Emulate posix atomics for systems that do not have gnu builtins

This is probably not very fast but if the compiler doesn't support the
gnu builtins, then speed is probably not a priority.

flecs.c

@@ -19464,6 +19464,13 @@ void ecs_set_os_api_impl(void) {
 #include <time.h>
 #endif
 
+/* This mutex is used to emulate atomic operations when the gnu builtins are
+ * not supported. This is probably not very fast but if the compiler doesn't
+ * support the gnu built-ins, then speed is probably not a priority. */
+#ifndef __GNUC__
+static pthread_mutex_t atomic_mutex = PTHREAD_MUTEX_INITIALIZER;
+#endif
+
 static
 ecs_os_thread_t posix_thread_new(
     ecs_os_thread_callback_t callback, 
@@ -19504,8 +19511,14 @@ int32_t posix_ainc(
     value = __sync_add_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) += 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 
@@ -19518,8 +19531,14 @@ int32_t posix_adec(
     value = __sync_sub_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) -= 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 
@@ -19532,8 +19551,14 @@ int64_t posix_lainc(
     value = __sync_add_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) += 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 
@@ -19546,8 +19571,14 @@ int64_t posix_ladec(
     value = __sync_sub_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) -= 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 

src/addons/os_api_impl/posix_impl.inl

@@ -13,6 +13,13 @@
 #include <time.h>
 #endif
 
+/* This mutex is used to emulate atomic operations when the gnu builtins are
+ * not supported. This is probably not very fast but if the compiler doesn't
+ * support the gnu built-ins, then speed is probably not a priority. */
+#ifndef __GNUC__
+static pthread_mutex_t atomic_mutex = PTHREAD_MUTEX_INITIALIZER;
+#endif
+
 static
 ecs_os_thread_t posix_thread_new(
     ecs_os_thread_callback_t callback, 
@@ -53,8 +60,14 @@ int32_t posix_ainc(
     value = __sync_add_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) += 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 
@@ -67,8 +80,14 @@ int32_t posix_adec(
     value = __sync_sub_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) -= 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 
@@ -81,8 +100,14 @@ int64_t posix_lainc(
     value = __sync_add_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) += 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }
 
@@ -95,8 +120,14 @@ int64_t posix_ladec(
     value = __sync_sub_and_fetch (count, 1);
     return value;
 #else
-    /* Unsupported */
-    abort();
+    if (pthread_mutex_lock(&atomic_mutex)) {
+	    abort();
+    }
+    value = (*count) -= 1;
+    if (pthread_mutex_unlock(&atomic_mutex)) {
+	    abort();
+    }
+    return value;
 #endif
 }