1edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project/* 2edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * Copyright (C) 2005 The Android Open Source Project 3edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * 4edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 5edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * you may not use this file except in compliance with the License. 6edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * You may obtain a copy of the License at 7edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * 8edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 9edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * 10edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 11edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 12edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * See the License for the specific language governing permissions and 14edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project * limitations under the License. 15edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project */ 16edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 17edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project#include <stdlib.h> 18edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project#include <string.h> 19edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 20edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project#include <utils/SharedBuffer.h> 21edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project#include <utils/Atomic.h> 22edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 23edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project// --------------------------------------------------------------------------- 24edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 25edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Projectnamespace android { 26edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 27edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source ProjectSharedBuffer* SharedBuffer::alloc(size_t size) 28edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 29edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project SharedBuffer* sb = static_cast<SharedBuffer *>(malloc(sizeof(SharedBuffer) + size)); 30edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (sb) { 31edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project sb->mRefs = 1; 32edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project sb->mSize = size; 33edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 34edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return sb; 35edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 36edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 37edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 38edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Projectssize_t SharedBuffer::dealloc(const SharedBuffer* released) 39edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 40edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (released->mRefs != 0) return -1; // XXX: invalid operation 41edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project free(const_cast<SharedBuffer*>(released)); 42edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return 0; 43edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 44edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 45edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source ProjectSharedBuffer* SharedBuffer::edit() const 46edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 47edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (onlyOwner()) { 48edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return const_cast<SharedBuffer*>(this); 49edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 50edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project SharedBuffer* sb = alloc(mSize); 51edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (sb) { 52edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project memcpy(sb->data(), data(), size()); 53edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project release(); 54edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 55edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return sb; 56edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 57edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 58edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source ProjectSharedBuffer* SharedBuffer::editResize(size_t newSize) const 59edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 60edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (onlyOwner()) { 61edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project SharedBuffer* buf = const_cast<SharedBuffer*>(this); 62edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (buf->mSize == newSize) return buf; 63edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project buf = (SharedBuffer*)realloc(buf, sizeof(SharedBuffer) + newSize); 64edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (buf != NULL) { 65edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project buf->mSize = newSize; 66edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return buf; 67edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 68edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 69edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project SharedBuffer* sb = alloc(newSize); 70edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (sb) { 71edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project const size_t mySize = mSize; 72edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project memcpy(sb->data(), data(), newSize < mySize ? newSize : mySize); 73edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project release(); 74edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 75edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return sb; 76edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 77edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 78edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source ProjectSharedBuffer* SharedBuffer::attemptEdit() const 79edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 80edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (onlyOwner()) { 81edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return const_cast<SharedBuffer*>(this); 82edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 83edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return 0; 84edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 85edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 86edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source ProjectSharedBuffer* SharedBuffer::reset(size_t new_size) const 87edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 88edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project // cheap-o-reset. 89edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project SharedBuffer* sb = alloc(new_size); 90edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (sb) { 91edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project release(); 92edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 93edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return sb; 94edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 95edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 96edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Projectvoid SharedBuffer::acquire() const { 97edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project android_atomic_inc(&mRefs); 98edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 99edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 100edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Projectint32_t SharedBuffer::release(uint32_t flags) const 101edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project{ 102edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project int32_t prev = 1; 103edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if (onlyOwner() || ((prev = android_atomic_dec(&mRefs)) == 1)) { 104edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project mRefs = 0; 105edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project if ((flags & eKeepStorage) == 0) { 106edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project free(const_cast<SharedBuffer*>(this)); 107edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 108edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project } 109edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project return prev; 110edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project} 111edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 112edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project 113edbf3b6af777b721cd2a1ef461947e51e88241e1The Android Open Source Project}; // namespace android 114