* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+#include <new>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>
+#include <sys/system_properties.h>
#include <sys/atomics.h>
#define ALIGN(x, a) (((x) + (a - 1)) & ~(a - 1))
-struct prop_area {
- unsigned bytes_used;
- unsigned volatile serial;
- unsigned magic;
- unsigned version;
- unsigned reserved[28];
- char data[0];
-};
-typedef struct prop_area prop_area;
-
-struct prop_info {
- unsigned volatile serial;
- char value[PROP_VALUE_MAX];
- char name[0];
-};
+static const char property_service_socket[] = "/dev/socket/" PROP_SERVICE_NAME;
-typedef struct prop_info prop_info;
/*
* Properties are stored in a hybrid trie/binary tree structure.
* +-----+ +-----+ +-----+ +===========+
*/
-typedef volatile uint32_t prop_off_t;
+// Represents a node in the trie.
struct prop_bt {
uint8_t namelen;
uint8_t reserved[3];
- prop_off_t prop;
+ volatile uint32_t prop;
- prop_off_t left;
- prop_off_t right;
+ volatile uint32_t left;
+ volatile uint32_t right;
- prop_off_t children;
+ volatile uint32_t children;
char name[0];
+
+ prop_bt(const char *name, const uint8_t name_length) {
+ this->namelen = name_length;
+ memcpy(this->name, name, name_length);
+ this->name[name_length] = '\0';
+ ANDROID_MEMBAR_FULL();
+ }
+
+private:
+ // Disallow copy and assign.
+ prop_bt(const prop_bt&);
+ prop_bt& operator=(const prop_bt&);
};
-typedef struct prop_bt prop_bt;
+struct prop_area {
+ uint32_t bytes_used;
+ volatile uint32_t serial;
+ uint32_t magic;
+ uint32_t version;
+ uint32_t reserved[28];
+ char data[0];
+
+ prop_area(const uint32_t magic, const uint32_t version) :
+ serial(0), magic(magic), version(version) {
+ memset(reserved, 0, sizeof(reserved));
+ // Allocate enough space for the root node.
+ bytes_used = sizeof(prop_bt);
+ }
+
+private:
+ // Disallow copy and assign.
+ prop_area(const prop_area&);
+ prop_area& operator=(const prop_area&);
+};
+
+struct prop_info {
+ volatile uint32_t serial;
+ char value[PROP_VALUE_MAX];
+ char name[0];
+
+ prop_info(const char *name, const uint8_t namelen, const char *value,
+ const uint8_t valuelen) {
+ memcpy(this->name, name, namelen);
+ this->name[namelen] = '\0';
+ this->serial = (valuelen << 24);
+ memcpy(this->value, value, valuelen);
+ this->value[valuelen] = '\0';
+ ANDROID_MEMBAR_FULL();
+ }
+private:
+ // Disallow copy and assign.
+ prop_info(const prop_info&);
+ prop_info& operator=(const prop_info&);
+};
+
+struct find_nth_cookie {
+ uint32_t count;
+ const uint32_t n;
+ const prop_info *pi;
+
+ find_nth_cookie(uint32_t n) : count(0), n(n), pi(NULL) {
+ }
+};
-static const char property_service_socket[] = "/dev/socket/" PROP_SERVICE_NAME;
static char property_filename[PATH_MAX] = PROP_FILENAME;
static bool compat_mode = false;
+static size_t pa_data_size;
+static size_t pa_size;
+// NOTE: This isn't static because system_properties_compat.c
+// requires it.
prop_area *__system_property_area__ = NULL;
-size_t pa_data_size;
-size_t pa_size;
-
static int get_fd_from_env(void)
{
+ // This environment variable consistes of two decimal integer
+ // values separated by a ",". The first value is a file descriptor
+ // and the second is the size of the system properties area. The
+ // size is currently unused.
char *env = getenv("ANDROID_PROPERTY_WORKSPACE");
if (!env) {
static int map_prop_area_rw()
{
- prop_area *pa;
- int fd;
- int ret;
-
/* dev is a tmpfs that we can use to carve a shared workspace
* out of, so let's do that...
*/
- fd = open(property_filename, O_RDWR | O_CREAT | O_NOFOLLOW | O_CLOEXEC |
- O_EXCL, 0444);
+ const int fd = open(property_filename,
+ O_RDWR | O_CREAT | O_NOFOLLOW | O_CLOEXEC | O_EXCL, 0444);
+
if (fd < 0) {
if (errno == EACCES) {
/* for consistency with the case where the process has already
return -1;
}
- ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
- if (ret < 0)
- goto out;
+ // TODO: Is this really required ? Does android run on any kernels that
+ // don't support O_CLOEXEC ?
