Enable WebGPU tests with descriptors (#294)

Add GPUTest.asyncReinitDeviceWithDescriptor. Calling this will
reinitialize `this.device` with a device with the provided descriptor
(ensuring that `this.device` has not actually been used already).

src/common/framework/gpu/device_pool.ts

@@ -1,56 +1,61 @@
-import { assert, raceWithRejectOnTimeout, unreachable, assertReject } from '../util/util.js';
+import { SkipTestCase } from '../fixture.js';
+import {
+  assert,
+  raceWithRejectOnTimeout,
+  unreachable,
+  assertReject,
+  objectEquals,
+} from '../util/util.js';
 
 import { getGPU } from './implementation.js';
 
-interface DeviceHolder {
-  acquired: boolean; // whether the device is currently in use by a test
-  device: GPUDevice;
-  lostReason?: string; // initially undefined; becomes set when the device is lost
+export interface DeviceProvider {
+  acquire(): GPUDevice;
 }
 
 class TestFailedButDeviceReusable extends Error {}
 export class TestOOMedShouldAttemptGC extends Error {}
 
-const kPopErrorScopeTimeoutMS = 5000;
-
 export class DevicePool {
-  failed: boolean = false; // if device init failed once, never try again
-  holder?: DeviceHolder = undefined; // undefined if "uninitialized" (not yet initialized, or lost)
+  /** Device with no descriptor. */
+  private defaultHolder: DeviceHolder | 'uninitialized' | 'failed' = 'uninitialized';
+  /** Devices with descriptors. */
+  private nonDefaultHolders = new DescriptorToDeviceMap();
 
-  async acquire(): Promise<GPUDevice> {
-    assert(!this.failed, 'WebGPU device previously failed to initialize; not retrying');
-
-    if (this.holder === undefined) {
+  /** Request a device from the pool. */
+  async reserve(desc?: GPUDeviceDescriptor): Promise<DeviceProvider> {
+    // Always attempt to initialize default device, to see if it succeeds.
+    if (this.defaultHolder === 'uninitialized') {
       try {
-        this.holder = await DevicePool.makeHolder();
+        this.defaultHolder = await DeviceHolder.create();
       } catch (ex) {
-        this.failed = true;
-        throw ex;
+        this.defaultHolder = 'failed';
       }
     }
-    assert(!this.holder.acquired, 'Device was in use on DevicePool.acquire');
-    this.holder.acquired = true;
+    assert(this.defaultHolder !== 'failed', 'WebGPU device failed to initialize; not retrying');
 
-    this.beginErrorScopes();
-    return this.holder.device;
+    let holder;
+    if (desc === undefined) {
+      holder = this.defaultHolder;
+    } else {
+      holder = await this.nonDefaultHolders.getOrInsert(desc, () => DeviceHolder.create(desc));
+    }
+
+    assert(holder.state === 'free', 'Device was in use on DevicePool.acquire');
+    holder.state = 'reserved';
+    return holder;
   }
 
   // When a test is done using a device, it's released back into the pool.
   // This waits for error scopes, checks their results, and checks for various error conditions.
-  async release(device: GPUDevice): Promise<void> {
-    const holder = this.holder;
-    assert(holder !== undefined, 'trying to release a device while pool is uninitialized');
-    assert(holder.acquired, 'trying to release a device while already released');
-    assert(device === holder.device, 'Released device was the wrong device');
+  async release(holder: DeviceProvider): Promise<void> {
+    assert(this.defaultHolder instanceof DeviceHolder);
+    assert(holder instanceof DeviceHolder);
+
+    assert(holder.state !== 'free', 'trying to release a device while already released');
 
     try {
-      // Time out if popErrorScope never completes. This could happen due to a browser bug - e.g.,
-      // as of this writing, on Chrome GPU process crash, popErrorScope just hangs.
-      await raceWithRejectOnTimeout(
-        this.endErrorScopes(),
-        kPopErrorScopeTimeoutMS,
-        'finalization popErrorScope timed out'
-      );
+      await holder.ensureRelease();
 
