1cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project/* 2cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * Copyright (C) 2005 The Android Open Source Project 3cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * 4cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 5cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * you may not use this file except in compliance with the License. 6cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * You may obtain a copy of the License at 7cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * 8cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 9cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * 10cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 11cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 12cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * See the License for the specific language governing permissions and 14cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project * limitations under the License. 15cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project */ 16cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 17cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project#include <stdlib.h> 18cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project#include <string.h> 19cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 20cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project#include <utils/SharedBuffer.h> 21cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project#include <utils/Atomic.h> 22cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 23cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project// --------------------------------------------------------------------------- 24cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 25cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Projectnamespace android { 26cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 27cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source ProjectSharedBuffer* SharedBuffer::alloc(size_t size) 28cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 29cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project SharedBuffer* sb = static_cast<SharedBuffer *>(malloc(sizeof(SharedBuffer) + size)); 30cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (sb) { 31cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project sb->mRefs = 1; 32cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project sb->mSize = size; 33cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 34cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return sb; 35cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 36cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 37cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 38cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Projectssize_t SharedBuffer::dealloc(const SharedBuffer* released) 39cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 40cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (released->mRefs != 0) return -1; // XXX: invalid operation 41cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project free(const_cast<SharedBuffer*>(released)); 42cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return 0; 43cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 44cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 45cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source ProjectSharedBuffer* SharedBuffer::edit() const 46cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 47cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (onlyOwner()) { 48cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return const_cast<SharedBuffer*>(this); 49cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 50cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project SharedBuffer* sb = alloc(mSize); 51cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (sb) { 52cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project memcpy(sb->data(), data(), size()); 53cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project release(); 54cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 55cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return sb; 56cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 57cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 58cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source ProjectSharedBuffer* SharedBuffer::editResize(size_t newSize) const 59cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 60cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (onlyOwner()) { 61cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project SharedBuffer* buf = const_cast<SharedBuffer*>(this); 62cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (buf->mSize == newSize) return buf; 63cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project buf = (SharedBuffer*)realloc(buf, sizeof(SharedBuffer) + newSize); 64cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (buf != NULL) { 65cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project buf->mSize = newSize; 66cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return buf; 67cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 68cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 69cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project SharedBuffer* sb = alloc(newSize); 70cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (sb) { 71cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project const size_t mySize = mSize; 72cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project memcpy(sb->data(), data(), newSize < mySize ? newSize : mySize); 73cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project release(); 74cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 75cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return sb; 76cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 77cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 78cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source ProjectSharedBuffer* SharedBuffer::attemptEdit() const 79cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 80cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (onlyOwner()) { 81cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return const_cast<SharedBuffer*>(this); 82cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 83cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return 0; 84cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 85cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 86cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source ProjectSharedBuffer* SharedBuffer::reset(size_t new_size) const 87cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 88cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project // cheap-o-reset. 89cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project SharedBuffer* sb = alloc(new_size); 90cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (sb) { 91cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project release(); 92cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 93cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return sb; 94cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 95cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 96cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Projectvoid SharedBuffer::acquire() const { 97cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project android_atomic_inc(&mRefs); 98cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 99cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 100cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Projectint32_t SharedBuffer::release(uint32_t flags) const 101cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project{ 102cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project int32_t prev = 1; 103cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if (onlyOwner() || ((prev = android_atomic_dec(&mRefs)) == 1)) { 104cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project mRefs = 0; 105cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project if ((flags & eKeepStorage) == 0) { 106cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project free(const_cast<SharedBuffer*>(this)); 107cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 108cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project } 109cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project return prev; 110cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project} 111cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 112cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project 113cbb1011c95e0c25c29e40e203a6a31bccd029da3The Android Open Source Project}; // namespace android 114