Crafter.Graphics/tests/VulkanBufferResizeReuse/main.cpp

118 lines
4.4 KiB
C++

//SPDX-License-Identifier: LGPL-3.0-only
//SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®
// Regression test for issue #63: VulkanBuffer::Resize used to unconditionally
// destroy + reallocate. It now reuses the existing allocation in place when the
// new request still fits within the created capacity AND the immutable-at-create
// properties match (usage flags are fixed at create; the chosen memory type must
// still satisfy the required property flags). The reuse path only shrinks `size`
// and issues no Vulkan call.
//
// The guard is pure logic over recorded fields, so this test drives it directly
// with no GPU device: it stamps a fake non-null buffer handle plus capacity /
// usage / chosen-flags, then calls Resize. With Device::device == VK_NULL_HANDLE
// any real destroy/reallocate would dereference a null dispatch handle and
// crash — so reaching the line after a reuse Resize is the assertion that the
// in-place path was taken. The realloc path (flag/size mismatch) is intentionally
// not exercised here because it would issue real Vulkan calls.
#include <cstdint>
#include <cstdlib>
#include "vulkan/vulkan.h"
import Crafter.Graphics;
import std;
using namespace Crafter;
namespace {
int failures = 0;
void Check(bool ok, std::string_view what) {
std::println("{} {}", ok ? "PASS" : "FAIL", what);
if (!ok) ++failures;
}
constexpr auto DEVICE_LOCAL = VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
constexpr auto HOST_VISIBLE = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;
constexpr auto HOST_COHERENT = VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
constexpr VkBufferUsageFlags2 USAGE =
VK_BUFFER_USAGE_2_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_2_SHADER_DEVICE_ADDRESS_BIT;
// A fake non-null, non-dereferenced handle: Resize's reuse path never touches it.
VkBuffer FakeHandle() {
return reinterpret_cast<VkBuffer>(static_cast<std::uintptr_t>(0x1));
}
// Stamp a buffer into the "already created with capacity C" state without
// touching the GPU, then neutralise it so the destructor's Clear() is skipped.
template <typename Buf>
void NeutraliseHandle(Buf& buf) {
buf.buffer = VK_NULL_HANDLE;
}
} // namespace
int main() {
Check(Device::device == VK_NULL_HANDLE,
"no Vulkan device created — a real reallocate would fault");
{
// Shrink within capacity, flags match → reuse in place, only size shrinks.
VulkanBuffer<float, false> buf;
buf.buffer = FakeHandle();
buf.capacity = 16 * sizeof(float);
buf.size = 16 * sizeof(float);
buf.usageFlagsCreated = USAGE;
buf.memoryPropertyFlagsChosen = HOST_VISIBLE | HOST_COHERENT;
buf.Resize(USAGE, HOST_VISIBLE, 4); // 4 floats <= 16-float capacity
Check(buf.buffer == FakeHandle(),
"fitting Resize reuses the existing handle (no realloc)");
Check(buf.size == 4 * sizeof(float),
"reuse updates size to the new logical extent");
Check(buf.capacity == 16 * sizeof(float),
"reuse leaves capacity at the original allocation size");
NeutraliseHandle(buf);
}
{
// Exact-fit request (size == capacity) is still a reuse.
VulkanBuffer<float, false> buf;
buf.buffer = FakeHandle();
buf.capacity = 8 * sizeof(float);
buf.size = 2 * sizeof(float);
buf.usageFlagsCreated = USAGE;
buf.memoryPropertyFlagsChosen = HOST_VISIBLE;
buf.Resize(USAGE, HOST_VISIBLE, 8);
Check(buf.buffer == FakeHandle() && buf.size == 8 * sizeof(float),
"exact-capacity Resize reuses the allocation");
NeutraliseHandle(buf);
}
{
// Reuse requires the chosen memory type to still satisfy the required
// flags. Chosen type carries DEVICE_LOCAL, so a request for it is
// satisfied and reuse is allowed.
VulkanBuffer<float, false> buf;
buf.buffer = FakeHandle();
buf.capacity = 8 * sizeof(float);
buf.size = 8 * sizeof(float);
buf.usageFlagsCreated = USAGE;
buf.memoryPropertyFlagsChosen = HOST_VISIBLE | DEVICE_LOCAL;
buf.Resize(USAGE, DEVICE_LOCAL, 4);
Check(buf.buffer == FakeHandle() && buf.size == 4 * sizeof(float),
"reuse allowed when chosen memory type satisfies required flags");
NeutraliseHandle(buf);
}
if (failures != 0) {
std::println("{} check(s) failed", failures);
return EXIT_FAILURE;
}
std::println("all checks passed");
return EXIT_SUCCESS;
}