       // (Hopefully if the device was lost, it has been reported by the time endErrorScopes()
       // has finished (or timed out). If not, it could cause a finite number of extra test
@@ -64,66 +69,183 @@ export class DevicePool {
       // Any error that isn't explicitly TestFailedButDeviceReusable forces a new device to be
       // created for the next test.
       if (!(ex instanceof TestFailedButDeviceReusable)) {
-        this.holder = undefined;
+        if (holder === this.defaultHolder) {
+          this.defaultHolder = 'uninitialized';
+        } else {
+          this.nonDefaultHolders.deleteByDevice(holder.device);
+        }
+        // TODO: device.destroy()
       }
       throw ex;
     } finally {
-      // TODO: device.destroy()
-
       // Mark the holder as free. (This only has an effect if the pool still has the holder.)
       // This could be done at the top but is done here to guard against async-races during release.
-      holder.acquired = false;
+      holder.state = 'free';
     }
   }
+}
+
+interface DescriptorToDevice {
+  key: GPUDeviceDescriptor;
+  value: DeviceHolder;
+}
+
+/**
+ * Map from GPUDeviceDescriptor to DeviceHolder.
+ */
+class DescriptorToDeviceMap {
+  private unsupported: GPUDeviceDescriptor[] = [];
+  // TODO: Do something like stringifyPublicParamsUniquely if searching this array gets too slow.
+  private items: Set<DescriptorToDevice> = new Set();
+
+  /** Deletes an item from the map by GPUDevice value. */
+  deleteByDevice(device: GPUDevice): void {
+    for (const item of this.items) {
+      if (item.value.device === device) {
+        this.items.delete(item);
+        return;
+      }
+    }
+  }
+
+  /**
+   * Gets a DeviceHolder from the map if it exists; otherwise, calls create() to create one,
+   * inserts it, and returns it.
+   *
+   * Throws SkipTestCase if devices with this descriptor are unsupported.
+   */
+  async getOrInsert(
+    key: GPUDeviceDescriptor,
+    create: () => Promise<DeviceHolder>
+  ): Promise<DeviceHolder> {
+    // Never retry unsupported configurations.
+    for (const desc of this.unsupported) {
+      if (objectEquals(key, desc)) {
+        throw new SkipTestCase(`GPUDeviceDescriptor previously failed: ${JSON.stringify(key)}`);
+      }
+    }
+
+    // Search for an existing device with the same descriptor.
+    for (const item of this.items) {
+      if (objectEquals(key, item.key)) {
+        // Move the item to the end of the set (most recently used).
+        this.items.delete(item);
+        this.items.add(item);
+        return item.value;
+      }
+    }
+
+    // No existing item was found; add a new one.
+    let value;
+    try {
+      value = await create();
+    } catch (ex) {
+      this.unsupported.push(key);
+      throw new SkipTestCase(
+        `GPUDeviceDescriptor not supported: ${JSON.stringify(key)}\n${ex?.message ?? ''}`
+      );
+    }
+    this.insertAndCleanUp({ key, value });
+    return value;
+  }
+
+  /** Insert an entry, then remove the least-recently-used items if there are too many. */
+  private insertAndCleanUp(kv: DescriptorToDevice) {
+    this.items.add(kv);
+
+    const kMaxEntries = 5;
+    if (this.items.size > kMaxEntries) {
+      // Delete the first (least recently used) item in the set.
+      for (const item of this.items) {
+        this.items.delete(item);
+        return;
+      }
+    }
+  }
+}
+
+/**
+ * DeviceHolder has three states:
+ * - 'free': Free to be used for a new test.
+ * - 'reserved': Reserved by a running test, but has not had error scopes created yet.
+ * - 'acquired': Reserved by a running test, and has had error scopes created.
+ */
+type DeviceHolderState = 'free' | 'reserved' | 'acquired';
+
+/**
+ * Holds a GPUDevice and tracks its state (free/reserved/acquired) and handles device loss.
+ */
+class DeviceHolder implements DeviceProvider {
+  readonly device: GPUDevice;
+  state: DeviceHolderState = 'free';
+  lostReason?: string; // initially undefined; becomes set when the device is lost
 
   // Gets a device and creates a DeviceHolder.
   // If the device is lost, DeviceHolder.lostReason gets set.
-  private static async makeHolder(): Promise<DeviceHolder> {
+  static async create(descriptor?: GPUDeviceDescriptor): Promise<DeviceHolder> {
     const gpu = getGPU();
     const adapter = await gpu.requestAdapter();
-    assert(adapter !== null);
-    const device = await adapter.requestDevice();
-    assert(device !== null);
-
-    const holder: DeviceHolder = {
-      acquired: false,
-      device,
-      lostReason: undefined,
-    };
-    holder.device.lost.then(ev => {
-      holder.lostReason = ev.message;
+    assert(adapter !== null, 'requestAdapter returned null');
+    const device = await adapter.requestDevice(descriptor);
+    assert(device !== null, 'requestDevice returned null');
+
+    return new DeviceHolder(device);
+  }
+
+  private constructor(device: GPUDevice) {
+    this.device = device;
+    this.device.lost.then(ev => {
+      this.lostReason = ev.message;
     });
-    return holder;
   }
 
