1 files changed, 134 insertions, 0 deletions
diff --git a/atomic/unix/builtins.c b/atomic/unix/builtins.c
new file mode 100644
index 0000000..22b828c
--- /dev/null
+++ b/atomic/unix/builtins.c
@@ -0,0 +1,134 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ */
+
+#include "apr_arch_atomic.h"
+
+#ifdef USE_ATOMICS_BUILTINS
+
+#if defined(__arm__) || defined(__powerpc__) || defined(__powerpc64__)
+#define WEAK_MEMORY_ORDERING 1
+#else
+#define WEAK_MEMORY_ORDERING 0
+#endif
+
+APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p)
+{
+    return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem)
+{
+#if HAVE__ATOMIC_BUILTINS
+    return __atomic_load_n(mem, __ATOMIC_SEQ_CST);
+#elif WEAK_MEMORY_ORDERING
+    /* No __sync_load() available => apr_atomic_add32(mem, 0) */
+    return __sync_fetch_and_add(mem, 0);
+#else
+    return *mem;
+#endif
+}
+
+APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+#if HAVE__ATOMIC_BUILTINS
+    __atomic_store_n(mem, val, __ATOMIC_SEQ_CST);
+#elif WEAK_MEMORY_ORDERING
+    /* No __sync_store() available => apr_atomic_xchg32(mem, val) */
+    __sync_synchronize();
+    __sync_lock_test_and_set(mem, val);
+#else
+    *mem = val;
+#endif
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+#if HAVE__ATOMIC_BUILTINS
+    return __atomic_fetch_add(mem, val, __ATOMIC_SEQ_CST);
+#else
+    return __sync_fetch_and_add(mem, val);
+#endif
+}
+
+APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+#if HAVE__ATOMIC_BUILTINS
+    __atomic_fetch_sub(mem, val, __ATOMIC_SEQ_CST);
+#else
+    __sync_fetch_and_sub(mem, val);
+#endif
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem)
+{
+#if HAVE__ATOMIC_BUILTINS
+    return __atomic_fetch_add(mem, 1, __ATOMIC_SEQ_CST);
+#else
+    return __sync_fetch_and_add(mem, 1);
+#endif
+}
+
+APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem)
+{
+#if HAVE__ATOMIC_BUILTINS
+    return __atomic_sub_fetch(mem, 1, __ATOMIC_SEQ_CST);
+#else
+    return __sync_sub_and_fetch(mem, 1);
+#endif
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t val,
+                                           apr_uint32_t cmp)
+{
+#if HAVE__ATOMIC_BUILTINS
+    __atomic_compare_exchange_n(mem, &cmp, val, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
+    return cmp;
+#else
+    return __sync_val_compare_and_swap(mem, cmp, val);
+#endif
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+#if HAVE__ATOMIC_BUILTINS
+    return __atomic_exchange_n(mem, val, __ATOMIC_SEQ_CST);
+#else
+    __sync_synchronize();
+    return __sync_lock_test_and_set(mem, val);
+#endif
+}
+
+APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *ptr, const void *cmp)
+{
+#if HAVE__ATOMIC_BUILTINS
+    __atomic_compare_exchange_n(mem, (void **)&cmp, ptr, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
+    return (void *)cmp;
+#else
+    return (void *)__sync_val_compare_and_swap(mem, (void *)cmp, ptr);
+#endif
+}
+
+APR_DECLARE(void*) apr_atomic_xchgptr(volatile void **mem, void *ptr)
+{
+#if HAVE__ATOMIC_BUILTINS
+    return (void *)__atomic_exchange_n(mem, ptr, __ATOMIC_SEQ_CST);
+#else
+    __sync_synchronize();
+    return (void *)__sync_lock_test_and_set(mem, ptr);
+#endif
+}
+
+#endif /* USE_ATOMICS_BUILTINS */