+ const int ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ close(fd);
+ return -1;
+ }
- if (ftruncate(fd, PA_SIZE) < 0)
- goto out;
+ if (ftruncate(fd, PA_SIZE) < 0) {
+ close(fd);
+ return -1;
+ }
pa_size = PA_SIZE;
pa_data_size = pa_size - sizeof(prop_area);
compat_mode = false;
- pa = mmap(NULL, pa_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
- if(pa == MAP_FAILED)
- goto out;
+ void *const memory_area = mmap(NULL, pa_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (memory_area == MAP_FAILED) {
+ close(fd);
+ return -1;
+ }
- memset(pa, 0, pa_size);
- pa->magic = PROP_AREA_MAGIC;
- pa->version = PROP_AREA_VERSION;
- /* reserve root node */
- pa->bytes_used = sizeof(prop_bt);
+ prop_area *pa = new(memory_area) prop_area(PROP_AREA_MAGIC, PROP_AREA_VERSION);
/* plug into the lib property services */
__system_property_area__ = pa;
close(fd);
return 0;
-
-out:
- close(fd);
- return -1;
}
-int __system_property_set_filename(const char *filename)
-{
- size_t len = strlen(filename);
- if (len >= sizeof(property_filename))
+static int map_fd_ro(const int fd) {
+ struct stat fd_stat;
+ if (fstat(fd, &fd_stat) < 0) {
return -1;
+ }
- strcpy(property_filename, filename);
- return 0;
-}
+ if ((fd_stat.st_uid != 0)
+ || (fd_stat.st_gid != 0)
+ || ((fd_stat.st_mode & (S_IWGRP | S_IWOTH)) != 0)
+ || (fd_stat.st_size < sizeof(prop_area)) ) {
+ return -1;
+ }
-int __system_property_area_init()
-{
- return map_prop_area_rw();
+ pa_size = fd_stat.st_size;
+ pa_data_size = pa_size - sizeof(prop_area);
+
+ void* const map_result = mmap(NULL, pa_size, PROT_READ, MAP_SHARED, fd, 0);
+ if (map_result == MAP_FAILED) {
+ return -1;
+ }
+
+ prop_area* pa = reinterpret_cast<prop_area*>(map_result);
+ if ((pa->magic != PROP_AREA_MAGIC) || (pa->version != PROP_AREA_VERSION &&
+ pa->version != PROP_AREA_VERSION_COMPAT)) {
+ munmap(pa, pa_size);
+ return -1;
+ }
+
+ if (pa->version == PROP_AREA_VERSION_COMPAT) {
+ compat_mode = true;
+ }
+
+ __system_property_area__ = pa;
+ return 0;
}
static int map_prop_area()
{
- bool fromFile = true;
- int result = -1;
- int fd;
- int ret;
-
- fd = open(property_filename, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
+ int fd(open(property_filename, O_RDONLY | O_NOFOLLOW | O_CLOEXEC));
if (fd >= 0) {
/* For old kernels that don't support O_CLOEXEC */
- ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
- if (ret < 0)
- goto cleanup;
+ const int ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ close(fd);
+ return -1;
+ }
}
+ bool close_fd = true;
if ((fd < 0) && (errno == ENOENT)) {
/*
* For backwards compatibility, if the file doesn't
* condition.
