Add tests and fix (create) mapping zero-sized buffers
When creating a zero-sized buffer mapped, StagingBuffer creation
is skipped. This required adding a new MappedAtCreation state
since mStagingBuffer couldn't be used as a tag value for that.
Made the OpenGL backend always create non-zero-sized buffers.
Finally added tests for MapRead/WriteAsync and CreateBufferMapped
of zero-sized buffers.
Bug: dawn:446
Change-Id: I04f6fe98fd646f1867c21065cd1cd33a1595e19f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/21481
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/dawn_native/Buffer.cpp b/src/dawn_native/Buffer.cpp
index 46d00d1..4df366a 100644
--- a/src/dawn_native/Buffer.cpp
+++ b/src/dawn_native/Buffer.cpp
@@ -163,14 +163,22 @@
ASSERT(!IsError());
ASSERT(mappedPointer != nullptr);
- mState = BufferState::Mapped;
-
+ // Mappable buffers don't use a staging buffer and are just as if mapped through MapAsync.
if (IsMapWritable()) {
DAWN_TRY(MapAtCreationImpl(mappedPointer));
+ mState = BufferState::Mapped;
ASSERT(*mappedPointer != nullptr);
return {};
}
+ mState = BufferState::MappedAtCreation;
+
+ // 0-sized buffers are not supposed to be written to, Return back any non-null pointer.
+ if (mSize == 0) {
+ *mappedPointer = reinterpret_cast<uint8_t*>(intptr_t(0xCAFED00D));
+ return {};
+ }
+
// If any of these fail, the buffer will be deleted and replaced with an
// error buffer.
// TODO(enga): Suballocate and reuse memory from a larger staging buffer so we don't create
@@ -190,6 +198,7 @@
case BufferState::Destroyed:
return DAWN_VALIDATION_ERROR("Destroyed buffer used in a submit");
case BufferState::Mapped:
+ case BufferState::MappedAtCreation:
return DAWN_VALIDATION_ERROR("Buffer used in a submit while mapped");
case BufferState::Unmapped:
return {};
@@ -309,11 +318,15 @@
ASSERT(!IsError());
if (mState == BufferState::Mapped) {
- if (mStagingBuffer == nullptr) {
- Unmap();
+ Unmap();
+ } else if (mState == BufferState::MappedAtCreation) {
+ if (mStagingBuffer != nullptr) {
+ mStagingBuffer.reset();
+ } else {
+ ASSERT(mSize == 0);
}
- mStagingBuffer.reset();
}
+
DestroyInternal();
}
@@ -342,9 +355,7 @@
}
ASSERT(!IsError());
- if (mStagingBuffer != nullptr) {
- GetDevice()->ConsumedError(CopyFromStagingBuffer());
- } else {
+ if (mState == BufferState::Mapped) {
// A map request can only be called once, so this will fire only if the request wasn't
// completed before the Unmap.
// Callbacks are not fired if there is no callback registered, so this is correct for
@@ -352,11 +363,20 @@
CallMapReadCallback(mMapSerial, WGPUBufferMapAsyncStatus_Unknown, nullptr, 0u);
CallMapWriteCallback(mMapSerial, WGPUBufferMapAsyncStatus_Unknown, nullptr, 0u);
UnmapImpl();
+
+ mMapReadCallback = nullptr;
+ mMapWriteCallback = nullptr;
+ mMapUserdata = 0;
+
+ } else if (mState == BufferState::MappedAtCreation) {
+ if (mStagingBuffer != nullptr) {
+ GetDevice()->ConsumedError(CopyFromStagingBuffer());
+ } else {
+ ASSERT(mSize == 0);
+ }
}
+
mState = BufferState::Unmapped;
- mMapReadCallback = nullptr;
- mMapWriteCallback = nullptr;
- mMapUserdata = 0;
}
MaybeError BufferBase::ValidateMap(wgpu::BufferUsage requiredUsage,
@@ -369,6 +389,7 @@
switch (mState) {
case BufferState::Mapped:
+ case BufferState::MappedAtCreation:
return DAWN_VALIDATION_ERROR("Buffer already mapped");
case BufferState::Destroyed:
return DAWN_VALIDATION_ERROR("Buffer is destroyed");
@@ -390,6 +411,7 @@
switch (mState) {
case BufferState::Mapped:
+ case BufferState::MappedAtCreation:
// A buffer may be in the Mapped state if it was created with CreateBufferMapped
// even if it did not have a mappable usage.
