiveUnlock(art::Thread::Current());
-}
-void ObjectTagTable::AssertLocked() {
- allow_disallow_lock_.AssertHeld(art::Thread::Current());
-}
-
-void ObjectTagTable::UpdateTableWithReadBarrier() {
- update_since_last_sweep_ = true;
-
- auto WithReadBarrierUpdater = [&](const art::GcRoot<art::mirror::Object>& original_root,
- art::mirror::Object* original_obj ATTRIBUTE_UNUSED)
- REQUIRES_SHARED(art::Locks::mutator_lock_) {
- return original_root.Read<art::kWithReadBarrier>();
- };
-
- UpdateTableWith<decltype(WithReadBarrierUpdater), kIgnoreNull>(WithReadBarrierUpdater);
-}
-
-bool ObjectTagTable::GetTagSlowPath(art::Thread* self, art::mirror::Object* obj, jlong* result) {
- // Under concurrent GC, there is a window between moving objects and sweeping of system
- // weaks in which mutators are active. We may receive a to-space object pointer in obj,
- // but still have from-space pointers in the table. Explicitly update the table once.
- // Note: this will keep *all* objects in the table live, but should be a rare occurrence.
- UpdateTableWithReadBarrier();
- return GetTagLocked(self, obj, result);
-}
-
-void ObjectTagTable::Add(art::mirror::Object* obj, jlong tag) {
- // Same as Set(), as we don't have duplicates in an unordered_map.
- Set(obj, tag);
-}
-
-bool ObjectTagTable::Remove(art::mirror::Object* obj, jlong* tag) {
- art::Thread* self = art::Thread::Current();
- art::MutexLock mu(self, allow_disallow_lock_);
- Wait(self);
-
- return RemoveLocked(self, obj, tag);
-}
-bool ObjectTagTable::RemoveLocked(art::mirror::Object* obj, jlong* tag) {
- art::Thread* self = art::Thread::Current();
- allow_disallow_lock_.AssertHeld(self);
- Wait(self);
-
- return RemoveLocked(self, obj, tag);
-}
-
-bool ObjectTagTable::RemoveLocked(art::Thread* self, art::mirror::Object* obj, jlong* tag) {
- auto it = tagged_objects_.find(art::GcRoot<art::mirror::Object>(obj));
- if (it != tagged_objects_.end()) {
- if (tag != nullptr) {
- *tag = it->second;
- }
- tagged_objects_.erase(it);
- return true;
- }
-
- if (art::kUseReadBarrier && self->GetIsGcMarking() && !update_since_last_sweep_) {
- // Under concurrent GC, there is a window between moving objects and sweeping of system
- // weaks in which mutators are active. We may receive a to-space object pointer in obj,
- // but still have from-space pointers in the table. Explicitly update the table once.
- // Note: this will keep *all* objects in the table live, but should be a rare occurrence.
-
- // Update the table.
- UpdateTableWithReadBarrier();
-
- // And try again.
- return RemoveLocked(self, obj, tag);
- }
-
- // Not in here.
- return false;
-}
+// Instantiate for jlong = JVMTI tags.
+template class JvmtiWeakTable<jlong>;
bool ObjectTagTable::Set(art::mirror::Object* obj, jlong new_tag) {
if (new_tag == 0) {
jlong tmp;
return Remove(obj, &tmp);
}
-
- art::Thread* self = art::Thread::Current();
- art::MutexLock mu(self, allow_disallow_lock_);
- Wait(self);
-
- return SetLocked(self, obj, new_tag);
+ return JvmtiWeakTable<jlong>::Set(obj, new_tag);
}
bool ObjectTagTable::SetLocked(art::mirror::Object* obj, jlong new_tag) {
if (new_tag == 0) {
jlong tmp;
return RemoveLocked(obj, &tmp);
}
-
- art::Thread* self = art::Thread::Current();
- allow_disallow_lock_.AssertHeld(self);
- Wait(self);
-
- return SetLocked(self, obj, new_tag);
+ return JvmtiWeakTable<jlong>::SetLocked(obj, new_tag);
}
-bool ObjectTagTable::SetLocked(art::Thread* self, art::mirror::Object* obj, jlong new_tag) {
- auto it = tagged_objects_.find(art::GcRoot<art::mirror::Object>(obj));
- if (it != tagged_objects_.end()) {
- it->second = new_tag;
- return true;
- }
-
- if (art::kUseReadBarrier && self->GetIsGcMarking() && !update_since_last_sweep_) {
- // Under concurrent GC, there is a window between moving objects and sweeping of system
- // weaks in which mutators are active. We may receive a to-space object pointer in obj,
- // but still have from-space pointers in the table. Explicitly update the table once.
