3 files changed, 468 insertions, 1 deletions
diff --git a/src/video_core/CMakeLists.txt b/src/video_core/CMakeLists.txt
index d35a738d5..59319f206 100644
--- a/src/video_core/CMakeLists.txt
+++ b/src/video_core/CMakeLists.txt
@@ -105,7 +105,9 @@ if (ENABLE_VULKAN)
     target_sources(video_core PRIVATE
         renderer_vulkan/declarations.h
         renderer_vulkan/vk_device.cpp
-        renderer_vulkan/vk_device.h)
+        renderer_vulkan/vk_device.h
+        renderer_vulkan/vk_resource_manager.cpp
+        renderer_vulkan/vk_resource_manager.h)
 
     target_include_directories(video_core PRIVATE ../../externals/Vulkan-Headers/include)
     target_compile_definitions(video_core PRIVATE HAS_VULKAN)
diff --git a/src/video_core/renderer_vulkan/vk_resource_manager.cpp b/src/video_core/renderer_vulkan/vk_resource_manager.cpp
new file mode 100644
index 000000000..1678463c7
--- /dev/null
+++ b/src/video_core/renderer_vulkan/vk_resource_manager.cpp
@@ -0,0 +1,285 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <optional>
+#include "common/assert.h"
+#include "common/logging/log.h"
+#include "video_core/renderer_vulkan/declarations.h"
+#include "video_core/renderer_vulkan/vk_device.h"
+#include "video_core/renderer_vulkan/vk_resource_manager.h"
+
+namespace Vulkan {
+
+// TODO(Rodrigo): Fine tune these numbers.
+constexpr std::size_t COMMAND_BUFFER_POOL_SIZE = 0x1000;
+constexpr std::size_t FENCES_GROW_STEP = 0x40;
+
+class CommandBufferPool final : public VKFencedPool {
+public:
+    CommandBufferPool(const VKDevice& device)
+        : VKFencedPool(COMMAND_BUFFER_POOL_SIZE), device{device} {}
+
+    void Allocate(std::size_t begin, std::size_t end) {
+        const auto dev = device.GetLogical();
+        const auto& dld = device.GetDispatchLoader();
+        const u32 graphics_family = device.GetGraphicsFamily();
+
+        auto pool = std::make_unique<Pool>();
+
+        // Command buffers are going to be commited, recorded, executed every single usage cycle.
+        // They are also going to be reseted when commited.
+        const auto pool_flags = vk::CommandPoolCreateFlagBits::eTransient |
+                                vk::CommandPoolCreateFlagBits::eResetCommandBuffer;
+        const vk::CommandPoolCreateInfo cmdbuf_pool_ci(pool_flags, graphics_family);
+        pool->handle = dev.createCommandPoolUnique(cmdbuf_pool_ci, nullptr, dld);
+
+        const vk::CommandBufferAllocateInfo cmdbuf_ai(*pool->handle,
+                                                      vk::CommandBufferLevel::ePrimary,
+                                                      static_cast<u32>(COMMAND_BUFFER_POOL_SIZE));
+        pool->cmdbufs =
+            dev.allocateCommandBuffersUnique<std::allocator<UniqueCommandBuffer>>(cmdbuf_ai, dld);
+
+        pools.push_back(std::move(pool));
+    }
+
+    vk::CommandBuffer Commit(VKFence& fence) {
+        const std::size_t index = CommitResource(fence);
+        const auto pool_index = index / COMMAND_BUFFER_POOL_SIZE;
+        const auto sub_index = index % COMMAND_BUFFER_POOL_SIZE;
+        return *pools[pool_index]->cmdbufs[sub_index];
+    }
+
+private:
+    struct Pool {
+        UniqueCommandPool handle;
+        std::vector<UniqueCommandBuffer> cmdbufs;
+    };
+
+    const VKDevice& device;
+
+    std::vector<std::unique_ptr<Pool>> pools;
+};
+
+VKResource::VKResource() = default;
+
+VKResource::~VKResource() = default;
+
+VKFence::VKFence(const VKDevice& device, UniqueFence handle)
+    : device{device}, handle{std::move(handle)} {}
+
+VKFence::~VKFence() = default;
+
+void VKFence::Wait() {
+    const auto dev = device.GetLogical();
+    const auto& dld = device.GetDispatchLoader();
+    dev.waitForFences({*handle}, true, std::numeric_limits<u64>::max(), dld);
+}
+
+void VKFence::Release() {
+    is_owned = false;
+}
+
+void VKFence::Commit() {
+    is_owned = true;
+    is_used = true;
+}
+
+bool VKFence::Tick(bool gpu_wait, bool owner_wait) {
+    if (!is_used) {
+        // If a fence is not used it's always free.