return {};
diff --git a/src/dawn_native/Buffer.h b/src/dawn_native/Buffer.h
index b0e45f9..b05e341 100644
--- a/src/dawn_native/Buffer.h
+++ b/src/dawn_native/Buffer.h
@@ -35,6 +35,7 @@
enum class BufferState {
Unmapped,
Mapped,
+ MappedAtCreation,
Destroyed,
};
diff --git a/src/dawn_native/opengl/BufferGL.cpp b/src/dawn_native/opengl/BufferGL.cpp
index a7f880a..dc9beef 100644
--- a/src/dawn_native/opengl/BufferGL.cpp
+++ b/src/dawn_native/opengl/BufferGL.cpp
@@ -22,9 +22,13 @@
Buffer::Buffer(Device* device, const BufferDescriptor* descriptor)
: BufferBase(device, descriptor) {
+ // TODO(cwallez@chromium.org): Have a global "zero" buffer instead of creating a new 4-byte
+ // buffer?
+ uint64_t size = std::max(GetSize(), uint64_t(4u));
+
device->gl.GenBuffers(1, &mBuffer);
device->gl.BindBuffer(GL_ARRAY_BUFFER, mBuffer);
- device->gl.BufferData(GL_ARRAY_BUFFER, GetSize(), nullptr, GL_STATIC_DRAW);
+ device->gl.BufferData(GL_ARRAY_BUFFER, size, nullptr, GL_STATIC_DRAW);
}
Buffer::~Buffer() {
diff --git a/src/dawn_wire/server/ServerBuffer.cpp b/src/dawn_wire/server/ServerBuffer.cpp
index 89ebacb..8498512 100644
--- a/src/dawn_wire/server/ServerBuffer.cpp
+++ b/src/dawn_wire/server/ServerBuffer.cpp
@@ -202,6 +202,7 @@
// to Unmap and attempt to update mapped data of an error buffer.
return false;
}
+
// Deserialize the flush info and flush updated data from the handle into the target
// of the handle. The target is set via WriteHandle::SetTarget.
return buffer->writeHandle->DeserializeFlush(writeFlushInfo,
diff --git a/src/tests/end2end/BufferTests.cpp b/src/tests/end2end/BufferTests.cpp
index 61f4e34..ceaf27c 100644
--- a/src/tests/end2end/BufferTests.cpp
+++ b/src/tests/end2end/BufferTests.cpp
@@ -108,6 +108,17 @@
UnmapBuffer(buffer);
}
+// Test mapping a zero-sized buffer.
+TEST_P(BufferMapReadTests, ZeroSized) {
+ wgpu::BufferDescriptor descriptor;
+ descriptor.size = 0;
+ descriptor.usage = wgpu::BufferUsage::MapRead | wgpu::BufferUsage::CopyDst;
+ wgpu::Buffer buffer = device.CreateBuffer(&descriptor);
+
+ MapReadAsyncAndWait(buffer);
+ UnmapBuffer(buffer);
+}
+
DAWN_INSTANTIATE_TEST(BufferMapReadTests, D3D12Backend(), MetalBackend(), OpenGLBackend(), VulkanBackend());
class BufferMapWriteTests : public DawnTest {
@@ -202,6 +213,17 @@
EXPECT_BUFFER_U32_RANGE_EQ(myData.data(), buffer, 0, kDataSize);
}
+// Test mapping a zero-sized buffer.
+TEST_P(BufferMapWriteTests, ZeroSized) {
+ wgpu::BufferDescriptor descriptor;
+ descriptor.size = 0;
+ descriptor.usage = wgpu::BufferUsage::MapWrite | wgpu::BufferUsage::CopySrc;
+ wgpu::Buffer buffer = device.CreateBuffer(&descriptor);
+
+ MapWriteAsyncAndWait(buffer);
+ UnmapBuffer(buffer);
+}
+
// Stress test mapping many buffers.
TEST_P(BufferMapWriteTests, ManyWrites) {
constexpr uint32_t kDataSize = 1000;
@@ -370,6 +392,21 @@
EXPECT_BUFFER_U32_RANGE_EQ(myData.data(), result.buffer, 0, kDataSize);
}
+// Test destroying a non-mappable buffer mapped at creation.
