Un-deprecated __system_property_find_nth.
Netflix was using this, and looking the header file, although
__system_property_find_nth has been available since the beginning of time,
__system_property_foreach only appeared in 16. So anyone who wants to run
on pre-JellyBean devices would want to use __system_property_find_nth.
It's pretty much a one-liner in terms of __system_property_foreach anyway,
so it doesn't cost us anything to keep it.
Also restore slightly better tests than we originally removed.
Bug: http://b/36566667
Test: ran tests
Change-Id: Id268c2c2e848da17bb0a5a5420af234d9dcb829a
diff --git a/libc/bionic/system_properties.cpp b/libc/bionic/system_properties.cpp
index e5947c8..9fb03ac 100644
--- a/libc/bionic/system_properties.cpp
+++ b/libc/bionic/system_properties.cpp
@@ -200,15 +200,6 @@
DISALLOW_IMPLICIT_CONSTRUCTORS(prop_info);
};
-struct find_nth_cookie {
- uint32_t count;
- const uint32_t n;
- const prop_info* pi;
-
- explicit find_nth_cookie(uint32_t n) : count(0), n(n), pi(nullptr) {
- }
-};
-
// This is public because it was exposed in the NDK. As of 2017-01, ~60 apps reference this symbol.
prop_area* __system_property_area__ = nullptr;
@@ -659,14 +650,6 @@
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++;
-}
-
bool prop_area::foreach_property(prop_bt* const trie,
void (*propfn)(const prop_info* pi, void* cookie), void* cookie) {
if (!trie) return false;
@@ -1456,20 +1439,19 @@
}
const prop_info* __system_property_find_nth(unsigned n) {
- if (bionic_get_application_target_sdk_version() >= __ANDROID_API_O__) {
- __libc_fatal(
- "__system_property_find_nth is not supported since Android O,"
- " please use __system_property_foreach instead.");
- }
+ struct find_nth {
+ const uint32_t sought;
+ uint32_t current;
+ const prop_info* result;
- find_nth_cookie cookie(n);
-
- const int err = __system_property_foreach(find_nth_fn, &cookie);
- if (err < 0) {
- return nullptr;
- }
-
- return cookie.pi;
+ explicit find_nth(uint32_t n) : sought(n), current(0), result(nullptr) {}
+ static void fn(const prop_info* pi, void* ptr) {
+ find_nth* self = reinterpret_cast<find_nth*>(ptr);
+ if (self->current++ == self->sought) self->result = pi;
+ }
+ } state(n);
+ __system_property_foreach(find_nth::fn, &state);
+ return state.result;
}
int __system_property_foreach(void (*propfn)(const prop_info* pi, void* cookie), void* cookie) {
@@ -1479,7 +1461,7 @@
list_foreach(contexts, [propfn, cookie](context_node* l) {
if (l->check_access_and_open()) {
- l->pa()->foreach (propfn, cookie);
+ l->pa()->foreach(propfn, cookie);
}
});
return 0;