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author | 2017-07-26 14:17:14 -0700 | |
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committer | 2017-07-31 07:38:43 -0700 | |
commit | 06c42a571358b5e5adb69104b183af8f32f4c07d (patch) | |
tree | 7b218fdb67fef74cdcbc2e3665757485ef89918b /openjdkjvmti/jvmti_weak_table-inl.h | |
parent | 7f14c2ec37c70010d99cab6806d85018df56c555 (diff) |
ART: Move openjdkjvmti to art/
Move libopenjdkjvmti out of the runtime directory. Let's not
pollute the runtime library.
Test: m test-art-host
Change-Id: Idb6b9cebcd61777bd3200437a2ae584a63a4a341
Diffstat (limited to 'openjdkjvmti/jvmti_weak_table-inl.h')
-rw-r--r-- | openjdkjvmti/jvmti_weak_table-inl.h | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/openjdkjvmti/jvmti_weak_table-inl.h b/openjdkjvmti/jvmti_weak_table-inl.h new file mode 100644 index 0000000000..1c82255fff --- /dev/null +++ b/openjdkjvmti/jvmti_weak_table-inl.h @@ -0,0 +1,406 @@ +/* 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_OPENJDKJVMTI_JVMTI_WEAK_TABLE_INL_H_ +#define ART_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 "nativehelper/ScopedLocalRef.h" +#include "runtime.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); +} + +template <typename T> +art::mirror::Object* JvmtiWeakTable<T>::Find(T tag) { + art::Thread* self = art::Thread::Current(); + art::MutexLock mu(self, allow_disallow_lock_); + Wait(self); + + for (auto& pair : tagged_objects_) { + if (tag == pair.second) { + art::mirror::Object* obj = pair.first.template Read<art::kWithReadBarrier>(); + if (obj != nullptr) { + return obj; + } + } + } + return nullptr; +} + +} // namespace openjdkjvmti + +#endif // ART_OPENJDKJVMTI_JVMTI_WEAK_TABLE_INL_H_ |