Work around atomic_load(const T*) issues.
Bug:17067219
Change-Id: I78e753bcf03464f5f05c3f37e394f2727d282589
diff --git a/libc/bionic/system_properties.cpp b/libc/bionic/system_properties.cpp
index 30081a5..ad69cf5 100644
--- a/libc/bionic/system_properties.cpp
+++ b/libc/bionic/system_properties.cpp
@@ -611,6 +611,14 @@
return find_property(root_node(), name, strlen(name), NULL, 0, false);
}
+// The C11 standard doesn't allow atomic loads from const fields,
+// though C++11 does. Fudge it until standards get straightened out.
+static inline uint_least32_t load_const_atomic(const atomic_uint_least32_t* s,
+ memory_order mo) {
+ atomic_uint_least32_t* non_const_s = const_cast<atomic_uint_least32_t*>(s);
+ return atomic_load_explicit(non_const_s, mo);
+}
+
int __system_property_read(const prop_info *pi, char *name, char *value)
{
if (__predict_false(compat_mode)) {
@@ -631,7 +639,7 @@
// would be any different, so this should be OK.
atomic_thread_fence(memory_order_acquire);
if (serial ==
- atomic_load_explicit(&(pi->serial), memory_order_relaxed)) {
+ load_const_atomic(&(pi->serial), memory_order_relaxed)) {
if (name != 0) {
strcpy(name, pi->name);
}
@@ -733,12 +741,12 @@
// Wait for non-locked serial, and retrieve it with acquire semantics.
unsigned int __system_property_serial(const prop_info *pi)
{
- uint32_t serial = atomic_load_explicit(&pi->serial, memory_order_acquire);
+ uint32_t serial = load_const_atomic(&pi->serial, memory_order_acquire);
while (SERIAL_DIRTY(serial)) {
__futex_wait(const_cast<volatile void *>(
reinterpret_cast<const void *>(&pi->serial)),
serial, NULL);
- serial = atomic_load_explicit(&pi->serial, memory_order_acquire);
+ serial = load_const_atomic(&pi->serial, memory_order_acquire);
}
return serial;
}