Merge "Fix, generalize stdatomic.h; improve test."
diff --git a/libc/include/stdatomic.h b/libc/include/stdatomic.h
index 2c04221..adf60bb 100644
--- a/libc/include/stdatomic.h
+++ b/libc/include/stdatomic.h
@@ -123,6 +123,12 @@
* bits as a T.
*/
+#include <stddef.h> /* For ptrdiff_t. */
+#include <stdint.h> /* TODO: Should pollute namespace less. */
+#if __STDC_VERSION__ >= 201112L
+# include <uchar.h> /* For char16_t and char32_t. */
+#endif
+
#if __has_extension(c_atomic) || __has_extension(cxx_atomic)
#define __CLANG_ATOMICS
#elif __GNUC_PREREQ__(4, 7)
@@ -228,7 +234,7 @@
*/
static __inline void
-atomic_thread_fence(memory_order __order __unused)
+atomic_thread_fence(memory_order __order __attribute__((unused)))
{
#ifdef __CLANG_ATOMICS
@@ -241,7 +247,7 @@
}
static __inline void
-atomic_signal_fence(memory_order __order __unused)
+atomic_signal_fence(memory_order __order __attribute__((unused)))
{
#ifdef __CLANG_ATOMICS
@@ -263,7 +269,7 @@
((void)(obj), (_Bool)1)
#elif defined(__CLANG_ATOMICS)
#define atomic_is_lock_free(obj) \
- __atomic_is_lock_free(sizeof(*(obj)), obj)
+ __c11_atomic_is_lock_free(sizeof(*(obj)))
#elif defined(__GNUC_ATOMICS)
#define atomic_is_lock_free(obj) \
__atomic_is_lock_free(sizeof((obj)->__val), &(obj)->__val)
@@ -477,7 +483,7 @@
atomic_bool __flag;
} atomic_flag;
-#define ATOMIC_FLAG_INIT { ATOMIC_VAR_INIT(0) }
+#define ATOMIC_FLAG_INIT { ATOMIC_VAR_INIT(false) }
static __inline bool
atomic_flag_test_and_set_explicit(volatile atomic_flag *__object,
diff --git a/tests/Android.mk b/tests/Android.mk
index 4f1661a..13d7cbe 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -239,7 +239,8 @@
# -----------------------------------------------------------------------------
# Tests for the device using bionic's .so. Run with:
-# adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests
+# adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests32
+# adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests64
# -----------------------------------------------------------------------------
bionic-unit-tests_whole_static_libraries := \
libBionicTests \
@@ -275,7 +276,8 @@
# -----------------------------------------------------------------------------
# Tests for the device linked against bionic's static library. Run with:
-# adb shell /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static
+# adb shell /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static32
+# adb shell /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static64
# -----------------------------------------------------------------------------
bionic-unit-tests-static_whole_static_libraries := \
libBionicTests \
diff --git a/tests/stdatomic_test.cpp b/tests/stdatomic_test.cpp
index 5e88c88..222bd9c 100644
--- a/tests/stdatomic_test.cpp
+++ b/tests/stdatomic_test.cpp
@@ -14,11 +14,10 @@
* limitations under the License.
*/
-#include <gtest/gtest.h>
-
-#if !defined(__GLIBC__) /* TODO: fix our prebuilt toolchains! */
-
#include <stdatomic.h>
+#include <gtest/gtest.h>
+#include <pthread.h>
+#include <stdint.h>
TEST(stdatomic, LOCK_FREE) {
ASSERT_TRUE(ATOMIC_BOOL_LOCK_FREE);
@@ -167,4 +166,80 @@
ASSERT_EQ(0x002, atomic_load(&i));
}
-#endif
+// And a rudimentary test of acquire-release memory ordering:
+
+constexpr static uint_least32_t BIG = 10000000ul; // Assumed even below.
+
+struct three_atomics {
+ atomic_uint_least32_t x;
+ char a[123]; // Everything in different cache lines,
+ // increase chance of compiler getting alignment wrong.
+ atomic_uint_least32_t y;
+ char b[4013];
+ atomic_uint_least32_t z;
+};
+
+// Very simple acquire/release memory ordering sanity check.
+static void* writer(void* arg) {
+ three_atomics* a = reinterpret_cast<three_atomics*>(arg);
+ for (uint_least32_t i = 0; i <= BIG; i+=2) {
+ atomic_store_explicit(&a->x, i, memory_order_relaxed);
+ atomic_store_explicit(&a->z, i, memory_order_relaxed);
+ atomic_store_explicit(&a->y, i, memory_order_release);
+ atomic_store_explicit(&a->x, i+1, memory_order_relaxed);
+ atomic_store_explicit(&a->z, i+1, memory_order_relaxed);
+ atomic_store_explicit(&a->y, i+1, memory_order_release);
+ }
+ return 0;
+}
+
+static void* reader(void* arg) {
+ three_atomics* a = reinterpret_cast<three_atomics*>(arg);
+ uint_least32_t xval = 0, yval = 0, zval = 0;
+ size_t repeat = 0;
+ size_t repeat_limit = 1000;
+ while (yval != BIG + 1) {
+ yval = atomic_load_explicit(&a->y, memory_order_acquire);
+ zval = atomic_load_explicit(&a->z, memory_order_relaxed);
+ xval = atomic_load_explicit(&a->x, memory_order_relaxed);
+ // If we see a given value of y, the immediately preceding
+ // stores to z and x, or later ones, should also be visible.
+ if (zval < yval) {
+ // Cant just ASSERT, since we are in a non-void function.
+ ADD_FAILURE() << "acquire-release ordering violation: "
+ << zval << " < " << yval << ", " << xval << "\n";
+ return 0; // Only report once.
+ }
+ if (xval < yval) {
+ // Cant just ASSERT, since we are in a non-void function.
+ ADD_FAILURE() << "acquire-release ordering violation: "
+ << xval << " < " << yval << ", " << zval << "\n";
+ return 0; // Only report once.
+ }
+ if (repeat < repeat_limit) ++repeat;
+ }
+ // The following assertion is not technically guaranteed to hold.
+ // But if it fails to hold, this test was useless, and we have a
+ // serious scheduling issue that we should probably know about.
+ EXPECT_EQ(repeat, repeat_limit);
+ return 0;
+}
+
+TEST(stdatomic, ordering) {
+ // Run a memory ordering sanity test.
+ void* result;
+ three_atomics a;
+ atomic_init(&a.x, 0ul);
+ atomic_init(&a.y, 0ul);
+ atomic_init(&a.z, 0ul);
+ pthread_t t1,t2;
+ ASSERT_EQ(0, pthread_create(&t1, 0, reader, &a));
+ ASSERT_EQ(0, pthread_create(&t2, 0, writer, &a));
+ ASSERT_EQ(0, pthread_join(t1, &result));
+ EXPECT_EQ(0, result);
+ ASSERT_EQ(0, pthread_join(t2, &result));
+ EXPECT_EQ(0, result);
+ EXPECT_EQ(atomic_load_explicit(&a.x, memory_order_consume), BIG + 1);
+ EXPECT_EQ(atomic_load_explicit(&a.y, memory_order_seq_cst), BIG + 1);
+ EXPECT_EQ(atomic_load(&a.z), BIG + 1);
+}