1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef _INCLUDE_SYS__SYSTEM_PROPERTIES_H 30 #define _INCLUDE_SYS__SYSTEM_PROPERTIES_H 31 32 #include <sys/cdefs.h> 33 #include <stdint.h> 34 35 #ifndef _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_ 36 #error you should #include <sys/system_properties.h> instead 37 #endif 38 39 #include <sys/system_properties.h> 40 41 __BEGIN_DECLS 42 43 #define PROP_SERVICE_NAME "property_service" 44 #define PROP_FILENAME "/dev/__properties__" 45 46 #define PROP_MSG_SETPROP 1 47 #define PROP_MSG_SETPROP2 0x00020001 48 49 #define PROP_SUCCESS 0 50 #define PROP_ERROR_READ_CMD 0x0004 51 #define PROP_ERROR_READ_DATA 0x0008 52 #define PROP_ERROR_READ_ONLY_PROPERTY 0x000B 53 #define PROP_ERROR_INVALID_NAME 0x0010 54 #define PROP_ERROR_INVALID_VALUE 0x0014 55 #define PROP_ERROR_PERMISSION_DENIED 0x0018 56 #define PROP_ERROR_INVALID_CMD 0x001B 57 #define PROP_ERROR_HANDLE_CONTROL_MESSAGE 0x0020 58 #define PROP_ERROR_SET_FAILED 0x0024 59 60 /* 61 ** Map the property area from the specified filename. This 62 ** method is for testing only. 63 */ 64 int __system_property_set_filename(const char* __filename); 65 66 /* 67 ** Initialize the area to be used to store properties. Can 68 ** only be done by a single process that has write access to 69 ** the property area. 70 */ 71 int __system_property_area_init(void); 72 73 /* Read the global serial number of the system properties 74 ** 75 ** Called to predict if a series of cached __system_property_find 76 ** objects will have seen __system_property_serial values change. 77 ** But also aids the converse, as changes in the global serial can 78 ** also be used to predict if a failed __system_property_find 79 ** could in-turn now find a new object; thus preventing the 80 ** cycles of effort to poll __system_property_find. 81 ** 82 ** Typically called at beginning of a cache cycle to signal if _any_ possible 83 ** changes have occurred since last. If there is, one may check each individual 84 ** __system_property_serial to confirm dirty, or __system_property_find 85 ** to check if the property now exists. If a call to __system_property_add 86 ** or __system_property_update has completed between two calls to 87 ** __system_property_area_serial then the second call will return a larger 88 ** value than the first call. Beware of race conditions as changes to the 89 ** properties are not atomic, the main value of this call is to determine 90 ** whether the expensive __system_property_find is worth retrying to see if 91 ** a property now exists. 92 ** 93 ** Returns the serial number on success, -1 on error. 94 */ 95 uint32_t __system_property_area_serial(void); 96 97 /* Add a new system property. Can only be done by a single 98 ** process that has write access to the property area, and 99 ** that process must handle sequencing to ensure the property 100 ** does not already exist and that only one property is added 101 ** or updated at a time. 102 ** 103 ** Returns 0 on success, -1 if the property area is full. 104 */ 105 int __system_property_add(const char* __name, unsigned int __name_length, const char* __value, unsigned int __value_length); 106 107 /* Update the value of a system property returned by 108 ** __system_property_find. Can only be done by a single process 109 ** that has write access to the property area, and that process 110 ** must handle sequencing to ensure that only one property is 111 ** updated at a time. 112 ** 113 ** Returns 0 on success, -1 if the parameters are incorrect. 114 */ 115 int __system_property_update(prop_info* __pi, const char* __value, unsigned int __value_length); 116 117 /* Read the serial number of a system property returned by 118 ** __system_property_find. 119 ** 120 ** Returns the serial number on success, -1 on error. 121 */ 122 uint32_t __system_property_serial(const prop_info* __pi); 123 124 /* Initialize the system properties area in read only mode. 125 * Should be done by all processes that need to read system 126 * properties. 127 * 128 * Returns 0 on success, -1 otherwise. 129 */ 130 int __system_properties_init(void); 131 132 /* Deprecated: use __system_property_wait instead. */ 133 uint32_t __system_property_wait_any(uint32_t __old_serial); 134 135 __END_DECLS 136 137 #endif 138
