/* * Copyright (C) 2008 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #pragma once #include #include //#include #include "../system_properties.h" #include "contexts.h" #include "contexts_pre_split.h" #include "contexts_serialized.h" #include "contexts_split.h" constexpr int PROP_FILENAME_MAX = 1024; class SystemProperties { public: friend struct LocalPropertyTestState; friend class SystemPropertiesTest; // Note that system properties are initialized before libc calls static initializers, so // doing any initialization in this constructor is an error. Even a Constructor that zero // initializes this class will clobber the previous property initialization. // We rely on the static SystemProperties in libc to be placed in .bss and zero initialized. SystemProperties() = default; // Special constructor for testing that also zero initializes the important members. explicit SystemProperties(bool initialized) : initialized_(initialized) { } BIONIC_DISALLOW_COPY_AND_ASSIGN(SystemProperties); bool Init(const char* filename); bool AreaInit(const char* filename, bool* fsetxattr_failed); uint32_t AreaSerial(); const prop_info* Find(const char* name); int Read(const prop_info* pi, char* name, char* value); void ReadCallback(const prop_info* pi, void (*callback)(void* cookie, const char* name, const char* value, uint32_t serial), void* cookie); int Get(const char* name, char* value); int Update(prop_info* pi, const char* value, unsigned int len); int Add(const char* name, unsigned int namelen, const char* value, unsigned int valuelen); int Delete(const char *name); uint32_t Serial(const prop_info* pi); uint32_t WaitAny(uint32_t old_serial); bool Wait(const prop_info* pi, uint32_t old_serial, uint32_t* new_serial_ptr, const timespec* relative_timeout); const prop_info* FindNth(unsigned n); int Foreach(void (*propfn)(const prop_info* pi, void* cookie), void* cookie); private: // We don't want to use new or malloc in properties (b/31659220), and we don't want to waste a // full page by using mmap(), so we set aside enough space to create any context of the three // contexts. static constexpr size_t kMaxContextsAlign = MAX(alignof(ContextsSerialized), MAX(alignof(ContextsSplit), alignof(ContextsPreSplit))); static constexpr size_t kMaxContextsSize = MAX(sizeof(ContextsSerialized), MAX(sizeof(ContextsSplit), sizeof(ContextsPreSplit))); alignas(kMaxContextsAlign) char contexts_data_[kMaxContextsSize]; Contexts* contexts_; bool initialized_; char property_filename_[PROP_FILENAME_MAX]; };