vulkan: Add a dummy sync type

This is useful in WSI scenarios where you want to trivially signal a
fence or semaphore.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13427>

src/vulkan/runtime/meson.build

@@ -60,6 +60,8 @@ vulkan_runtime_files = files(
   'vk_sync.h',
   'vk_sync_binary.c',
   'vk_sync_binary.h',
+  'vk_sync_dummy.c',
+  'vk_sync_dummy.h',
   'vk_sync_timeline.c',
   'vk_sync_timeline.h',
   'vk_synchronization2.c',

src/vulkan/runtime/vk_queue.c

@@ -36,6 +36,7 @@
 #include "vk_semaphore.h"
 #include "vk_sync.h"
 #include "vk_sync_binary.h"
+#include "vk_sync_dummy.h"
 #include "vk_sync_timeline.h"
 #include "vk_util.h"
 
@@ -257,6 +258,10 @@ vk_queue_submit_final(struct vk_queue *queue,
           submit->waits[i].wait_value == 0)
          continue;
 
+      /* Waits on dummy vk_syncs are no-ops */
+      if (vk_sync_type_is_dummy(submit->waits[i].sync->type))
+         continue;
+
       /* For emulated timelines, we have a binary vk_sync associated with
        * each time point and pass the binary vk_sync to the driver.
        */

src/vulkan/runtime/vk_sync_dummy.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright © 2021 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "vk_sync_dummy.h"
+
+static VkResult
+vk_sync_dummy_init(struct vk_device *device,
+                   struct vk_sync *sync,
+                   uint64_t initial_value)
+{
+   return VK_SUCCESS;
+}
+
+static void
+vk_sync_dummy_finish(struct vk_device *device,
+                     struct vk_sync *sync)
+{ }
+
+static VkResult
+vk_sync_dummy_wait_many(struct vk_device *device,
+                        uint32_t wait_count,
+                        const struct vk_sync_wait *waits,
+                        enum vk_sync_wait_flags wait_flags,
+                        uint64_t abs_timeout_ns)
+{
+   return VK_SUCCESS;
+}
+
+const struct vk_sync_type vk_sync_dummy_type = {
+   .size = sizeof(struct vk_sync),
+   .features = VK_SYNC_FEATURE_BINARY |
+               VK_SYNC_FEATURE_GPU_WAIT |
+               VK_SYNC_FEATURE_CPU_WAIT |
+               VK_SYNC_FEATURE_WAIT_ANY |
+               VK_SYNC_FEATURE_WAIT_PENDING,
+   .init = vk_sync_dummy_init,
+   .finish = vk_sync_dummy_finish,
+   .wait_many = vk_sync_dummy_wait_many,
+};

src/vulkan/runtime/vk_sync_dummy.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright © 2021 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#ifndef VK_SYNC_DUMMY_H
+#define VK_SYNC_DUMMY_H
+
+#include "vk_sync.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const struct vk_sync_type vk_sync_dummy_type;
+
+static inline bool
+vk_sync_type_is_dummy(const struct vk_sync_type *type)
+{
+   return type == &vk_sync_dummy_type;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* VK_SYNC_H */