*/
fd = get_fd_from_env();
- fromFile = false;
+ close_fd = false;
}
if (fd < 0) {
return -1;
}
- struct stat fd_stat;
- if (fstat(fd, &fd_stat) < 0) {
- goto cleanup;
- }
-
- if ((fd_stat.st_uid != 0)
- || (fd_stat.st_gid != 0)
- || ((fd_stat.st_mode & (S_IWGRP | S_IWOTH)) != 0)
- || (fd_stat.st_size < sizeof(prop_area)) ) {
- goto cleanup;
- }
-
- pa_size = fd_stat.st_size;
- pa_data_size = pa_size - sizeof(prop_area);
- prop_area *pa = mmap(NULL, pa_size, PROT_READ, MAP_SHARED, fd, 0);
-
- if (pa == MAP_FAILED) {
- goto cleanup;
- }
-
- if((pa->magic != PROP_AREA_MAGIC) || (pa->version != PROP_AREA_VERSION &&
- pa->version != PROP_AREA_VERSION_COMPAT)) {
- munmap(pa, pa_size);
- goto cleanup;
- }
-
- if (pa->version == PROP_AREA_VERSION_COMPAT) {
- compat_mode = true;
- }
-
- result = 0;
-
- __system_property_area__ = pa;
-
-cleanup:
- if (fromFile) {
+ const int map_result = map_fd_ro(fd);
+ if (close_fd) {
close(fd);
}
- return result;
+ return map_result;
}
-int __system_properties_init()
-{
- return map_prop_area();
-}
-
-static void *new_prop_obj(size_t size, prop_off_t *off)
+static void *allocate_obj(const size_t size, uint32_t *const off)
{
prop_area *pa = __system_property_area__;
- size = ALIGN(size, sizeof(uint32_t));
-
- if (pa->bytes_used + size > pa_data_size)
+ const size_t aligned = ALIGN(size, sizeof(uint32_t));
+ if (pa->bytes_used + aligned > pa_data_size) {
return NULL;
+ }
*off = pa->bytes_used;
- __system_property_area__->bytes_used += size;
- return __system_property_area__->data + *off;
+ pa->bytes_used += aligned;
+ return pa->data + *off;
}
-static prop_bt *new_prop_bt(const char *name, uint8_t namelen, prop_off_t *off)
+static prop_bt *new_prop_bt(const char *name, uint8_t namelen, uint32_t *const off)
{
- prop_off_t off_tmp;
- prop_bt *bt = new_prop_obj(sizeof(prop_bt) + namelen + 1, &off_tmp);
- if (bt) {
- memcpy(bt->name, name, namelen);
- bt->name[namelen] = '\0';
- bt->namelen = namelen;
- ANDROID_MEMBAR_FULL();
- *off = off_tmp;
+ uint32_t new_offset;
+ void *const offset = allocate_obj(sizeof(prop_bt) + namelen + 1, &new_offset);
+ if (offset) {
+ prop_bt* bt = new(offset) prop_bt(name, namelen);
+ *off = new_offset;
+ return bt;
}
- return bt;
+ return NULL;
}
static prop_info *new_prop_info(const char *name, uint8_t namelen,
- const char *value, uint8_t valuelen, prop_off_t *off)
+ const char *value, uint8_t valuelen, uint32_t *const off)
{
- prop_off_t off_tmp;
- prop_info *info = new_prop_obj(sizeof(prop_info) + namelen + 1, &off_tmp);
- if (info) {
- memcpy(info->name, name, namelen);
- info->name[namelen] = '\0';
- info->serial = (valuelen << 24);
- memcpy(info->value, value, valuelen);
- info->value[valuelen] = '\0';
- ANDROID_MEMBAR_FULL();
+ uint32_t off_tmp;
+ void* const offset = allocate_obj(sizeof(prop_info) + namelen + 1, &off_tmp);
+ if (offset) {
+ prop_info* info = new(offset) prop_info(name, namelen, value, valuelen);
*off = off_tmp;
+ return info;
}
- return info;
+ return NULL;
}
-static void *to_prop_obj(prop_off_t off)
+static void *to_prop_obj(const uint32_t off)
{
if (off > pa_data_size)
return NULL;
if (!__system_property_area__)
return NULL;
- return __system_property_area__->data + off;
+ return (__system_property_area__->data + off);
}
static prop_bt *root_node()
{
- return to_prop_obj(0);
+ return reinterpret_cast<prop_bt*>(to_prop_obj(0));
}
static int cmp_prop_name(const char *one, uint8_t one_len, const char *two,
return strncmp(one, two, one_len);
}
-static prop_bt *find_prop_bt(prop_bt *bt, const char *name, uint8_t namelen,
- bool alloc_if_needed)
+static prop_bt *find_prop_bt(prop_bt *const bt, const char *name,
+ uint8_t namelen, bool alloc_if_needed)
{
+
+ prop_bt* current = bt;
while (true) {
- int ret;
- if (!bt)
- return bt;
- ret = cmp_prop_name(name, namelen, bt->name, bt->namelen);
+ if (!current) {
+ return NULL;
+ }
+ const int ret = cmp_prop_name(name, namelen, current->name, current->namelen);
if (ret == 0) {
- return bt;
- } else if (ret < 0) {
- if (bt->left) {
- bt = to_prop_obj(bt->left);
+ return current;
+ }
+
+ if (ret < 0) {
+ if (current->left) {
+ current = reinterpret_cast<prop_bt*>(to_prop_obj(current->left));
} else {
- if (!alloc_if_needed)
+ if (!alloc_if_needed) {
return NULL;
-
- bt = new_prop_bt(name, namelen, &bt->left);
+ }
+
+ // Note that there isn't a race condition here. "clients" never
+ // reach this code-path since It's only the (single threaded) server
+ // that allocates new nodes. Though "bt->left" is volatile, it can't
+ // have changed since the last value was last read.