- // Note: this will keep *all* objects in the table live, but should be a rare occurrence.
-
- // Update the table.
- UpdateTableWithReadBarrier();
-
- // And try again.
- return SetLocked(self, obj, new_tag);
- }
-
- // New element.
- auto insert_it = tagged_objects_.emplace(art::GcRoot<art::mirror::Object>(obj), new_tag);
- DCHECK(insert_it.second);
- return false;
+bool ObjectTagTable::DoesHandleNullOnSweep() {
+ return event_handler_->IsEventEnabledAnywhere(ArtJvmtiEvent::kObjectFree);
}
-
-void ObjectTagTable::Sweep(art::IsMarkedVisitor* visitor) {
- if (event_handler_->IsEventEnabledAnywhere(ArtJvmtiEvent::kObjectFree)) {
- SweepImpl<true>(visitor);
- } else {
- SweepImpl<false>(visitor);
- }
-
- // Under concurrent GC, there is a window between moving objects and sweeping of system
- // weaks in which mutators are active. We may receive a to-space object pointer in obj,
- // but still have from-space pointers in the table. We explicitly update the table then
- // to ensure we compare against to-space pointers. But we want to do this only once. Once
- // sweeping is done, we know all objects are to-space pointers until the next GC cycle,
- // so we re-enable the explicit update for the next marking.
- update_since_last_sweep_ = false;
-}
-
-template <bool kHandleNull>
-void ObjectTagTable::SweepImpl(art::IsMarkedVisitor* visitor) {
- art::Thread* self = art::Thread::Current();
- art::MutexLock mu(self, allow_disallow_lock_);
-
- auto IsMarkedUpdater = [&](const art::GcRoot<art::mirror::Object>& original_root ATTRIBUTE_UNUSED,
- art::mirror::Object* original_obj) {
- return visitor->IsMarked(original_obj);
- };
-
- UpdateTableWith<decltype(IsMarkedUpdater),
- kHandleNull ? kCallHandleNull : kRemoveNull>(IsMarkedUpdater);
-}
-
void ObjectTagTable::HandleNullSweep(jlong tag) {
event_handler_->DispatchEvent<ArtJvmtiEvent::kObjectFree>(nullptr, tag);
}
-template <typename T, ObjectTagTable::TableUpdateNullTarget kTargetNull>
-ALWAYS_INLINE inline void ObjectTagTable::UpdateTableWith(T& updater) {
- // We optimistically hope that elements will still be well-distributed when re-inserting them.
- // So play with the map mechanics, and postpone rehashing. This avoids the need of a side
- // vector and two passes.
- float original_max_load_factor = tagged_objects_.max_load_factor();
- tagged_objects_.max_load_factor(std::numeric_limits<float>::max());
- // For checking that a max load-factor actually does what we expect.
- size_t original_bucket_count = tagged_objects_.bucket_count();
-
- for (auto it = tagged_objects_.begin(); it != tagged_objects_.end();) {
- DCHECK(!it->first.IsNull());
- art::mirror::Object* original_obj = it->first.Read<art::kWithoutReadBarrier>();
- art::mirror::Object* target_obj = updater(it->first, original_obj);
- if (original_obj != target_obj) {
- if (kTargetNull == kIgnoreNull && target_obj == nullptr) {
- // Ignore null target, don't do anything.
