Implement zero-sized QuerySet

- Add zero-sized implementation in each backend.
- Test creating zero-sized query set for each type.

Bug: dawn:954
Change-Id: Ib2b8a7d890dae6ee40f5a05aac570a4600dedab8
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/56260
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jiawei Shao <jiawei.shao@intel.com>
Commit-Queue: Hao Li <hao.x.li@intel.com>

src/dawn_native/d3d12/QuerySetD3D12.cpp

@@ -43,7 +43,7 @@ namespace dawn_native { namespace d3d12 {
     MaybeError QuerySet::Initialize() {
         D3D12_QUERY_HEAP_DESC queryHeapDesc = {};
         queryHeapDesc.Type = D3D12QueryHeapType(GetQueryType());
-        queryHeapDesc.Count = GetQueryCount();
+        queryHeapDesc.Count = std::max(GetQueryCount(), uint32_t(1u));
 
         ID3D12Device* d3d12Device = ToBackend(GetDevice())->GetD3D12Device();
         return CheckOutOfMemoryHRESULT(

src/dawn_native/metal/QuerySetMTL.mm

@@ -42,7 +42,7 @@ namespace dawn_native { namespace metal {
             }
             ASSERT(descriptor.counterSet != nullptr);
 
-            descriptor.sampleCount = count;
+            descriptor.sampleCount = static_cast<NSUInteger>(std::max(count, uint32_t(1u)));
             descriptor.storageMode = MTLStorageModePrivate;
             if (device->IsToggleEnabled(Toggle::MetalUseSharedModeForCounterSampleBuffer)) {
                 descriptor.storageMode = MTLStorageModeShared;
@@ -75,7 +75,8 @@ namespace dawn_native { namespace metal {
         switch (GetQueryType()) {
             case wgpu::QueryType::Occlusion: {
                 // Create buffer for writing 64-bit results.
-                NSUInteger bufferSize = static_cast<NSUInteger>(GetQueryCount() * sizeof(uint64_t));
+                NSUInteger bufferSize = static_cast<NSUInteger>(
+                    std::max(GetQueryCount() * sizeof(uint64_t), size_t(4u)));
                 mVisibilityBuffer = AcquireNSPRef([device->GetMTLDevice()
                     newBufferWithLength:bufferSize
                                 options:MTLResourceStorageModePrivate]);

src/dawn_native/vulkan/QuerySetVk.cpp

@@ -77,7 +77,7 @@ namespace dawn_native { namespace vulkan {
         createInfo.pNext = NULL;
         createInfo.flags = 0;
         createInfo.queryType = VulkanQueryType(GetQueryType());
-        createInfo.queryCount = GetQueryCount();
+        createInfo.queryCount = std::max(GetQueryCount(), uint32_t(1u));
         if (GetQueryType() == wgpu::QueryType::PipelineStatistics) {
             createInfo.pipelineStatistics =
                 VulkanQueryPipelineStatisticFlags(GetPipelineStatistics());

src/tests/end2end/QueryTests.cpp

@@ -215,6 +215,9 @@ class OcclusionQueryTests : public QueryTests {
 
 // Test creating query set with the type of Occlusion
 TEST_P(OcclusionQueryTests, QuerySetCreation) {
+    // Zero-sized query set is allowed.
+    CreateOcclusionQuerySet(0);
+
     CreateOcclusionQuerySet(1);
 }
 
@@ -461,19 +464,30 @@ class PipelineStatisticsQueryTests : public QueryTests {
 
         return requiredExtensions;
     }
+
+    wgpu::QuerySet CreateQuerySetForPipelineStatistics(
+        uint32_t queryCount,
+        std::vector<wgpu::PipelineStatisticName> pipelineStatistics = {}) {
+        wgpu::QuerySetDescriptor descriptor;
+        descriptor.count = queryCount;
+        descriptor.type = wgpu::QueryType::PipelineStatistics;
+
+        if (pipelineStatistics.size() > 0) {
+            descriptor.pipelineStatistics = pipelineStatistics.data();
+            descriptor.pipelineStatisticsCount = pipelineStatistics.size();
+        }
+        return device.CreateQuerySet(&descriptor);
+    }
 };
 
 // Test creating query set with the type of PipelineStatistics
 TEST_P(PipelineStatisticsQueryTests, QuerySetCreation) {
-    wgpu::QuerySetDescriptor descriptor;
-    descriptor.count = 1;
-    descriptor.type = wgpu::QueryType::PipelineStatistics;
-    wgpu::PipelineStatisticName pipelineStatistics[2] = {
-        wgpu::PipelineStatisticName::ClipperInvocations,
-        wgpu::PipelineStatisticName::VertexShaderInvocations};
-    descriptor.pipelineStatistics = pipelineStatistics;
-    descriptor.pipelineStatisticsCount = 2;
-    device.CreateQuerySet(&descriptor);
+    // Zero-sized query set is allowed.
+    CreateQuerySetForPipelineStatistics(0, {wgpu::PipelineStatisticName::ClipperInvocations,
+                                            wgpu::PipelineStatisticName::VertexShaderInvocations});
+
+    CreateQuerySetForPipelineStatistics(1, {wgpu::PipelineStatisticName::ClipperInvocations,
+                                            wgpu::PipelineStatisticName::VertexShaderInvocations});
 }
 
 DAWN_INSTANTIATE_TEST(PipelineStatisticsQueryTests,
@@ -529,6 +543,9 @@ class TimestampQueryTests : public QueryTests {
 
 // Test creating query set with the type of Timestamp
 TEST_P(TimestampQueryTests, QuerySetCreation) {
+    // Zero-sized query set is allowed.
+    CreateQuerySetForTimestamp(0);
+
     CreateQuerySetForTimestamp(1);
 }