vk_resource_pool: Load GPU tick once and compare with it

Other minor style improvements. Rename free_iterator to hint_iterator,
to describe better what it does.

src/video_core/renderer_vulkan/vk_resource_pool.cpp

@@ -17,21 +17,21 @@ ResourcePool::~ResourcePool() = default;
 size_t ResourcePool::CommitResource() {
     // Refresh semaphore to query updated results
     master_semaphore.Refresh();
-
+    const u64 gpu_tick = master_semaphore.KnownGpuTick();
-    const auto search = [this](size_t begin, size_t end) -> std::optional<size_t> {
+    const auto search = [this, gpu_tick](size_t begin, size_t end) -> std::optional<size_t> {
         for (size_t iterator = begin; iterator < end; ++iterator) {
-            if (master_semaphore.IsFree(ticks[iterator])) {
+            if (gpu_tick >= ticks[iterator]) {
                 ticks[iterator] = master_semaphore.CurrentTick();
                 return iterator;
             }
         }
-        return {};
+        return std::nullopt;
     };
     // Try to find a free resource from the hinted position to the end.
-    auto found = search(free_iterator, ticks.size());
+    std::optional<size_t> found = search(hint_iterator, ticks.size());
     if (!found) {
         // Search from beginning to the hinted position.
-        found = search(0, free_iterator);
+        found = search(0, hint_iterator);
         if (!found) {
             // Both searches failed, the pool is full; handle it.
             const size_t free_resource = ManageOverflow();
@@ -41,7 +41,7 @@ size_t ResourcePool::CommitResource() {
         }
     }
     // Free iterator is hinted to the resource after the one that's been commited.
-    free_iterator = (*found + 1) % ticks.size();
+    hint_iterator = (*found + 1) % ticks.size();
     return *found;
 }
 

src/video_core/renderer_vulkan/vk_resource_pool.h

@@ -36,7 +36,7 @@ private:
 
     MasterSemaphore& master_semaphore;
     size_t grow_step = 0;     ///< Number of new resources created after an overflow
-    size_t free_iterator = 0; ///< Hint to where the next free resources is likely to be found
+    size_t hint_iterator = 0; ///< Hint to where the next free resources is likely to be found
     std::vector<u64> ticks;   ///< Ticks for each resource
 };