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Diffstat (limited to 'native/jni/src/utils/exclusive_ownership_pointer.h')
-rw-r--r-- | native/jni/src/utils/exclusive_ownership_pointer.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/native/jni/src/utils/exclusive_ownership_pointer.h b/native/jni/src/utils/exclusive_ownership_pointer.h new file mode 100644 index 000000000..081802e8b --- /dev/null +++ b/native/jni/src/utils/exclusive_ownership_pointer.h @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2013, 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 LATINIME_EXCLUSIVE_OWNERSHIP_POINTER_H +#define LATINIME_EXCLUSIVE_OWNERSHIP_POINTER_H + +#include "defines.h" + +namespace latinime { + +template<class T> +class ExclusiveOwnershipPointer { + public: + // This instance become an owner of the raw pointer. + AK_FORCE_INLINE ExclusiveOwnershipPointer(T *const rawPointer) + : mPointer(rawPointer), + mSharedOwnerPtr(new (ExclusiveOwnershipPointer<T> *)(this)) {} + + // Move the ownership. + AK_FORCE_INLINE ExclusiveOwnershipPointer(const ExclusiveOwnershipPointer<T> &pointer) + : mPointer(pointer.mPointer), mSharedOwnerPtr(pointer.mSharedOwnerPtr) { + transferOwnership(&pointer); + } + + AK_FORCE_INLINE ~ExclusiveOwnershipPointer() { + deletePointersIfHavingOwnership(); + } + + AK_FORCE_INLINE T *get() const { + return mPointer; + } + + private: + // This class allows to copy and ensures only one instance has the ownership of the + // managed pointer. + DISALLOW_DEFAULT_CONSTRUCTOR(ExclusiveOwnershipPointer); + DISALLOW_ASSIGNMENT_OPERATOR(ExclusiveOwnershipPointer); + + void transferOwnership(const ExclusiveOwnershipPointer<T> *const src) { + if (*mSharedOwnerPtr != src) { + AKLOGE("Failed to transfer the ownership because src is not the current owner." + "src: %p, owner: %p", src, *mSharedOwnerPtr); + ASSERT(false); + return; + } + // Transfer the ownership from src to this instance. + *mSharedOwnerPtr = this; + } + + void deletePointersIfHavingOwnership() { + if (mSharedOwnerPtr && *mSharedOwnerPtr == this) { + if (mPointer) { + if (DEBUG_DICT) { + AKLOGI("Releasing pointer: %p", mPointer); + } + delete mPointer; + } + delete mSharedOwnerPtr; + } + } + + T *mPointer; + // mSharedOwnerPtr points a shared memory space where the instance which has the ownership is + // stored. + ExclusiveOwnershipPointer<T> **mSharedOwnerPtr; +}; +} // namespace latinime +#endif /* LATINIME_EXCLUSIVE_OWNERSHIP_POINTER_H */ |