| /* |
| * 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. |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <stddef.h> |
| #include <errno.h> |
| |
| #include <sys/mman.h> |
| |
| #include <sys/socket.h> |
| #include <sys/un.h> |
| #include <sys/select.h> |
| #include <sys/types.h> |
| #include <netinet/in.h> |
| |
| #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_ |
| #include <sys/_system_properties.h> |
| |
| #include <sys/atomics.h> |
| |
| static const char property_service_name[] = PROP_SERVICE_NAME; |
| |
| static unsigned dummy_props = 0; |
| |
| prop_area *__system_property_area__ = (void*) &dummy_props; |
| |
| int __system_properties_init(void) |
| { |
| prop_area *pa; |
| int s, fd; |
| unsigned sz; |
| char *env; |
| |
| if(__system_property_area__ != ((void*) &dummy_props)) { |
| return 0; |
| } |
| |
| env = getenv("ANDROID_PROPERTY_WORKSPACE"); |
| if (!env) { |
| return -1; |
| } |
| fd = atoi(env); |
| env = strchr(env, ','); |
| if (!env) { |
| return -1; |
| } |
| sz = atoi(env + 1); |
| |
| pa = mmap(0, sz, PROT_READ, MAP_SHARED, fd, 0); |
| |
| if(pa == MAP_FAILED) { |
| return -1; |
| } |
| |
| if((pa->magic != PROP_AREA_MAGIC) || (pa->version != PROP_AREA_VERSION)) { |
| munmap(pa, sz); |
| return -1; |
| } |
| |
| __system_property_area__ = pa; |
| return 0; |
| } |
| |
| const prop_info *__system_property_find_nth(unsigned n) |
| { |
| prop_area *pa = __system_property_area__; |
| |
| if(n >= pa->count) { |
| return 0; |
| } else { |
| return TOC_TO_INFO(pa, pa->toc[n]); |
| } |
| } |
| |
| const prop_info *__system_property_find(const char *name) |
| { |
| prop_area *pa = __system_property_area__; |
| unsigned count = pa->count; |
| unsigned *toc = pa->toc; |
| unsigned len = strlen(name); |
| prop_info *pi; |
| |
| while(count--) { |
| unsigned entry = *toc++; |
| if(TOC_NAME_LEN(entry) != len) continue; |
| |
| pi = TOC_TO_INFO(pa, entry); |
| if(memcmp(name, pi->name, len)) continue; |
| |
| return pi; |
| } |
| |
| return 0; |
| } |
| |
| int __system_property_read(const prop_info *pi, char *name, char *value) |
| { |
| unsigned serial, len; |
| |
| for(;;) { |
| serial = pi->serial; |
| while(SERIAL_DIRTY(serial)) { |
| __futex_wait(&pi->serial, serial, 0); |
| serial = pi->serial; |
| } |
| len = SERIAL_VALUE_LEN(serial); |
| memcpy(value, pi->value, len + 1); |
| if(serial == pi->serial) { |
| if(name != 0) { |
| strcpy(name, pi->name); |
| } |
| return len; |
| } |
| } |
| } |
| |
| int __system_property_get(const char *name, char *value) |
| { |
| const prop_info *pi = __system_property_find(name); |
| |
| if(pi != 0) { |
| return __system_property_read(pi, 0, value); |
| } else { |
| value[0] = 0; |
| return 0; |
| } |
| } |
| |
| int __system_property_wait(const prop_info *pi) |
| { |
| unsigned n; |
| if(pi == 0) { |
| prop_area *pa = __system_property_area__; |
| n = pa->serial; |
| do { |
| __futex_wait(&pa->serial, n, 0); |
| } while(n == pa->serial); |
| } else { |
| n = pi->serial; |
| do { |
| __futex_wait(&pi->serial, n, 0); |
| } while(n == pi->serial); |
| } |
| return 0; |
| } |