examples: Resolve VUID-vkQueueSubmit-pSignalSemaphores-00067

https://docs.vulkan.org/guide/latest/swapchain_semaphore_reuse.html

A unique semaphore should be used per swapchain image, because the
presentation engine may still reference and use it before the image
index it was used with is returned out of `acquire_next_image()` again.

Alternatives include waiting for the `Fence` from
presentation in `VkSwapchainPresentFenceInfoKHR`, added by the
`VK_EXT_swapchain_maintenance1`/`VK_KHR_swapchain_maintenance1`
extension but this is less performant than just using a unique semaphore
per swapchain image.

Author: MarijnS95

ash-examples/src/bin/texture.rs

@@ -711,6 +711,9 @@ fn main() -> Result<(), Box<dyn Error>> {
                 },
             ];
 
+            let rendering_complete_semaphore =
+                base.rendering_complete_semaphores[present_index as usize];
+
             let render_pass_begin_info = vk::RenderPassBeginInfo::default()
                 .render_pass(renderpass)
                 .framebuffer(framebuffers[present_index as usize])
@@ -724,7 +727,7 @@ fn main() -> Result<(), Box<dyn Error>> {
                 base.present_queue,
                 &[vk::PipelineStageFlags::BOTTOM_OF_PIPE],
                 &[base.present_complete_semaphore],
-                &[base.rendering_complete_semaphore],
+                &[rendering_complete_semaphore],
                 |device, draw_command_buffer| {
                     device.cmd_begin_render_pass(
                         draw_command_buffer,
@@ -773,7 +776,7 @@ fn main() -> Result<(), Box<dyn Error>> {
             );
             let present_info = vk::PresentInfoKHR {
                 wait_semaphore_count: 1,
-                p_wait_semaphores: &base.rendering_complete_semaphore,
+                p_wait_semaphores: &rendering_complete_semaphore,
                 swapchain_count: 1,
                 p_swapchains: &base.swapchain,
                 p_image_indices: &present_index,

ash-examples/src/bin/triangle.rs

@@ -373,6 +373,9 @@ fn main() -> Result<(), Box<dyn Error>> {
                 },
             ];
 
+            let rendering_complete_semaphore =
+                base.rendering_complete_semaphores[present_index as usize];
+
             let render_pass_begin_info = vk::RenderPassBeginInfo::default()
                 .render_pass(renderpass)
                 .framebuffer(framebuffers[present_index as usize])
@@ -386,7 +389,7 @@ fn main() -> Result<(), Box<dyn Error>> {
                 base.present_queue,
                 &[vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT],
                 &[base.present_complete_semaphore],
-                &[base.rendering_complete_semaphore],
+                &[rendering_complete_semaphore],
                 |device, draw_command_buffer| {
                     device.cmd_begin_render_pass(
                         draw_command_buffer,
@@ -425,7 +428,7 @@ fn main() -> Result<(), Box<dyn Error>> {
                     device.cmd_end_render_pass(draw_command_buffer);
                 },
             );
-            let wait_semaphors = [base.rendering_complete_semaphore];
+            let wait_semaphors = [rendering_complete_semaphore];
             let swapchains = [base.swapchain];
             let image_indices = [present_index];
             let present_info = vk::PresentInfoKHR::default()

ash-examples/src/lib.rs

@@ -167,7 +167,7 @@ pub struct ExampleBase {
     pub depth_image_memory: vk::DeviceMemory,
 
     pub present_complete_semaphore: vk::Semaphore,
-    pub rendering_complete_semaphore: vk::Semaphore,
+    pub rendering_complete_semaphores: Vec<vk::Semaphore>,
 
     pub draw_commands_reuse_fence: vk::Fence,
     pub setup_commands_reuse_fence: vk::Fence,
@@ -533,9 +533,13 @@ impl ExampleBase {
             let present_complete_semaphore = device
                 .create_semaphore(&semaphore_create_info, None)
                 .unwrap();
-            let rendering_complete_semaphore = device
-                .create_semaphore(&semaphore_create_info, None)
-                .unwrap();
+            let rendering_complete_semaphores = (0..present_images.len())
+                .map(|_| {
+                    device
+                        .create_semaphore(&semaphore_create_info, None)
+                        .unwrap()
+                })
+                .collect();
 
             Ok(Self {
                 event_loop: RefCell::new(event_loop),
@@ -560,7 +564,7 @@ impl ExampleBase {
                 depth_image,
                 depth_image_view,
                 present_complete_semaphore,
-                rendering_complete_semaphore,
+                rendering_complete_semaphores,
                 draw_commands_reuse_fence,
                 setup_commands_reuse_fence,
                 surface,
@@ -578,16 +582,17 @@ impl Drop for ExampleBase {
             self.device.device_wait_idle().unwrap();
             self.device
                 .destroy_semaphore(self.present_complete_semaphore, None);
-            self.device
-                .destroy_semaphore(self.rendering_complete_semaphore, None);
+            for &semaphore in &self.rendering_complete_semaphores {
+                self.device.destroy_semaphore(semaphore, None);
+            }
             self.device
                 .destroy_fence(self.draw_commands_reuse_fence, None);
             self.device
                 .destroy_fence(self.setup_commands_reuse_fence, None);
             self.device.free_memory(self.depth_image_memory, None);
             self.device.destroy_image_view(self.depth_image_view, None);
             self.device.destroy_image(self.depth_image, None);
-            for &image_view in self.present_image_views.iter() {
+            for &image_view in &self.present_image_views {
                 self.device.destroy_image_view(image_view, None);
             }
             self.device.destroy_command_pool(self.pool, None);