-  // Create error scopes that wrap the entire test.
-  private beginErrorScopes(): void {
-    assert(this.holder !== undefined);
-    this.holder.device.pushErrorScope('out-of-memory');
-    this.holder.device.pushErrorScope('validation');
+  acquire(): GPUDevice {
+    assert(this.state === 'reserved');
+    this.state = 'acquired';
+    this.device.pushErrorScope('out-of-memory');
+    this.device.pushErrorScope('validation');
+    return this.device;
+  }
+
+  async ensureRelease(): Promise<void> {
+    const kPopErrorScopeTimeoutMS = 5000;
+
+    assert(this.state !== 'free');
+    try {
+      if (this.state === 'acquired') {
+        // Time out if popErrorScope never completes. This could happen due to a browser bug - e.g.,
+        // as of this writing, on Chrome GPU process crash, popErrorScope just hangs.
+        await raceWithRejectOnTimeout(
+          this.release(),
+          kPopErrorScopeTimeoutMS,
+          'finalization popErrorScope timed out'
+        );
+      }
+    } finally {
+      this.state = 'free';
+    }
   }
 
-  // End the whole-test error scopes. Check that there are no extra error scopes, and that no
-  // otherwise-uncaptured errors occurred during the test.
-  private async endErrorScopes(): Promise<void> {
-    assert(this.holder !== undefined);
+  private async release(): Promise<void> {
+    // End the whole-test error scopes. Check that there are no extra error scopes, and that no
+    // otherwise-uncaptured errors occurred during the test.
     let gpuValidationError: GPUValidationError | GPUOutOfMemoryError | null;
     let gpuOutOfMemoryError: GPUValidationError | GPUOutOfMemoryError | null;
 
     try {
       // May reject if the device was lost.
-      gpuValidationError = await this.holder.device.popErrorScope();
-      gpuOutOfMemoryError = await this.holder.device.popErrorScope();
+      gpuValidationError = await this.device.popErrorScope();
+      gpuOutOfMemoryError = await this.device.popErrorScope();
     } catch (ex) {
       assert(
-        this.holder.lostReason !== undefined,
-        "popErrorScope failed, but device.lost hasn't fired (yet)"
+        this.lostReason !== undefined,
+        'popErrorScope failed; should only happen if device has been lost'
       );
       throw ex;
     }
 
     await assertReject(
-      this.holder.device.popErrorScope(),
+      this.device.popErrorScope(),
       'There was an extra error scope on the stack after a test'
     );
 

src/webgpu/examples.spec.ts

@@ -4,6 +4,7 @@ Examples of writing CTS tests with various features.
 Start here when looking for examples of basic framework usage.
 `;
 
+import { pbool } from '../common/framework/params_builder.js';
 import { makeTestGroup } from '../common/framework/test_group.js';
 
 import { GPUTest } from './gpu_test.js';
@@ -100,3 +101,43 @@ g.test('gpu,buffers').fn(async t => {
   // Like shouldReject, it must be awaited.
   t.expectContents(src, data);
 });
+
+// One of the following two tests should be skipped on most platforms.
+
+g.test('gpu,with_texture_compression,bc')
+  .params(pbool('textureCompressionBC'))
+  .fn(async t => {
+    const { textureCompressionBC } = t.params;
+
+    if (textureCompressionBC) {
+      await t.asyncReinitDeviceWithDescriptor({ extensions: ['texture-compression-bc'] });
+    }
+
+    const shouldError = !textureCompressionBC;
+    t.expectGPUError(
+      'validation',
+      () => {
+        t.device.createTexture({
+          format: 'bc1-rgba-unorm',
+          size: [4, 4, 1],
+          usage: GPUTextureUsage.SAMPLED,
+        });
+      },
+      shouldError
+    );
+  });
+
+g.test('gpu,with_texture_compression,etc')
+  .params(pbool('textureCompressionETC'))
+  .fn(async t => {
+    const { textureCompressionETC } = t.params;
+
+    if (textureCompressionETC) {
+      await t.asyncReinitDeviceWithDescriptor({
+        extensions: ['texture-compression-etc' as GPUExtensionName],
+      });
+    }
+
+    t.device;
+    // TODO: Should actually test createTexture with an ETC format here.
+  });