- } else {
- jlong tag = it->second;
- it = tagged_objects_.erase(it);
- if (target_obj != nullptr) {
- tagged_objects_.emplace(art::GcRoot<art::mirror::Object>(target_obj), tag);
- DCHECK_EQ(original_bucket_count, tagged_objects_.bucket_count());
- } else if (kTargetNull == kCallHandleNull) {
- HandleNullSweep(tag);
- }
- continue; // Iterator was implicitly updated by erase.
- }
- }
- it++;
- }
-
- tagged_objects_.max_load_factor(original_max_load_factor);
- // TODO: consider rehash here.
-}
-
-template <typename T, class Allocator = std::allocator<T>>
-struct ReleasableContainer {
- using allocator_type = Allocator;
-
- explicit ReleasableContainer(const allocator_type& alloc, size_t reserve = 10)
- : allocator(alloc),
- data(reserve > 0 ? allocator.allocate(reserve) : nullptr),
- size(0),
- capacity(reserve) {
- }
-
- ~ReleasableContainer() {
- if (data != nullptr) {
- allocator.deallocate(data, capacity);
- capacity = 0;
- size = 0;
- }
- }
-
- T* Release() {
- T* tmp = data;
-
- data = nullptr;
- size = 0;
- capacity = 0;
-
- return tmp;
- }
-
- void Resize(size_t new_capacity) {
- CHECK_GT(new_capacity, capacity);
-
- T* tmp = allocator.allocate(new_capacity);
- DCHECK(tmp != nullptr);
- if (data != nullptr) {
- memcpy(tmp, data, sizeof(T) * size);
- }
- T* old = data;
- data = tmp;
- allocator.deallocate(old, capacity);
- capacity = new_capacity;
- }
-
- void Pushback(const T& elem) {
- if (size == capacity) {
- size_t new_capacity = 2 * capacity + 1;
- Resize(new_capacity);
- }
- data[size++] = elem;
- }
-
- Allocator allocator;
- T* data;
- size_t size;
- size_t capacity;
-};
-
-jvmtiError ObjectTagTable::GetTaggedObjects(jvmtiEnv* jvmti_env,
- jint tag_count,
- const jlong* tags,
- jint* count_ptr,
- jobject** object_result_ptr,
- jlong** tag_result_ptr) {
- if (tag_count < 0) {
- return ERR(ILLEGAL_ARGUMENT);
- }
- if (tag_count > 0) {
- for (size_t i = 0; i != static_cast<size_t>(tag_count); ++i) {
- if (tags[i] == 0) {
- return ERR(ILLEGAL_ARGUMENT);
- }
- }
- }
- if (tags == nullptr) {
- return ERR(NULL_POINTER);
- }
- if (count_ptr == nullptr) {
- return ERR(NULL_POINTER);
- }
-
- art::Thread* self = art::Thread::Current();
- art::MutexLock mu(self, allow_disallow_lock_);
- Wait(self);
-
- art::JNIEnvExt* jni_env = self->GetJniEnv();
-
- constexpr size_t kDefaultSize = 10;
- size_t initial_object_size;
- size_t initial_tag_size;
- if (tag_count == 0) {
- initial_object_size = (object_result_ptr != nullptr) ? tagged_objects_.size() : 0;
- initial_tag_size = (tag_result_ptr != nullptr) ? tagged_objects_.size() : 0;
- } else {
- initial_object_size = initial_tag_size = kDefaultSize;
- }
- JvmtiAllocator<void> allocator(jvmti_env);
- ReleasableContainer<jobject, JvmtiAllocator<jobject>> selected_objects(allocator, initial_object_size);
- ReleasableContainer<jlong, JvmtiAllocator<jlong>> selected_tags(allocator, initial_tag_size);
-
- size_t count = 0;
- for (auto& pair : tagged_objects_) {
- bool select;
- if (tag_count > 0) {
- select = false;
- for (size_t i = 0; i != static_cast<size_t>(tag_count); ++i) {
- if (tags[i] == pair.second) {
- select = true;
- break;
- }
- }
- } else {
- select = true;
- }
-
- if (select) {
- art::mirror::Object* obj = pair.first.Read<art::kWithReadBarrier>();
- if (obj != nullptr) {
- count++;
- if (object_result_ptr != nullptr) {