+// This is a regression test for an issue where the D3D12 backend thought the buffer was actually
+// mapped and tried to unlock the heap residency (when actually the buffer was using a staging
+// buffer)
+TEST_P(CreateBufferMappedTests, DestroyNonMappableWhileMappedForCreation) {
+ wgpu::CreateBufferMappedResult result = CreateBufferMapped(wgpu::BufferUsage::CopySrc, 4);
+ result.buffer.Destroy();
+}
+
+// Test destroying a mappable buffer mapped at creation.
+TEST_P(CreateBufferMappedTests, DestroyMappableWhileMappedForCreation) {
+ wgpu::CreateBufferMappedResult result = CreateBufferMapped(wgpu::BufferUsage::MapRead, 4);
+ result.buffer.Destroy();
+}
+
// Test that mapping a buffer is valid after CreateBufferMapped and Unmap
TEST_P(CreateBufferMappedTests, CreateThenMapSuccess) {
static uint32_t myData = 230502;
@@ -437,6 +474,48 @@
ASSERT_DEVICE_ERROR(device.CreateBuffer(&descriptor));
}
+// Test that creating a zero-sized buffer mapped is allowed.
+TEST_P(CreateBufferMappedTests, ZeroSized) {
+ wgpu::BufferDescriptor descriptor;
+ descriptor.size = 0;
+ descriptor.usage = wgpu::BufferUsage::Vertex;
+ wgpu::CreateBufferMappedResult result = device.CreateBufferMapped(&descriptor);
+
+ ASSERT_EQ(0u, result.dataLength);
+ ASSERT_NE(nullptr, result.data);
+
+ // Check that unmapping the buffer works too.
+ UnmapBuffer(result.buffer);
+}
+
+// Test that creating a zero-sized mapppable buffer mapped. (it is a different code path)
+TEST_P(CreateBufferMappedTests, ZeroSizedMappableBuffer) {
+ wgpu::BufferDescriptor descriptor;
+ descriptor.size = 0;
+ descriptor.usage = wgpu::BufferUsage::MapWrite;
+ wgpu::CreateBufferMappedResult result = device.CreateBufferMapped(&descriptor);
+
+ ASSERT_EQ(0u, result.dataLength);
+ ASSERT_NE(nullptr, result.data);
+
+ // Check that unmapping the buffer works too.
+ UnmapBuffer(result.buffer);
+}
+
+// Test that creating a zero-sized error buffer mapped. (it is a different code path)
+TEST_P(CreateBufferMappedTests, ZeroSizedErrorBuffer) {
+ DAWN_SKIP_TEST_IF(IsDawnValidationSkipped());
+
+ wgpu::BufferDescriptor descriptor;
+ descriptor.size = 0;
+ descriptor.usage = wgpu::BufferUsage::MapWrite | wgpu::BufferUsage::Storage;
+ wgpu::CreateBufferMappedResult result;
+ ASSERT_DEVICE_ERROR(result = device.CreateBufferMapped(&descriptor));
+
+ ASSERT_EQ(0u, result.dataLength);
+ ASSERT_NE(nullptr, result.data);
+}
+
DAWN_INSTANTIATE_TEST(CreateBufferMappedTests,
D3D12Backend(),
D3D12Backend({}, {"use_d3d12_resource_heap_tier2"}),
@@ -446,6 +525,7 @@
class BufferTests : public DawnTest {};
+// Test that creating a zero-buffer is allowed.
TEST_P(BufferTests, ZeroSizedBuffer) {
wgpu::BufferDescriptor desc;
desc.size = 0;
@@ -453,6 +533,17 @@
device.CreateBuffer(&desc);
}
+// Test that creating a very large buffers fails gracefully.
+TEST_P(BufferTests, LargeBufferFails) {
+ // TODO(http://crbug.com/dawn/27): Missing support.
+ DAWN_SKIP_TEST_IF(IsOpenGL());
+
+ wgpu::BufferDescriptor descriptor;
+ descriptor.size = std::numeric_limits<uint64_t>::max();
+ descriptor.usage = wgpu::BufferUsage::MapRead | wgpu::BufferUsage::CopyDst;
+ ASSERT_DEVICE_ERROR(device.CreateBuffer(&descriptor));
+}
+
DAWN_INSTANTIATE_TEST(BufferTests,
D3D12Backend(),
MetalBackend(),