+ uint32_t new_offset = 0;
+ prop_bt* new_bt = new_prop_bt(name, namelen, &new_offset);
+ if (new_bt) {
+ current->left = new_offset;
+ }
+ return new_bt;
}
} else {
- if (bt->right) {
- bt = to_prop_obj(bt->right);
+ if (current->right) {
+ current = reinterpret_cast<prop_bt*>(to_prop_obj(current->right));
} else {
- if (!alloc_if_needed)
+ if (!alloc_if_needed) {
return NULL;
-
- bt = new_prop_bt(name, namelen, &bt->right);
+ }
+
+ uint32_t new_offset;
+ prop_bt* new_bt = new_prop_bt(name, namelen, &new_offset);
+ if (new_bt) {
+ current->right = new_offset;
+ }
+ return new_bt;
}
}
}
}
-static const prop_info *find_property(prop_bt *trie, const char *name,
+static const prop_info *find_property(prop_bt *const trie, const char *name,
uint8_t namelen, const char *value, uint8_t valuelen,
bool alloc_if_needed)
{
- const char *remaining_name = name;
-
if (!trie) return NULL;
+ const char *remaining_name = name;
+ prop_bt* current = trie;
while (true) {
- char *sep = strchr(remaining_name, '.');
- bool want_subtree = (sep != NULL);
- uint8_t substr_size;
+ const char *sep = strchr(remaining_name, '.');
+ const bool want_subtree = (sep != NULL);
+ const uint8_t substr_size = (want_subtree) ?
+ sep - remaining_name : strlen(remaining_name);
- prop_bt *root;
-
- if (want_subtree) {
- substr_size = sep - remaining_name;
- } else {
- substr_size = strlen(remaining_name);
- }
-
- if (!substr_size)
+ if (!substr_size) {
return NULL;
+ }
- if (trie->children) {
- root = to_prop_obj(trie->children);
+ prop_bt* root = NULL;
+ if (current->children) {
+ root = reinterpret_cast<prop_bt*>(to_prop_obj(current->children));
} else if (alloc_if_needed) {
- root = new_prop_bt(remaining_name, substr_size, &trie->children);
- } else {
- root = NULL;
+ uint32_t new_bt_offset;
+ root = new_prop_bt(remaining_name, substr_size, &new_bt_offset);
+ if (root) {
+ current->children = new_bt_offset;
+ }
}
- if (!root)
+ if (!root) {
return NULL;
+ }
- trie = find_prop_bt(root, remaining_name, substr_size, alloc_if_needed);
- if (!trie)
+ current = find_prop_bt(root, remaining_name, substr_size, alloc_if_needed);
+ if (!current) {
return NULL;
+ }
if (!want_subtree)
break;
remaining_name = sep + 1;
}
- if (trie->prop) {
- return to_prop_obj(trie->prop);
+ if (current->prop) {
+ return reinterpret_cast<prop_info*>(to_prop_obj(current->prop));
} else if (alloc_if_needed) {
- return new_prop_info(name, namelen, value, valuelen, &trie->prop);
+ uint32_t new_info_offset;
+ prop_info* new_info = new_prop_info(name, namelen, value, valuelen, &new_info_offset);
+ if (new_info) {
+ current->prop = new_info_offset;
+ }
+
+ return new_info;
} else {
return NULL;
}
}
+static int send_prop_msg(const prop_msg *msg)
+{
+ const int fd = socket(AF_LOCAL, SOCK_STREAM, 0);
+ if (fd < 0) {
+ return -1;
+ }
+
+ const size_t namelen = strlen(property_service_socket);
+
+ sockaddr_un addr;
+ memset(&addr, 0, sizeof(addr));
+ strlcpy(addr.sun_path, property_service_socket, sizeof(addr.sun_path));
+ addr.sun_family = AF_LOCAL;
+ socklen_t alen = namelen + offsetof(sockaddr_un, sun_path) + 1;
+ if (TEMP_FAILURE_RETRY(connect(fd, reinterpret_cast<sockaddr*>(&addr), alen)) < 0) {
+ close(fd);
+ return -1;
+ }
+
+ const int num_bytes = TEMP_FAILURE_RETRY(send(fd, msg, sizeof(prop_msg), 0));
+
+ int result = -1;
+ if (num_bytes == sizeof(prop_msg)) {
+ // We successfully wrote to the property server but now we
+ // wait for the property server to finish its work. It
+ // acknowledges its completion by closing the socket so we
+ // poll here (on nothing), waiting for the socket to close.