- selected_objects.Pushback(jni_env->AddLocalReference<jobject>(obj));
- }
- if (tag_result_ptr != nullptr) {
- selected_tags.Pushback(pair.second);
- }
- }
- }
- }
-
- if (object_result_ptr != nullptr) {
- *object_result_ptr = selected_objects.Release();
- }
- if (tag_result_ptr != nullptr) {
- *tag_result_ptr = selected_tags.Release();
- }
- *count_ptr = static_cast<jint>(count);
- return ERR(NONE);
-}
-
} // namespace openjdkjvmti
diff --git a/runtime/openjdkjvmti/object_tagging.h b/runtime/openjdkjvmti/object_tagging.h
index 0296f1a..b5a601c 100644
--- a/runtime/openjdkjvmti/object_tagging.h
+++ b/runtime/openjdkjvmti/object_tagging.h
@@ -1,17 +1,32 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
+/* Copyright (C) 2016 The Android Open Source Project
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ * This file implements interfaces from the file jvmti.h. This implementation
+ * is licensed under the same terms as the file jvmti.h. The
+ * copyright and license information for the file jvmti.h follows.
*
- * http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
*/
#ifndef ART_RUNTIME_OPENJDKJVMTI_OBJECT_TAGGING_H_
@@ -20,62 +35,27 @@
#include <unordered_map>
#include "base/mutex.h"
-#include "gc/system_weak.h"
-#include "gc_root-inl.h"
#include "globals.h"
#include "jvmti.h"
+#include "jvmti_weak_table.h"
#include "mirror/object.h"
-#include "thread-inl.h"
namespace openjdkjvmti {
class EventHandler;
-class ObjectTagTable : public art::gc::SystemWeakHolder {
+class ObjectTagTable FINAL : public JvmtiWeakTable<jlong> {
public:
- explicit ObjectTagTable(EventHandler* event_handler)
- : art::gc::SystemWeakHolder(kTaggingLockLevel),
- update_since_last_sweep_(false),
- event_handler_(event_handler) {
+ explicit ObjectTagTable(EventHandler* event_handler) : event_handler_(event_handler) {
}
- void Add(art::mirror::Object* obj, jlong tag)
+ bool Set(art::mirror::Object* obj, jlong tag) OVERRIDE
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(!allow_disallow_lock_);
-
- bool Remove(art::mirror::Object* obj, jlong* tag)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(!allow_disallow_lock_);
- bool RemoveLocked(art::mirror::Object* obj, jlong* tag)
+ bool SetLocked(art::mirror::Object* obj, jlong tag) OVERRIDE
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(allow_disallow_lock_);
- bool Set(art::mirror::Object* obj, jlong tag)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(!allow_disallow_lock_);
- bool SetLocked(art::mirror::Object* obj, jlong tag)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_);
-
- bool GetTag(art::mirror::Object* obj, jlong* result)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(!allow_disallow_lock_) {
- art::Thread* self = art::Thread::Current();
- art::MutexLock mu(self, allow_disallow_lock_);
- Wait(self);
-
- return GetTagLocked(self, obj, result);
- }
- bool GetTagLocked(art::mirror::Object* obj, jlong* result)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_) {
- art::Thread* self = art::Thread::Current();
- allow_disallow_lock_.AssertHeld(self);
- Wait(self);
-
- return GetTagLocked(self, obj, result);
- }
-
jlong GetTagOrZero(art::mirror::Object* obj)
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(!allow_disallow_lock_) {
@@ -91,108 +71,11 @@
return tmp;
}
