| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * 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 |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * 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. |
| */ |
| |
| #ifndef ART_RUNTIME_JNI_JNI_ID_MANAGER_H_ |
| #define ART_RUNTIME_JNI_JNI_ID_MANAGER_H_ |
| |
| #include <atomic> |
| #include <jni.h> |
| #include <vector> |
| |
| #include "art_field.h" |
| #include "art_method.h" |
| #include "base/mutex.h" |
| #include "jni_id_type.h" |
| #include "reflective_value_visitor.h" |
| |
| namespace art { |
| namespace jni { |
| |
| class ScopedEnableSuspendAllJniIdQueries; |
| class JniIdManager { |
| public: |
| template <typename T, |
| typename = typename std::enable_if<std::is_same_v<T, jmethodID> || |
| std::is_same_v<T, jfieldID>>> |
| static constexpr bool IsIndexId(T val) { |
| return val == nullptr || reinterpret_cast<uintptr_t>(val) % 2 == 1; |
| } |
| |
| ArtMethod* DecodeMethodId(jmethodID method) REQUIRES(!Locks::jni_id_lock_); |
| ArtField* DecodeFieldId(jfieldID field) REQUIRES(!Locks::jni_id_lock_); |
| jmethodID EncodeMethodId(ArtMethod* method) REQUIRES(!Locks::jni_id_lock_) |
| REQUIRES_SHARED(Locks::mutator_lock_); |
| jfieldID EncodeFieldId(ArtField* field) REQUIRES(!Locks::jni_id_lock_) |
| REQUIRES_SHARED(Locks::mutator_lock_); |
| |
| void VisitReflectiveTargets(ReflectiveValueVisitor* rvv) |
| REQUIRES(Locks::mutator_lock_, !Locks::jni_id_lock_); |
| |
| private: |
| template <typename ArtType> |
| uintptr_t EncodeGenericId(ArtType* t) REQUIRES(!Locks::jni_id_lock_) |
| REQUIRES_SHARED(Locks::mutator_lock_); |
| template <typename ArtType> |
| ArtType* DecodeGenericId(uintptr_t input) REQUIRES(!Locks::jni_id_lock_); |
| template <typename ArtType> std::vector<ArtType*>& GetGenericMap() REQUIRES(Locks::jni_id_lock_); |
| template <typename ArtType> |
| uintptr_t GetNextId(JniIdType id, ArtType* t) REQUIRES(Locks::jni_id_lock_); |
| template <typename ArtType> |
| size_t GetLinearSearchStartId(ArtType* t) REQUIRES(Locks::jni_id_lock_); |
| |
| void StartDefer() REQUIRES(!Locks::jni_id_lock_) REQUIRES_SHARED(Locks::mutator_lock_); |
| void EndDefer() REQUIRES(!Locks::jni_id_lock_) REQUIRES_SHARED(Locks::mutator_lock_); |
| |
| uintptr_t next_method_id_ GUARDED_BY(Locks::jni_id_lock_) = 1u; |
| std::vector<ArtMethod*> method_id_map_ GUARDED_BY(Locks::jni_id_lock_); |
| uintptr_t next_field_id_ GUARDED_BY(Locks::jni_id_lock_) = 1u; |
| std::vector<ArtField*> field_id_map_ GUARDED_BY(Locks::jni_id_lock_); |
| |
| // If non-zero indicates that some thread is trying to allocate ids without being able to update |
| // the method->id mapping (due to not being able to allocate or something). In this case decode |
| // and encode need to do a linear scan of the lists. The ScopedEnableSuspendAllJniIdQueries struct |
| // will deal with fixing everything up. |
| size_t deferred_allocation_refcount_ GUARDED_BY(Locks::jni_id_lock_) = 0; |
| // min jmethodID that might not have it's method->id mapping filled in. |
| uintptr_t deferred_allocation_method_id_start_ GUARDED_BY(Locks::jni_id_lock_) = 0u; |
| // min jfieldID that might not have it's field->id mapping filled in. |
| uintptr_t deferred_allocation_field_id_start_ GUARDED_BY(Locks::jni_id_lock_) = 0u; |
| |
| friend class ScopedEnableSuspendAllJniIdQueries; |
| }; |
| |
| // A scope that will enable using the Encode/Decode JNI id functions with all threads suspended. |
| // This is required since normally we need to be able to allocate to encode new ids. This should |
| // only be used when absolutely required, for example to invoke user-callbacks during heap walking |
| // or similar. |
| class ScopedEnableSuspendAllJniIdQueries { |
| public: |
| ScopedEnableSuspendAllJniIdQueries() REQUIRES_SHARED(Locks::mutator_lock_); |
| ~ScopedEnableSuspendAllJniIdQueries() REQUIRES_SHARED(Locks::mutator_lock_); |
| |
| private: |
| JniIdManager* manager_; |
| }; |
| |
| } // namespace jni |
| } // namespace art |
| |
| #endif // ART_RUNTIME_JNI_JNI_ID_MANAGER_H_ |