+        return true;
+    }
+    if (is_owned && !owner_wait) {
+        // The fence is still being owned (Release has not been called) and ownership wait has
+        // not been asked.
+        return false;
+    }
+
+    const auto dev = device.GetLogical();
+    const auto& dld = device.GetDispatchLoader();
+    if (gpu_wait) {
+        // Wait for the fence if it has been requested.
+        dev.waitForFences({*handle}, true, std::numeric_limits<u64>::max(), dld);
+    } else {
+        if (dev.getFenceStatus(*handle, dld) != vk::Result::eSuccess) {
+            // Vulkan fence is not ready, not much it can do here
+            return false;
+        }
+    }
+
+    // Broadcast resources their free state.
+    for (auto* resource : protected_resources) {
+        resource->OnFenceRemoval(this);
+    }
+    protected_resources.clear();
+
+    // Prepare fence for reusage.
+    dev.resetFences({*handle}, dld);
+    is_used = false;
+    return true;
+}
+
+void VKFence::Protect(VKResource* resource) {
+    protected_resources.push_back(resource);
+}
+
+void VKFence::Unprotect(const VKResource* resource) {
+    const auto it = std::find(protected_resources.begin(), protected_resources.end(), resource);
+    if (it != protected_resources.end()) {
+        protected_resources.erase(it);
+    }
+}
+
+VKFenceWatch::VKFenceWatch() = default;
+
+VKFenceWatch::~VKFenceWatch() {
+    if (fence) {
+        fence->Unprotect(this);
+    }
+}
+
+void VKFenceWatch::Wait() {
+    if (!fence) {
+        return;
+    }
+    fence->Wait();
+    fence->Unprotect(this);
+    fence = nullptr;
+}
+
+void VKFenceWatch::Watch(VKFence& new_fence) {
+    Wait();
+    fence = &new_fence;
+    fence->Protect(this);
+}
+
+bool VKFenceWatch::TryWatch(VKFence& new_fence) {
+    if (fence) {
+        return false;
+    }
+    fence = &new_fence;
+    fence->Protect(this);
+    return true;
+}
+
+void VKFenceWatch::OnFenceRemoval(VKFence* signaling_fence) {
+    ASSERT_MSG(signaling_fence == fence, "Removing the wrong fence");
+    fence = nullptr;
+}
+
+VKFencedPool::VKFencedPool(std::size_t grow_step) : grow_step{grow_step} {}
+
+VKFencedPool::~VKFencedPool() = default;
+
+std::size_t VKFencedPool::CommitResource(VKFence& fence) {
+    const auto Search = [&](std::size_t begin, std::size_t end) -> std::optional<std::size_t> {
+        for (std::size_t iterator = begin; iterator < end; ++iterator) {
+            if (watches[iterator]->TryWatch(fence)) {
+                // The resource is now being watched, a free resource was successfully found.
+                return iterator;
+            }
+        }
+        return {};
+    };
+    // Try to find a free resource from the hinted position to the end.
+    auto found = Search(free_iterator, watches.size());
+    if (!found) {
+        // Search from beginning to the hinted position.
+        found = Search(0, free_iterator);
+        if (!found) {
+            // Both searches failed, the pool is full; handle it.
+            const std::size_t free_resource = ManageOverflow();
+
+            // Watch will wait for the resource to be free.
+            watches[free_resource]->Watch(fence);
+            found = free_resource;
+        }
+    }
+    // Free iterator is hinted to the resource after the one that's been commited.
+    free_iterator = (*found + 1) % watches.size();
+    return *found;
+}
+
+std::size_t VKFencedPool::ManageOverflow() {
+    const std::size_t old_capacity = watches.size();
+    Grow();
+
+    // The last entry is guaranted to be free, since it's the first element of the freshly
+    // allocated resources.
