From 67cd0c44d23ec8d6b907f3b4966e488e2da09475 Mon Sep 17 00:00:00 2001
From: Yonggang Luo <luoyonggang@gmail.com>
Date: Sat, 18 Jun 2022 23:55:49 +0800
Subject: [PATCH] util: Add api util_call_once_with_context

This is used to remove the need of _MTX_INITIALIZER_NP in simple_mtx.h

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17122>
---
 src/util/meson.build   |  2 ++
 src/util/u_call_once.c | 28 ++++++++++++++++++++++++++++
 src/util/u_call_once.h | 27 +++++++++++++++++++++++++++
 3 files changed, 57 insertions(+)
 create mode 100644 src/util/u_call_once.c
 create mode 100644 src/util/u_call_once.h

diff --git a/src/util/meson.build b/src/util/meson.build
index 72652d04c66..4b73ef029c1 100644
--- a/src/util/meson.build
+++ b/src/util/meson.build
@@ -118,6 +118,8 @@ files_mesa_util = files(
   'timespec.h',
   'u_atomic.c',
   'u_atomic.h',
+  'u_call_once.c',
+  'u_call_once.h',
   'u_debug_describe.c',
   'u_debug_describe.h',
   'u_debug_refcnt.c',
diff --git a/src/util/u_call_once.c b/src/util/u_call_once.c
new file mode 100644
index 00000000000..a727a02f8b9
--- /dev/null
+++ b/src/util/u_call_once.c
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2022 Yonggang Luo
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "u_call_once.h"
+
+struct util_call_once_context_t
+{
+   void *context;
+   util_call_once_callback_t callback;
+};
+
+static thread_local struct util_call_once_context_t call_once_context;
+
+static void util_call_once_with_context_callback(void)
+{
+   struct util_call_once_context_t *once_context = &call_once_context;
+   once_context->callback(once_context->context);
+}
+
+void util_call_once_with_context(once_flag *once, void *context, util_call_once_callback_t callback)
+{
+   struct util_call_once_context_t *once_context = &call_once_context;
+   once_context->context = context;
+   once_context->callback = callback;
+   call_once(once, util_call_once_with_context_callback);
+}
diff --git a/src/util/u_call_once.h b/src/util/u_call_once.h
new file mode 100644
index 00000000000..277ff721f32
--- /dev/null
+++ b/src/util/u_call_once.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2022 Yonggang Luo
+ * SPDX-License-Identifier: MIT
+ *
+ * Extend C11 call_once to support context parameter
+ */
+
+#ifndef U_CALL_ONCE_H_
+#define U_CALL_ONCE_H_
+
+#include <stdbool.h>
+
+#include "c11/threads.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (*util_call_once_callback_t)(void *context);
+
+void util_call_once_with_context(once_flag *once, void *context, util_call_once_callback_t callback);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* U_CALL_ONCE_H_ */