An implementation compatible with MSVC is provided for
atomic128_cmp_exchange in rte_stack_lf_c11.h.
Now that the issues preventing the code needed to build lib/stack
have been addressed, it can be enabled so that it also gets built
when using the MSVC compiler.
Signed-off-by: Andre Muezerie <andre...@linux.microsoft.com>
---
lib/stack/meson.build | 6 ------
lib/stack/rte_stack_lf_c11.h | 27 +++++++++++++++++++++++++++
2 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/lib/stack/meson.build b/lib/stack/meson.build
index 7631a14784..18177a742f 100644
--- a/lib/stack/meson.build
+++ b/lib/stack/meson.build
@@ -1,12 +1,6 @@
# SPDX-License-Identifier: BSD-3-Clause
# Copyright(c) 2019 Intel Corporation
-if is_ms_compiler
- build = false
- reason = 'not supported building with Visual Studio Toolset'
- subdir_done()
-endif
-
sources = files('rte_stack.c', 'rte_stack_std.c', 'rte_stack_lf.c')
headers = files('rte_stack.h')
# subheaders, not for direct inclusion by apps
diff --git a/lib/stack/rte_stack_lf_c11.h b/lib/stack/rte_stack_lf_c11.h
index 60d46e963b..898d43edb2 100644
--- a/lib/stack/rte_stack_lf_c11.h
+++ b/lib/stack/rte_stack_lf_c11.h
@@ -8,6 +8,33 @@
#include <rte_branch_prediction.h>
#include <rte_prefetch.h>
+#ifdef RTE_TOOLCHAIN_MSVC
+/**
+ * The maximum lock-free data size that can be manipulated atomically using C11
+ * standard is limited to 8 bytes.
+ *
+ * This implementation for rte_atomic128_cmp_exchange operates on 16-byte
+ * data types and is made available here so that it can be used without the
+ * need to unnecessarily expose other non-C11 atomics present in
+ * rte_atomic_64.h when using MSVC.
+ */
+static inline int
+rte_atomic128_cmp_exchange(rte_int128_t *dst,
+ rte_int128_t *exp,
+ const rte_int128_t *src,
+ unsigned int weak,
+ int success,
+ int failure)
+{
+ return (int)_InterlockedCompareExchange128(
+ (int64_t volatile *) dst,
+ src->val[1], /* exchange high */
+ src->val[0], /* exchange low */
+ (int64_t *) exp /* comparand result */
+ );
+}
+#endif /* RTE_TOOLCHAIN_MSVC */
+
static __rte_always_inline unsigned int
__rte_stack_lf_count(struct rte_stack *s)
{
--
2.47.2.vfs.0.1
