Merge pull request #21049 from calixteman/load_gpu

Unconditionally create a gpu device

src/core/evaluator.js

@@ -105,7 +105,7 @@ const DefaultPartialEvaluatorOptions = Object.freeze({
   iccUrl: null,
   standardFontDataUrl: null,
   wasmUrl: null,
-  prepareWebGPU: null,
+  hasGPU: false,
 });
 
 const PatternType = {
@@ -1520,8 +1520,7 @@ class PartialEvaluator {
         resources,
         this._pdfFunctionFactory,
         this.globalColorSpaceCache,
-        localColorSpaceCache,
-        this.options.prepareWebGPU
+        localColorSpaceCache
       );
       patternIR = shadingFill.getIR();
     } catch (reason) {

src/core/pattern.js

@@ -46,18 +46,24 @@ const ShadingType = {
 };
 
 class Pattern {
+  // eslint-disable-next-line no-unused-private-class-members
+  static #hasGPU = false;
+
   constructor() {
     unreachable("Cannot initialize Pattern.");
   }
 
+  static setOptions({ hasGPU }) {
+    this.#hasGPU = hasGPU;
+  }
+
   static parseShading(
     shading,
     xref,
     res,
     pdfFunctionFactory,
     globalColorSpaceCache,
-    localColorSpaceCache,
-    prepareWebGPU = null
+    localColorSpaceCache
   ) {
     const dict = shading instanceof BaseStream ? shading.dict : shading;
     const type = dict.get("ShadingType");
@@ -65,7 +71,6 @@ class Pattern {
     try {
       switch (type) {
         case ShadingType.FUNCTION_BASED:
-          prepareWebGPU?.();
           return new FunctionBasedShading(
             dict,
             xref,
@@ -88,7 +93,6 @@ class Pattern {
         case ShadingType.LATTICE_FORM_MESH:
         case ShadingType.COONS_PATCH_MESH:
         case ShadingType.TENSOR_PATCH_MESH:
-          prepareWebGPU?.();
           return new MeshShading(
             shading,
             xref,

src/core/pdf_manager.js

@@ -27,6 +27,7 @@ import { JpegStream } from "./jpeg_stream.js";
 import { JpxImage } from "./jpx.js";
 import { MissingDataException } from "./core_utils.js";
 import { OperatorList } from "./operator_list.js";
+import { Pattern } from "./pattern.js";
 import { PDFDocument } from "./document.js";
 import { PDFFunctionFactory } from "./function.js";
 import { Stream } from "./stream.js";
@@ -73,19 +74,6 @@ class BasePdfManager {
     evaluatorOptions.isImageDecoderSupported &&=
       FeatureTest.isImageDecoderSupported;
 
-    // Set up a one-shot callback so evaluators can notify the main thread that
-    // WebGPU-acceleratable content was found. The flag ensures the message is
-    // sent at most once per document.
-    if (evaluatorOptions.enableWebGPU) {
-      let prepareWebGPUSent = false;
-      evaluatorOptions.prepareWebGPU = () => {
-        if (!prepareWebGPUSent) {
-          prepareWebGPUSent = true;
-          handler.send("PrepareWebGPU", null);
-        }
-      };
-    }
-    delete evaluatorOptions.enableWebGPU;
     this.evaluatorOptions = Object.freeze(evaluatorOptions);
 
     // Initialize image-options once per document.
@@ -99,6 +87,7 @@ class BasePdfManager {
     CmykICCBasedCS.setOptions(options);
     JBig2CCITTFaxWasmImage.setOptions(options);
     PDFFunctionFactory.setOptions(options);
+    Pattern.setOptions(options);
   }
 
   get docId() {

src/display/api.js

@@ -75,7 +75,7 @@ import { DOMCanvasFactory } from "./canvas_factory.js";
 import { DOMFilterFactory } from "./filter_factory.js";
 import { getNetworkStream } from "display-network_stream";
 import { GlobalWorkerOptions } from "./worker_options.js";
-import { initWebGPUMesh } from "./webgpu_mesh.js";
+import { initGPU } from "./webgpu.js";
 import { MathClamp } from "../shared/math_clamp.js";
 import { Metadata } from "./metadata.js";
 import { OptionalContentConfig } from "./optional_content_config.js";
@@ -323,6 +323,9 @@ function getDocument(src = {}) {
       : DOMBinaryDataFactory);
   const enableHWA = src.enableHWA === true;
   const enableWebGPU = src.enableWebGPU === true;
+  // Start GPU initialisation immediately so it runs in parallel with the
+  // worker bootstrap; the resolved boolean is forwarded to the worker.
+  const gpuPromise = enableWebGPU ? initGPU() : Promise.resolve(false);
   const useWasm = src.useWasm !== false;
   const pagesMapper = src.pagesMapper || new PagesMapper();
 
