1 files changed, 328 insertions, 0 deletions
diff --git a/Source/Core/VideoBackends/Vulkan/VKStreamBuffer.cpp b/Source/Core/VideoBackends/Vulkan/VKStreamBuffer.cpp
new file mode 100644
index 0000000000..864fabf831
--- /dev/null
+++ b/Source/Core/VideoBackends/Vulkan/VKStreamBuffer.cpp
@@ -0,0 +1,328 @@
+// Copyright 2016 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "VideoBackends/Vulkan/VKStreamBuffer.h"
+
+#include <algorithm>
+#include <cstdint>
+#include <functional>
+
+#include "Common/Align.h"
+#include "Common/Assert.h"
+#include "Common/MsgHandler.h"
+
+#include "VideoBackends/Vulkan/CommandBufferManager.h"
+#include "VideoBackends/Vulkan/VulkanContext.h"
+
+namespace Vulkan
+{
+StreamBuffer::StreamBuffer(VkBufferUsageFlags usage, u32 size) : m_usage(usage), m_size(size)
+{
+}
+
+StreamBuffer::~StreamBuffer()
+{
+  if (m_host_pointer)
+    vkUnmapMemory(g_vulkan_context->GetDevice(), m_memory);
+
+  if (m_buffer != VK_NULL_HANDLE)
+    g_command_buffer_mgr->DeferBufferDestruction(m_buffer);
+  if (m_memory != VK_NULL_HANDLE)
+    g_command_buffer_mgr->DeferDeviceMemoryDestruction(m_memory);
+}
+
+std::unique_ptr<StreamBuffer> StreamBuffer::Create(VkBufferUsageFlags usage, u32 size)
+{
+  std::unique_ptr<StreamBuffer> buffer = std::make_unique<StreamBuffer>(usage, size);
+  if (!buffer->AllocateBuffer())
+    return nullptr;
+
+  return buffer;
+}
+
+bool StreamBuffer::AllocateBuffer()
+{
+  // Create the buffer descriptor
+  VkBufferCreateInfo buffer_create_info = {
+      VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,  // VkStructureType        sType
+      nullptr,                               // const void*            pNext
+      0,                                     // VkBufferCreateFlags    flags
+      static_cast<VkDeviceSize>(m_size),     // VkDeviceSize           size
+      m_usage,                               // VkBufferUsageFlags     usage
+      VK_SHARING_MODE_EXCLUSIVE,             // VkSharingMode          sharingMode
+      0,                                     // uint32_t               queueFamilyIndexCount
+      nullptr                                // const uint32_t*        pQueueFamilyIndices
+  };
+
+  VkBuffer buffer = VK_NULL_HANDLE;
+  VkResult res =
+      vkCreateBuffer(g_vulkan_context->GetDevice(), &buffer_create_info, nullptr, &buffer);
+  if (res != VK_SUCCESS)
+  {
+    LOG_VULKAN_ERROR(res, "vkCreateBuffer failed: ");
+    return false;
+  }
+
+  // Get memory requirements (types etc) for this buffer
+  VkMemoryRequirements memory_requirements;
+  vkGetBufferMemoryRequirements(g_vulkan_context->GetDevice(), buffer, &memory_requirements);
+
+  // Aim for a coherent mapping if possible.