+ // If you 'adb shell setprop foo bar' you'll see the POLLHUP
+ // once the socket closes. Out of paranoia we cap our poll
+ // at 250 ms.
+ pollfd pollfds[1];
+ pollfds[0].fd = fd;
+ pollfds[0].events = 0;
+ const int poll_result = TEMP_FAILURE_RETRY(poll(pollfds, 1, 250 /* ms */));
+ if (poll_result == 1 && (pollfds[0].revents & POLLHUP) != 0) {
+ result = 0;
+ } else {
+ // Ignore the timeout and treat it like a success anyway.
+ // The init process is single-threaded and its property
+ // service is sometimes slow to respond (perhaps it's off
+ // starting a child process or something) and thus this
+ // times out and the caller thinks it failed, even though
+ // it's still getting around to it. So we fake it here,
+ // mostly for ctl.* properties, but we do try and wait 250
+ // ms so callers who do read-after-write can reliably see
+ // what they've written. Most of the time.
+ // TODO: fix the system properties design.
+ result = 0;
+ }
+ }
+
+ close(fd);
+ return result;
+}
+
+static void find_nth_fn(const prop_info *pi, void *ptr)
+{
+ find_nth_cookie *cookie = reinterpret_cast<find_nth_cookie*>(ptr);
+
+ if (cookie->n == cookie->count)
+ cookie->pi = pi;
+
+ cookie->count++;
+}
+
+static int foreach_property(const uint32_t off,
+ void (*propfn)(const prop_info *pi, void *cookie), void *cookie)
+{
+ prop_bt *trie = reinterpret_cast<prop_bt*>(to_prop_obj(off));
+ if (!trie)
+ return -1;
+
+ if (trie->left) {
+ const int err = foreach_property(trie->left, propfn, cookie);
+ if (err < 0)
+ return -1;
+ }
+ if (trie->prop) {
+ prop_info *info = reinterpret_cast<prop_info*>(to_prop_obj(trie->prop));
+ if (!info)
+ return -1;
+ propfn(info, cookie);
+ }
+ if (trie->children) {
+ const int err = foreach_property(trie->children, propfn, cookie);
+ if (err < 0)
+ return -1;
+ }
+ if (trie->right) {
+ const int err = foreach_property(trie->right, propfn, cookie);
+ if (err < 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+int __system_properties_init()
+{
+ return map_prop_area();
+}
+
+int __system_property_set_filename(const char *filename)
+{
+ size_t len = strlen(filename);
+ if (len >= sizeof(property_filename))
+ return -1;
+
+ strcpy(property_filename, filename);
+ return 0;
+}
+
+int __system_property_area_init()
+{
+ return map_prop_area_rw();
+}
+
const prop_info *__system_property_find(const char *name)
{
if (__predict_false(compat_mode)) {
{
const prop_info *pi = __system_property_find(name);
- if(pi != 0) {
+ if (pi != 0) {
return __system_property_read(pi, 0, value);
} else {
value[0] = 0;
}
}
-
-static int send_prop_msg(prop_msg *msg)
-{
- struct pollfd pollfds[1];
- struct sockaddr_un addr;
- socklen_t alen;
- size_t namelen;
- int s;
- int r;
- int result = -1;
-
- s = socket(AF_LOCAL, SOCK_STREAM, 0);
- if(s < 0) {
- return result;
- }
-
- memset(&addr, 0, sizeof(addr));
- namelen = strlen(property_service_socket);
- strlcpy(addr.sun_path, property_service_socket, sizeof addr.sun_path);
- addr.sun_family = AF_LOCAL;
- alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
-
- if(TEMP_FAILURE_RETRY(connect(s, (struct sockaddr *) &addr, alen)) < 0) {
- close(s);
- return result;
- }
-
- r = TEMP_FAILURE_RETRY(send(s, msg, sizeof(prop_msg), 0));
-
- if(r == sizeof(prop_msg)) {
- // We successfully wrote to the property server but now we
- // wait for the property server to finish its work. It
- // acknowledges its completion by closing the socket so we
- // poll here (on nothing), waiting for the socket to close.