@@ -405,7 +408,7 @@ function getDocument(src = {}) {
       iccUrl,
       standardFontDataUrl,
       wasmUrl,
-      enableWebGPU,
+      hasGPU: false, // Set below.
     },
   };
   const transportParams = {
@@ -419,8 +422,8 @@ function getDocument(src = {}) {
     },
   };
 
-  worker.promise
-    .then(function () {
+  Promise.all([worker.promise, gpuPromise])
+    .then(function ([, hasGPU]) {
       if (task.destroyed) {
         throw new Error("Loading aborted");
       }
@@ -428,6 +431,8 @@ function getDocument(src = {}) {
         throw new Error("Worker was destroyed");
       }
 
+      docParams.evaluatorOptions.hasGPU = hasGPU;
+
       const workerIdPromise = worker.messageHandler.sendWithPromise(
         "GetDocRequest",
         docParams,
@@ -2843,13 +2848,6 @@ class WorkerTransport {
       this.#onProgress(data);
     });
 
-    messageHandler.on("PrepareWebGPU", () => {
-      if (this.destroyed) {
-        return;
-      }
-      initWebGPUMesh();
-    });
-
     if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
       messageHandler.on("FetchBinaryData", async data => {
         if (this.destroyed) {

src/display/pattern_helper.js

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { drawMeshWithGPU, isWebGPUMeshReady } from "./webgpu_mesh.js";
+import { drawMeshWithGPU, isGPUReady, loadMeshShader } from "./webgpu.js";
 import {
   FormatError,
   info,
@@ -441,6 +441,9 @@ class MeshShadingPattern extends BaseShadingPattern {
     this._bbox = IR[6];
     this._background = IR[7];
     this.matrix = null;
+    // Pre-compile the mesh pipeline now that we know GPU-renderable content
+    // is present; no-op if the GPU is not available or already compiled.
+    loadMeshShader();
   }
 
   _createMeshCanvas(combinedScale, backgroundColor, canvasFactory) {
@@ -486,7 +489,7 @@ class MeshShadingPattern extends BaseShadingPattern {
     const paddedHeight = height + BORDER_SIZE * 2;
     const tmpCanvas = canvasFactory.create(paddedWidth, paddedHeight);
 
-    if (isWebGPUMeshReady()) {
+    if (isGPUReady()) {
       tmpCanvas.context.drawImage(
         drawMeshWithGPU(
           this._figures,

src/display/webgpu.js

@@ -20,7 +20,7 @@ import { MeshFigureType } from "../shared/util.js";
 // applies the affine transform supplied via a uniform buffer to map them
 // to NDC (X: -1..1 left→right, Y: -1..1 bottom→top).
 // Colors are delivered as unorm8x4 (r,g,b,_) and passed through as-is.
-const WGSL = /* wgsl */ `
+const MESH_WGSL = /* wgsl */ `
 struct Uniforms {
   offsetX      : f32,
   offsetY      : f32,
@@ -65,12 +65,12 @@ fn fs_main(in : VertexOutput) -> @location(0) vec4<f32> {
 }
 `;
 
-class WebGPUMesh {
+class WebGPU {
   #initPromise = null;
 
   #device = null;
 
-  #pipeline = null;
+  #meshPipeline = null;
 
   // Format chosen to match the OffscreenCanvas swapchain on this device.
   #preferredFormat = null;
@@ -85,57 +85,62 @@ class WebGPUMesh {
         return false;
       }
       this.#preferredFormat = navigator.gpu.getPreferredCanvasFormat();
-      const device = (this.#device = await adapter.requestDevice());
-      const shaderModule = device.createShaderModule({ code: WGSL });
-
-      this.#pipeline = device.createRenderPipeline({
-        layout: "auto",
-        vertex: {
-          module: shaderModule,
-          entryPoint: "vs_main",
-          buffers: [
-            {
-              // Buffer 0: PDF content-space coords, 2 × float32 per vertex.
-              arrayStride: 2 * 4,
-              attributes: [
-                { shaderLocation: 0, offset: 0, format: "float32x2" },
-              ],
-            },
-            {
-              // Buffer 1: vertex colors, 4 × unorm8 per vertex (r, g, b, _).
-              arrayStride: 4,
-              attributes: [
-                { shaderLocation: 1, offset: 0, format: "unorm8x4" },
-              ],
-            },
-          ],
-        },
-        fragment: {
-          module: shaderModule,
-          entryPoint: "fs_main",
-          // Use the canvas-preferred format so the OffscreenCanvas swapchain
-          // and the pipeline output format always agree.
-          targets: [{ format: this.#preferredFormat }],
-        },
-        primitive: { topology: "triangle-list" },
-      });
-
+      this.#device = await adapter.requestDevice();
       return true;
     } catch {
       return false;
     }
   }
 