+    return old_capacity;
+}
+
+void VKFencedPool::Grow() {
+    const std::size_t old_capacity = watches.size();
+    watches.resize(old_capacity + grow_step);
+    std::generate(watches.begin() + old_capacity, watches.end(),
+                  []() { return std::make_unique<VKFenceWatch>(); });
+    Allocate(old_capacity, old_capacity + grow_step);
+}
+
+VKResourceManager::VKResourceManager(const VKDevice& device) : device{device} {
+    GrowFences(FENCES_GROW_STEP);
+    command_buffer_pool = std::make_unique<CommandBufferPool>(device);
+}
+
+VKResourceManager::~VKResourceManager() = default;
+
+VKFence& VKResourceManager::CommitFence() {
+    const auto StepFences = [&](bool gpu_wait, bool owner_wait) -> VKFence* {
+        const auto Tick = [=](auto& fence) { return fence->Tick(gpu_wait, owner_wait); };
+        const auto hinted = fences.begin() + fences_iterator;
+
+        auto it = std::find_if(hinted, fences.end(), Tick);
+        if (it == fences.end()) {
+            it = std::find_if(fences.begin(), hinted, Tick);
+            if (it == hinted) {
+                return nullptr;
+            }
+        }
+        fences_iterator = std::distance(fences.begin(), it) + 1;
+        if (fences_iterator >= fences.size())
+            fences_iterator = 0;
+
+        auto& fence = *it;
+        fence->Commit();
+        return fence.get();
+    };
+
+    VKFence* found_fence = StepFences(false, false);
+    if (!found_fence) {
+        // Try again, this time waiting.
+        found_fence = StepFences(true, false);
+
+        if (!found_fence) {
+            // Allocate new fences and try again.
+            LOG_INFO(Render_Vulkan, "Allocating new fences {} -> {}", fences.size(),
+                     fences.size() + FENCES_GROW_STEP);
+
+            GrowFences(FENCES_GROW_STEP);
+            found_fence = StepFences(true, false);
+            ASSERT(found_fence != nullptr);
+        }
+    }
+    return *found_fence;
+}
+
+vk::CommandBuffer VKResourceManager::CommitCommandBuffer(VKFence& fence) {
+    return command_buffer_pool->Commit(fence);
+}
+
+void VKResourceManager::GrowFences(std::size_t new_fences_count) {
+    const auto dev = device.GetLogical();
+    const auto& dld = device.GetDispatchLoader();
+    const vk::FenceCreateInfo fence_ci;
+
+    const std::size_t previous_size = fences.size();
+    fences.resize(previous_size + new_fences_count);
+
+    std::generate(fences.begin() + previous_size, fences.end(), [&]() {
+        return std::make_unique<VKFence>(device, dev.createFenceUnique(fence_ci, nullptr, dld));
+    });
+}
+
+} // namespace Vulkan
diff --git a/src/video_core/renderer_vulkan/vk_resource_manager.h b/src/video_core/renderer_vulkan/vk_resource_manager.h
new file mode 100644
index 000000000..5018dfa44
--- /dev/null
+++ b/src/video_core/renderer_vulkan/vk_resource_manager.h
@@ -0,0 +1,180 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstddef>
+#include <memory>
+#include <vector>
+#include "video_core/renderer_vulkan/declarations.h"
+
+namespace Vulkan {
+
+class VKDevice;
+class VKFence;
+class VKResourceManager;
+
+class CommandBufferPool;
+
+/// Interface for a Vulkan resource
+class VKResource {
+public:
+    explicit VKResource();
+    virtual ~VKResource();
+
+    /**
+     * Signals the object that an owning fence has been signaled.
+     * @param signaling_fence Fence that signals its usage end.
+     */
+    virtual void OnFenceRemoval(VKFence* signaling_fence) = 0;
+};
+
+/**
+ * Fences take ownership of objects, protecting them from GPU-side or driver-side concurrent access.
+ * They must be commited from the resource manager. Their usage flow is: commit the fence from the
+ * resource manager, protect resources with it and use them, send the fence to an execution queue
+ * and Wait for it if needed and then call Release. Used resources will automatically be signaled
+ * when they are free to be reused.
+ * @brief Protects resources for concurrent usage and signals its release.
+ */
+class VKFence {
+    friend class VKResourceManager;
+
+public:
+    explicit VKFence(const VKDevice& device, UniqueFence handle);
+    ~VKFence();
+
+    /**
+     * Waits for the fence to be signaled.
+     * @warning You must have ownership of the fence and it has to be previously sent to a queue to
+     * call this function.
+     */
+    void Wait();
+
+    /**
+     * Releases ownership of the fence. Pass after it has been sent to an execution queue.