- // If you 'adb shell setprop foo bar' you'll see the POLLHUP
- // once the socket closes. Out of paranoia we cap our poll
- // at 250 ms.
- pollfds[0].fd = s;
- pollfds[0].events = 0;
- r = TEMP_FAILURE_RETRY(poll(pollfds, 1, 250 /* ms */));
- if (r == 1 && (pollfds[0].revents & POLLHUP) != 0) {
- result = 0;
- } else {
- // Ignore the timeout and treat it like a success anyway.
- // The init process is single-threaded and its property
- // service is sometimes slow to respond (perhaps it's off
- // starting a child process or something) and thus this
- // times out and the caller thinks it failed, even though
- // it's still getting around to it. So we fake it here,
- // mostly for ctl.* properties, but we do try and wait 250
- // ms so callers who do read-after-write can reliably see
- // what they've written. Most of the time.
- // TODO: fix the system properties design.
- result = 0;
- }
- }
-
- close(s);
- return result;
-}
-
int __system_property_set(const char *key, const char *value)
{
- int err;
- prop_msg msg;
-
- if(key == 0) return -1;
- if(value == 0) value = "";
- if(strlen(key) >= PROP_NAME_MAX) return -1;
- if(strlen(value) >= PROP_VALUE_MAX) return -1;
+ if (key == 0) return -1;
+ if (value == 0) value = "";
+ if (strlen(key) >= PROP_NAME_MAX) return -1;
+ if (strlen(value) >= PROP_VALUE_MAX) return -1;
+ prop_msg msg;
memset(&msg, 0, sizeof msg);
msg.cmd = PROP_MSG_SETPROP;
strlcpy(msg.name, key, sizeof msg.name);
strlcpy(msg.value, value, sizeof msg.value);
- err = send_prop_msg(&msg);
- if(err < 0) {
+ const int err = send_prop_msg(&msg);
+ if (err < 0) {
return err;
}
int __system_property_wait(const prop_info *pi)
{
- unsigned n;
- if(pi == 0) {
+ if (pi == 0) {
prop_area *pa = __system_property_area__;
- n = pa->serial;
+ const uint32_t n = pa->serial;
do {
__futex_wait(&pa->serial, n, NULL);
- } while(n == pa->serial);
+ } while (n == pa->serial);
} else {
- n = pi->serial;
+ const uint32_t n = pi->serial;
do {
__futex_wait((volatile void *)&pi->serial, n, NULL);
} while(n == pi->serial);
return 0;
}
-
int __system_property_add(const char *name, unsigned int namelen,
const char *value, unsigned int valuelen)
{
return pa->serial;
}
-struct find_nth_cookie {
- unsigned count;
- unsigned n;
- const prop_info *pi;
-};
-
-static void find_nth_fn(const prop_info *pi, void *ptr)
-{
- struct find_nth_cookie *cookie = ptr;
-
- if (cookie->n == cookie->count)
- cookie->pi = pi;
-
- cookie->count++;
-}
-
const prop_info *__system_property_find_nth(unsigned n)
{
- struct find_nth_cookie cookie;
- int err;
+ find_nth_cookie cookie(n);
- memset(&cookie, 0, sizeof(cookie));
- cookie.n = n;
-
- err = __system_property_foreach(find_nth_fn, &cookie);
- if (err < 0)
+ const int err = __system_property_foreach(find_nth_fn, &cookie);
+ if (err < 0) {
return NULL;
-
- return cookie.pi;
-}
-
-static int foreach_property(prop_off_t off,
- void (*propfn)(const prop_info *pi, void *cookie), void *cookie)
-{
- prop_bt *trie = to_prop_obj(off);
- if (!trie)
- return -1;
-
- if (trie->left) {
- int err = foreach_property(trie->left, propfn, cookie);
- if (err < 0)
- return -1;
- }
- if (trie->prop) {
- prop_info *info = to_prop_obj(trie->prop);
- if (!info)
- return -1;
- propfn(info, cookie);
- }
- if (trie->children) {
- int err = foreach_property(trie->children, propfn, cookie);
- if (err < 0)
- return -1;
- }
- if (trie->right) {
- int err = foreach_property(trie->right, propfn, cookie);
- if (err < 0)
- return -1;
}
- return 0;
+ return cookie.pi;
}
int __system_property_foreach(void (*propfn)(const prop_info *pi, void *cookie),
{
if (__predict_false(compat_mode)) {
return __system_property_foreach_compat(propfn, cookie);
- }
+ }
+
return foreach_property(0, propfn, cookie);
}
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