+  /**
+   * Start GPU initialization.
+   * @returns {Promise<boolean>}  true when a GPU device is available.
+   */
   init() {
-    if (this.#initPromise === null) {
-      this.#initPromise = this.#initGPU();
-    }
+    return (this.#initPromise ||= this.#initGPU());
   }
 
   get isReady() {
     return this.#device !== null;
   }
 
+  /**
+   * Compile (and cache) the Gouraud-mesh pipeline.
+   */
+  loadMeshShader() {
+    if (!this.#device || this.#meshPipeline) {
+      return;
+    }
+    const shaderModule = this.#device.createShaderModule({ code: MESH_WGSL });
+    this.#meshPipeline = this.#device.createRenderPipeline({
+      layout: "auto",
+      vertex: {
+        module: shaderModule,
+        entryPoint: "vs_main",
+        buffers: [
+          {
+            // Buffer 0: PDF content-space coords, 2 × float32 per vertex.
+            arrayStride: 2 * 4,
+            attributes: [{ shaderLocation: 0, offset: 0, format: "float32x2" }],
+          },
+          {
+            // Buffer 1: vertex colors, 4 × unorm8 per vertex (r, g, b, _).
+            arrayStride: 4,
+            attributes: [{ shaderLocation: 1, offset: 0, format: "unorm8x4" }],
+          },
+        ],
+      },
+      fragment: {
+        module: shaderModule,
+        entryPoint: "fs_main",
+        // Use the canvas-preferred format so the OffscreenCanvas swapchain
+        // and the pipeline output format always agree.
+        targets: [{ format: this.#preferredFormat }],
+      },
+      primitive: { topology: "triangle-list" },
+    });
+  }
+
   /**
    * Build flat Float32Array (positions) and Uint8Array (colors) vertex
    * streams for non-indexed triangle-list rendering.
@@ -248,6 +253,9 @@ class WebGPUMesh {
     paddedHeight,
     borderSize
   ) {
+    // Lazily compile the mesh pipeline the first time we need to draw.
+    this.loadMeshShader();
+
     const device = this.#device;
     const { offsetX, offsetY, scaleX, scaleY } = context;
     const { posData, colData, vertexCount } = this.#buildVertexStreams(
@@ -294,7 +302,7 @@ class WebGPUMesh {
     );
 
     const bindGroup = device.createBindGroup({
-      layout: this.#pipeline.getBindGroupLayout(0),
+      layout: this.#meshPipeline.getBindGroupLayout(0),
       entries: [{ binding: 0, resource: { buffer: uniformBuffer } }],
     });
 
@@ -330,7 +338,7 @@ class WebGPUMesh {
       ],
     });
     if (vertexCount > 0) {
-      renderPass.setPipeline(this.#pipeline);
+      renderPass.setPipeline(this.#meshPipeline);
       renderPass.setBindGroup(0, bindGroup);
       renderPass.setVertexBuffer(0, posBuffer);
       renderPass.setVertexBuffer(1, colBuffer);
@@ -351,14 +359,25 @@ class WebGPUMesh {
   }
 }
 
-const _webGPUMesh = new WebGPUMesh();
+const _webGPU = new WebGPU();
 
-function initWebGPUMesh() {
-  _webGPUMesh.init();
+/**
+ * Start GPU initialization as early as possible.
+ * @returns {Promise<boolean>}  true if a GPU device was acquired.
+ */
+function initGPU() {
+  return _webGPU.init();
 }
 
-function isWebGPUMeshReady() {
-  return _webGPUMesh.isReady;
+function isGPUReady() {
+  return _webGPU.isReady;
+}
+
+/**
+ * Pre-compile the Gouraud-mesh WGSL pipeline.
+ */
+function loadMeshShader() {
+  _webGPU.loadMeshShader();
 }
 
 function drawMeshWithGPU(
@@ -369,7 +388,7 @@ function drawMeshWithGPU(
   paddedHeight,
   borderSize
 ) {
-  return _webGPUMesh.draw(
+  return _webGPU.draw(
     figures,
     context,
     backgroundColor,
@@ -379,4 +398,4 @@ function drawMeshWithGPU(
   );
 }
 
-export { drawMeshWithGPU, initWebGPUMesh, isWebGPUMeshReady };
+export { drawMeshWithGPU, initGPU, isGPUReady, loadMeshShader };

test/unit/api_spec.js

@@ -197,12 +197,8 @@ describe("api", function () {
       expect(loadingTask).toBeInstanceOf(PDFDocumentLoadingTask);
       // This can be somewhat random -- we cannot guarantee perfect
       // 'Terminate' message to the worker before/after setting up pdfManager.
-      const destroyed = loadingTask._worker.promise.then(() =>
-        loadingTask.destroy()
-      );
-
-      await destroyed;
-      expect(true).toEqual(true);
+      await loadingTask._worker.promise.then(() => loadingTask.destroy());
+      await loadingTask.promise.catch(() => {});
     });
 
     it("creates pdf doc from TypedArray", async function () {