From 5bf1114fe795ba8be9cd88f5f4af9339dd58cd90 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Sat, 4 Mar 2017 18:28:12 +0100
Subject: [PATCH] Implement GPU locks for attachment and storage images

---
 vulkano/src/image/attachment.rs | 20 +++++++++++++++++---
 vulkano/src/image/storage.rs    | 19 ++++++++++++++++---
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/vulkano/src/image/attachment.rs b/vulkano/src/image/attachment.rs
index c0b02619..0f8bc3f6 100644
--- a/vulkano/src/image/attachment.rs
+++ b/vulkano/src/image/attachment.rs
@@ -9,6 +9,8 @@
 
 use std::iter::Empty;
 use std::sync::Arc;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
 
 use device::Device;
 use device::Queue;
@@ -79,6 +81,9 @@ pub struct AttachmentImage<F, A = Arc<StdMemoryPool>> where A: MemoryPool {
     // Layout to use when the image is used as a framebuffer attachment.
     // Must be either "depth-stencil optimal" or "color optimal".
     attachment_layout: Layout,
+
+    // Number of times this image is locked on the GPU side.
+    gpu_lock: AtomicUsize,
 }
 
 impl<F> AttachmentImage<F> {
@@ -168,6 +173,7 @@ impl<F> AttachmentImage<F> {
             format: format,
             attachment_layout: if is_depth { Layout::DepthStencilAttachmentOptimal }
                                else { Layout::ColorAttachmentOptimal },
+            gpu_lock: AtomicUsize::new(0),
         }))
     }
 }
@@ -193,13 +199,20 @@ unsafe impl<F, A> Image for AttachmentImage<F, A> where F: 'static + Send + Sync
     }
 
     #[inline]
-    fn try_gpu_lock(&self, exclusive_access: bool, queue: &Queue) -> bool {
-        false       // FIXME:
+    fn try_gpu_lock(&self, _: bool, _: &Queue) -> bool {
+        let val = self.gpu_lock.fetch_add(1, Ordering::SeqCst);
+        if val == 1 {
+            true
+        } else {
+            self.gpu_lock.fetch_sub(1, Ordering::SeqCst);
+            false
+        }
     }
 
     #[inline]
     unsafe fn increase_gpu_lock(&self) {
-        // FIXME:
+        let val = self.gpu_lock.fetch_add(1, Ordering::SeqCst);
+        debug_assert!(val >= 1);
     }
 }
 
@@ -270,6 +283,7 @@ unsafe impl<F, A> ImageView for AttachmentImage<F, A>
 mod tests {
     use super::AttachmentImage;
     use format::Format;
+    use image::Image;
 
     #[test]
     fn create_regular() {
diff --git a/vulkano/src/image/storage.rs b/vulkano/src/image/storage.rs
index 41b661e8..6a1b2fe2 100644
--- a/vulkano/src/image/storage.rs
+++ b/vulkano/src/image/storage.rs
@@ -9,6 +9,8 @@
 
 use std::iter::Empty;
 use std::sync::Arc;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
 use smallvec::SmallVec;
 
 use device::Device;
@@ -54,6 +56,9 @@ pub struct StorageImage<F, A = Arc<StdMemoryPool>> where A: MemoryPool {
 
     // Queue families allowed to access this image.
     queue_families: SmallVec<[u32; 4]>,
+
+    // Number of times this image is locked on the GPU side.
+    gpu_lock: AtomicUsize,
 }
 
 impl<F> StorageImage<F> {
@@ -122,6 +127,7 @@ impl<F> StorageImage<F> {
             dimensions: dimensions,
             format: format,
             queue_families: queue_families,
+            gpu_lock: AtomicUsize::new(0),
         }))
     }
 }
@@ -146,13 +152,20 @@ unsafe impl<F, A> Image for StorageImage<F, A> where F: 'static + Send + Sync, A
     }
 
     #[inline]
-    fn try_gpu_lock(&self, exclusive_access: bool, queue: &Queue) -> bool {
-        false       // FIXME:
+    fn try_gpu_lock(&self, _: bool, _: &Queue) -> bool {
+        let val = self.gpu_lock.fetch_add(1, Ordering::SeqCst);
+        if val == 1 {
+            true
+        } else {
+            self.gpu_lock.fetch_sub(1, Ordering::SeqCst);
+            false
+        }
     }
 
     #[inline]
     unsafe fn increase_gpu_lock(&self) {
-        // FIXME:
+        let val = self.gpu_lock.fetch_add(1, Ordering::SeqCst);
+        debug_assert!(val >= 1);
     }
 }