am 072877af: am 41198eea: Merge "Revert "Rewrite atomic.h to use stdatomic.h.""

* commit '072877af485d49f11e227c0d22a7bb4a341533d6':
  Revert "Rewrite atomic.h to use stdatomic.h."

1 files changed, 145 insertions, 0 deletions

diff --git a/include/cutils/atomic-x86.h b/include/cutils/atomic-x86.h
new file mode 100644
index 0000000..06bf1a3
--- /dev/null
+++ b/include/cutils/atomic-x86.h
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_CUTILS_ATOMIC_X86_H
+#define ANDROID_CUTILS_ATOMIC_X86_H
+
+#include <stdint.h>
+
+#ifndef ANDROID_ATOMIC_INLINE
+#define ANDROID_ATOMIC_INLINE inline __attribute__((always_inline))
+#endif
+
+extern ANDROID_ATOMIC_INLINE void android_compiler_barrier(void)
+{
+    __asm__ __volatile__ ("" : : : "memory");
+}
+
+#if ANDROID_SMP == 0
+extern ANDROID_ATOMIC_INLINE void android_memory_barrier(void)
+{
+    android_compiler_barrier();
+}
+#else
+extern ANDROID_ATOMIC_INLINE void android_memory_barrier(void)
+{
+    __asm__ __volatile__ ("mfence" : : : "memory");
+}
+#endif
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_acquire_load(volatile const int32_t *ptr)
+{
+    int32_t value = *ptr;
+    android_compiler_barrier();
+    return value;
+}
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_release_load(volatile const int32_t *ptr)
+{
+    android_memory_barrier();
+    return *ptr;
+}
+
+extern ANDROID_ATOMIC_INLINE void
+android_atomic_acquire_store(int32_t value, volatile int32_t *ptr)
+{
+    *ptr = value;
+    android_memory_barrier();
+}
+
+extern ANDROID_ATOMIC_INLINE void
+android_atomic_release_store(int32_t value, volatile int32_t *ptr)
+{
+    android_compiler_barrier();
+    *ptr = value;
+}
+
+extern ANDROID_ATOMIC_INLINE int
+android_atomic_cas(int32_t old_value, int32_t new_value, volatile int32_t *ptr)
+{
+    int32_t prev;
+    __asm__ __volatile__ ("lock; cmpxchgl %1, %2"
+                          : "=a" (prev)
+                          : "q" (new_value), "m" (*ptr), "0" (old_value)
+                          : "memory");
+    return prev != old_value;
+}
+
+extern ANDROID_ATOMIC_INLINE int
+android_atomic_acquire_cas(int32_t old_value,
+                           int32_t new_value,
+                           volatile int32_t *ptr)
+{
+    /* Loads are not reordered with other loads. */
+    return android_atomic_cas(old_value, new_value, ptr);
+}
+
+extern ANDROID_ATOMIC_INLINE int
+android_atomic_release_cas(int32_t old_value,
+                           int32_t new_value,
+                           volatile int32_t *ptr)
+{
+    /* Stores are not reordered with other stores. */
+    return android_atomic_cas(old_value, new_value, ptr);
+}
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_add(int32_t increment, volatile int32_t *ptr)
+{
+    __asm__ __volatile__ ("lock; xaddl %0, %1"
+                          : "+r" (increment), "+m" (*ptr)
+                          : : "memory");
+    /* increment now holds the old value of *ptr */
+    return increment;
+}
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_inc(volatile int32_t *addr)
+{
+    return android_atomic_add(1, addr);
+}
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_dec(volatile int32_t *addr)
+{
+    return android_atomic_add(-1, addr);
+}
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_and(int32_t value, volatile int32_t *ptr)
+{
+    int32_t prev, status;
+    do {
+        prev = *ptr;
+        status = android_atomic_cas(prev, prev & value, ptr);
+    } while (__builtin_expect(status != 0, 0));
+    return prev;
+}
+
+extern ANDROID_ATOMIC_INLINE int32_t
+android_atomic_or(int32_t value, volatile int32_t *ptr)
+{
+    int32_t prev, status;
+    do {
+        prev = *ptr;
+        status = android_atomic_cas(prev, prev | value, ptr);
+    } while (__builtin_expect(status != 0, 0));
+    return prev;
+}
+
+#endif /* ANDROID_CUTILS_ATOMIC_X86_H */