+  u32 memory_type_index = g_vulkan_context->GetUploadMemoryType(memory_requirements.memoryTypeBits,
+                                                                &m_coherent_mapping);
+
+  // Allocate memory for backing this buffer
+  VkMemoryAllocateInfo memory_allocate_info = {
+      VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,  // VkStructureType    sType
+      nullptr,                                 // const void*        pNext
+      memory_requirements.size,                // VkDeviceSize       allocationSize
+      memory_type_index                        // uint32_t           memoryTypeIndex
+  };
+  VkDeviceMemory memory = VK_NULL_HANDLE;
+  res = vkAllocateMemory(g_vulkan_context->GetDevice(), &memory_allocate_info, nullptr, &memory);
+  if (res != VK_SUCCESS)
+  {
+    LOG_VULKAN_ERROR(res, "vkAllocateMemory failed: ");
+    vkDestroyBuffer(g_vulkan_context->GetDevice(), buffer, nullptr);
+    return false;
+  }
+
+  // Bind memory to buffer
+  res = vkBindBufferMemory(g_vulkan_context->GetDevice(), buffer, memory, 0);
+  if (res != VK_SUCCESS)
+  {
+    LOG_VULKAN_ERROR(res, "vkBindBufferMemory failed: ");
+    vkDestroyBuffer(g_vulkan_context->GetDevice(), buffer, nullptr);
+    vkFreeMemory(g_vulkan_context->GetDevice(), memory, nullptr);
+    return false;
+  }
+
+  // Map this buffer into user-space
+  void* mapped_ptr = nullptr;
+  res = vkMapMemory(g_vulkan_context->GetDevice(), memory, 0, m_size, 0, &mapped_ptr);
+  if (res != VK_SUCCESS)
+  {
+    LOG_VULKAN_ERROR(res, "vkMapMemory failed: ");
+    vkDestroyBuffer(g_vulkan_context->GetDevice(), buffer, nullptr);
+    vkFreeMemory(g_vulkan_context->GetDevice(), memory, nullptr);
+    return false;
+  }
+
+  // Unmap current host pointer (if there was a previous buffer)
+  if (m_host_pointer)
+    vkUnmapMemory(g_vulkan_context->GetDevice(), m_memory);
+
+  // Destroy the backings for the buffer after the command buffer executes
+  if (m_buffer != VK_NULL_HANDLE)
+    g_command_buffer_mgr->DeferBufferDestruction(m_buffer);
+  if (m_memory != VK_NULL_HANDLE)
+    g_command_buffer_mgr->DeferDeviceMemoryDestruction(m_memory);
+
+  // Replace with the new buffer
+  m_buffer = buffer;
+  m_memory = memory;
+  m_host_pointer = reinterpret_cast<u8*>(mapped_ptr);
+  m_current_offset = 0;
+  m_current_gpu_position = 0;
+  m_tracked_fences.clear();
+  return true;
+}
+
+bool StreamBuffer::ReserveMemory(u32 num_bytes, u32 alignment)
+{
+  const u32 required_bytes = num_bytes + alignment;
+
+  // Check for sane allocations
+  if (required_bytes > m_size)
+  {
+    PanicAlertFmt("Attempting to allocate {} bytes from a {} byte stream buffer", num_bytes,
+                  m_size);
+
+    return false;
+  }
+
+  // Is the GPU behind or up to date with our current offset?
+  UpdateCurrentFencePosition();
+  if (m_current_offset >= m_current_gpu_position)
+  {
+    const u32 remaining_bytes = m_size - m_current_offset;
+    if (required_bytes <= remaining_bytes)
+    {
+      // Place at the current position, after the GPU position.
+      m_current_offset = Common::AlignUp(m_current_offset, alignment);
+      m_last_allocation_size = num_bytes;
+      return true;
+    }
+
+    // Check for space at the start of the buffer
+    // We use < here because we don't want to have the case of m_current_offset ==
+    // m_current_gpu_position. That would mean the code above would assume the
+    // GPU has caught up to us, which it hasn't.
+    if (required_bytes < m_current_gpu_position)
+    {
+      // Reset offset to zero, since we're allocating behind the gpu now
+      m_current_offset = 0;
+      m_last_allocation_size = num_bytes;
+      return true;
+    }
+  }
+
+  // Is the GPU ahead of our current offset?
+  if (m_current_offset < m_current_gpu_position)
+  {
+    // We have from m_current_offset..m_current_gpu_position space to use.
+    const u32 remaining_bytes = m_current_gpu_position - m_current_offset;
+    if (required_bytes < remaining_bytes)
+    {
+      // Place at the current position, since this is still behind the GPU.
+      m_current_offset = Common::AlignUp(m_current_offset, alignment);
+      m_last_allocation_size = num_bytes;
+      return true;
+    }
+  }
+
+  // Can we find a fence to wait on that will give us enough memory?
+  if (WaitForClearSpace(required_bytes))
+  {
+    m_current_offset = Common::AlignUp(m_current_offset, alignment);
+    m_last_allocation_size = num_bytes;
+    return true;
+  }
+
+  // We tried everything we could, and still couldn't get anything. This means that too much space
+  // in the buffer is being used by the command buffer currently being recorded. Therefore, the
+  // only option is to execute it, and wait until it's done.