+     * Unmanaged usage of the fence after the call will result in undefined behavior because it may
+     * be being used for something else.
+     */
+    void Release();
+
+    /// Protects a resource with this fence.
+    void Protect(VKResource* resource);
+
+    /// Removes protection for a resource.
+    void Unprotect(const VKResource* resource);
+
+    /// Retreives the fence.
+    operator vk::Fence() const {
+        return *handle;
+    }
+
+private:
+    /// Take ownership of the fence.
+    void Commit();
+
+    /**
+     * Updates the fence status.
+     * @warning Waiting for the owner might soft lock the execution.
+     * @param gpu_wait Wait for the fence to be signaled by the driver.
+     * @param owner_wait Wait for the owner to signal its freedom.
+     * @returns True if the fence is free. Waiting for gpu and owner will always return true.
+     */
+    bool Tick(bool gpu_wait, bool owner_wait);
+
+    const VKDevice& device;                       ///< Device handler
+    UniqueFence handle;                           ///< Vulkan fence
+    std::vector<VKResource*> protected_resources; ///< List of resources protected by this fence
+    bool is_owned = false; ///< The fence has been commited but not released yet.
+    bool is_used = false;  ///< The fence has been commited but it has not been checked to be free.
+};
+
+/**
+ * A fence watch is used to keep track of the usage of a fence and protect a resource or set of
+ * resources without having to inherit VKResource from their handlers.
+ */
+class VKFenceWatch final : public VKResource {
+public:
+    explicit VKFenceWatch();
+    ~VKFenceWatch();
+
+    /// Waits for the fence to be released.
+    void Wait();
+
+    /**
+     * Waits for a previous fence and watches a new one.
+     * @param new_fence New fence to wait to.
+     */
+    void Watch(VKFence& new_fence);
+
+    /**
+     * Checks if it's currently being watched and starts watching it if it's available.
+     * @returns True if a watch has started, false if it's being watched.
+     */
+    bool TryWatch(VKFence& new_fence);
+
+    void OnFenceRemoval(VKFence* signaling_fence) override;
+
+private:
+    VKFence* fence{}; ///< Fence watching this resource. nullptr when the watch is free.
+};
+
+/**
+ * Handles a pool of resources protected by fences. Manages resource overflow allocating more
+ * resources.
+ */
+class VKFencedPool {
+public:
+    explicit VKFencedPool(std::size_t grow_step);
+    virtual ~VKFencedPool();
+
+protected:
+    /**
+     * Commits a free resource and protects it with a fence. It may allocate new resources.
+     * @param fence Fence that protects the commited resource.
+     * @returns Index of the resource commited.
+     */
+    std::size_t CommitResource(VKFence& fence);
+
+    /// Called when a chunk of resources have to be allocated.
+    virtual void Allocate(std::size_t begin, std::size_t end) = 0;
+
+private:
+    /// Manages pool overflow allocating new resources.
+    std::size_t ManageOverflow();
+
+    /// Allocates a new page of resources.
+    void Grow();
+
+    std::size_t grow_step = 0;     ///< Number of new resources created after an overflow
+    std::size_t free_iterator = 0; ///< Hint to where the next free resources is likely to be found
+    std::vector<std::unique_ptr<VKFenceWatch>> watches; ///< Set of watched resources
+};
+
+/**
+ * The resource manager handles all resources that can be protected with a fence avoiding
+ * driver-side or GPU-side concurrent usage. Usage is documented in VKFence.
+ */
+class VKResourceManager final {
+public:
+    explicit VKResourceManager(const VKDevice& device);
+    ~VKResourceManager();
+
+    /// Commits a fence. It has to be sent to a queue and released.
+    VKFence& CommitFence();
+
+    /// Commits an unused command buffer and protects it with a fence.
+    vk::CommandBuffer CommitCommandBuffer(VKFence& fence);
+
+private:
+    /// Allocates new fences.
+    void GrowFences(std::size_t new_fences_count);
+
+    const VKDevice& device;          ///< Device handler.
+    std::size_t fences_iterator = 0; ///< Index where a free fence is likely to be found.
+    std::vector<std::unique_ptr<VKFence>> fences;           ///< Pool of fences.
+    std::unique_ptr<CommandBufferPool> command_buffer_pool; ///< Pool of command buffers.
+};
+
+} // namespace Vulkan