- void Sweep(art::IsMarkedVisitor* visitor)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(!allow_disallow_lock_);
-
- jvmtiError GetTaggedObjects(jvmtiEnv* jvmti_env,
- jint tag_count,
- const jlong* tags,
- jint* count_ptr,
- jobject** object_result_ptr,
- jlong** tag_result_ptr)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(!allow_disallow_lock_);
-
- void Lock() ACQUIRE(allow_disallow_lock_);
- void Unlock() RELEASE(allow_disallow_lock_);
- void AssertLocked() ASSERT_CAPABILITY(allow_disallow_lock_);
+ protected:
+ bool DoesHandleNullOnSweep() OVERRIDE;
+ void HandleNullSweep(jlong tag) OVERRIDE;
private:
- bool SetLocked(art::Thread* self, art::mirror::Object* obj, jlong tag)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_);
-
- bool RemoveLocked(art::Thread* self, art::mirror::Object* obj, jlong* tag)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_);
-
- bool GetTagLocked(art::Thread* self, art::mirror::Object* obj, jlong* result)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_) {
- auto it = tagged_objects_.find(art::GcRoot<art::mirror::Object>(obj));
- if (it != tagged_objects_.end()) {
- *result = it->second;
- return true;
- }
-
- if (art::kUseReadBarrier &&
- self != nullptr &&
- self->GetIsGcMarking() &&
- !update_since_last_sweep_) {
- return GetTagSlowPath(self, obj, result);
- }
-
- return false;
- }
-
- // Slow-path for GetTag. We didn't find the object, but we might be storing from-pointers and
- // are asked to retrieve with a to-pointer.
- bool GetTagSlowPath(art::Thread* self, art::mirror::Object* obj, jlong* result)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_);
-
- // Update the table by doing read barriers on each element, ensuring that to-space pointers
- // are stored.
- void UpdateTableWithReadBarrier()
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_);
-
- template <bool kHandleNull>
- void SweepImpl(art::IsMarkedVisitor* visitor)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(!allow_disallow_lock_);
- void HandleNullSweep(jlong tag);
-
- enum TableUpdateNullTarget {
- kIgnoreNull,
- kRemoveNull,
- kCallHandleNull
- };
-
- template <typename T, TableUpdateNullTarget kTargetNull>
- void UpdateTableWith(T& updater)
- REQUIRES_SHARED(art::Locks::mutator_lock_)
- REQUIRES(allow_disallow_lock_);
-
- struct HashGcRoot {
- size_t operator()(const art::GcRoot<art::mirror::Object>& r) const
- REQUIRES_SHARED(art::Locks::mutator_lock_) {
- return reinterpret_cast<uintptr_t>(r.Read<art::kWithoutReadBarrier>());
- }
- };
-
- struct EqGcRoot {
- bool operator()(const art::GcRoot<art::mirror::Object>& r1,
- const art::GcRoot<art::mirror::Object>& r2) const
- REQUIRES_SHARED(art::Locks::mutator_lock_) {
- return r1.Read<art::kWithoutReadBarrier>() == r2.Read<art::kWithoutReadBarrier>();
- }
- };
-
- // The tag table is used when visiting roots. So it needs to have a low lock level.
- static constexpr art::LockLevel kTaggingLockLevel =
- static_cast<art::LockLevel>(art::LockLevel::kAbortLock + 1);
-
- std::unordered_map<art::GcRoot<art::mirror::Object>,
- jlong,
- HashGcRoot,
- EqGcRoot> tagged_objects_
- GUARDED_BY(allow_disallow_lock_)
- GUARDED_BY(art::Locks::mutator_lock_);
- // To avoid repeatedly scanning the whole table, remember if we did that since the last sweep.
- bool update_since_last_sweep_;
-
EventHandler* event_handler_;
};
