diff options
Diffstat (limited to 'libc/bionic/system_properties.c')
| -rw-r--r-- | libc/bionic/system_properties.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/libc/bionic/system_properties.c b/libc/bionic/system_properties.c new file mode 100644 index 0000000..5e3b9e7 --- /dev/null +++ b/libc/bionic/system_properties.c @@ -0,0 +1,171 @@ +/* + * 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; +} |