+  return false;
+}
+
+void StreamBuffer::CommitMemory(u32 final_num_bytes)
+{
+  ASSERT((m_current_offset + final_num_bytes) <= m_size);
+  ASSERT(final_num_bytes <= m_last_allocation_size);
+
+  // For non-coherent mappings, flush the memory range
+  if (!m_coherent_mapping)
+  {
+    VkMappedMemoryRange range = {VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE, nullptr, m_memory,
+                                 m_current_offset, final_num_bytes};
+    vkFlushMappedMemoryRanges(g_vulkan_context->GetDevice(), 1, &range);
+  }
+
+  m_current_offset += final_num_bytes;
+}
+
+void StreamBuffer::UpdateCurrentFencePosition()
+{
+  // Don't create a tracking entry if the GPU is caught up with the buffer.
+  if (m_current_offset == m_current_gpu_position)
+    return;
+
+  // Has the offset changed since the last fence?
+  const u64 counter = g_command_buffer_mgr->GetCurrentFenceCounter();
+  if (!m_tracked_fences.empty() && m_tracked_fences.back().first == counter)
+  {
+    // Still haven't executed a command buffer, so just update the offset.
+    m_tracked_fences.back().second = m_current_offset;
+    return;
+  }
+
+  // New buffer, so update the GPU position while we're at it.
+  UpdateGPUPosition();
+  m_tracked_fences.emplace_back(counter, m_current_offset);
+}
+
+void StreamBuffer::UpdateGPUPosition()
+{
+  auto start = m_tracked_fences.begin();
+  auto end = start;
+
+  const u64 completed_counter = g_command_buffer_mgr->GetCompletedFenceCounter();
+  while (end != m_tracked_fences.end() && completed_counter >= end->first)
+  {
+    m_current_gpu_position = end->second;
+    ++end;
+  }
+
+  if (start != end)
+    m_tracked_fences.erase(start, end);
+}
+
+bool StreamBuffer::WaitForClearSpace(u32 num_bytes)
+{
+  u32 new_offset = 0;
+  u32 new_gpu_position = 0;
+
+  auto iter = m_tracked_fences.begin();
+  for (; iter != m_tracked_fences.end(); ++iter)
+  {
+    // Would this fence bring us in line with the GPU?
+    // This is the "last resort" case, where a command buffer execution has been forced
+    // after no additional data has been written to it, so we can assume that after the
+    // fence has been signaled the entire buffer is now consumed.
+    u32 gpu_position = iter->second;
+    if (m_current_offset == gpu_position)
+    {
+      new_offset = 0;
+      new_gpu_position = 0;
+      break;
+    }
+
+    // Assuming that we wait for this fence, are we allocating in front of the GPU?
+    if (m_current_offset > gpu_position)
+    {
+      // This would suggest the GPU has now followed us and wrapped around, so we have from
+      // m_current_position..m_size free, as well as and 0..gpu_position.
+      const u32 remaining_space_after_offset = m_size - m_current_offset;
+      if (remaining_space_after_offset >= num_bytes)
+      {
+        // Switch to allocating in front of the GPU, using the remainder of the buffer.
+        new_offset = m_current_offset;
+        new_gpu_position = gpu_position;
+        break;
+      }
+
+      // We can wrap around to the start, behind the GPU, if there is enough space.
+      // We use > here because otherwise we'd end up lining up with the GPU, and then the
+      // allocator would assume that the GPU has consumed what we just wrote.
+      if (gpu_position > num_bytes)
+      {
+        new_offset = 0;
+        new_gpu_position = gpu_position;
+        break;
+      }
+    }
+    else
+    {
+      // We're currently allocating behind the GPU. This would give us between the current
+      // offset and the GPU position worth of space to work with. Again, > because we can't
+      // align the GPU position with the buffer offset.
+      u32 available_space_inbetween = gpu_position - m_current_offset;
+      if (available_space_inbetween > num_bytes)
+      {
+        // Leave the offset as-is, but update the GPU position.
+        new_offset = m_current_offset;
+        new_gpu_position = gpu_position;
+        break;
+      }
+    }
+  }
+
+  // Did any fences satisfy this condition?
+  // Has the command buffer been executed yet? If not, the caller should execute it.
+  if (iter == m_tracked_fences.end() ||
+      iter->first == g_command_buffer_mgr->GetCurrentFenceCounter())
+  {
+    return false;
+  }
+
+  // Wait until this fence is signaled. This will fire the callback, updating the GPU position.
+  g_command_buffer_mgr->WaitForFenceCounter(iter->first);
+  m_tracked_fences.erase(m_tracked_fences.begin(),
+                         m_current_offset == iter->second ? m_tracked_fences.end() : ++iter);
+  m_current_offset = new_offset;
+  m_current_gpu_position = new_gpu_position;
+  return true;
+}
+
+}  // namespace Vulkan