[browser][MT] pre-load threads early in dotnet.js

src/mono/browser/build/BrowserWasmApp.targets

@@ -121,7 +121,8 @@
 
     <PropertyGroup>
       <!-- TODO: set this from some user-facing property?  -1 means use the default baked into dotnet.native.js -->
-      <_WasmPThreadPoolSize Condition="'$(_WasmPThreadPoolSize)' == ''">-1</_WasmPThreadPoolSize>
+      <_WasmPThreadPoolInitialSize Condition="'$(_WasmPThreadPoolInitialSize)' == ''">-1</_WasmPThreadPoolInitialSize>
+      <_WasmPThreadPoolUnusedSize Condition="'$(_WasmPThreadPoolUnusedSize)' == ''">-1</_WasmPThreadPoolUnusedSize>
     </PropertyGroup>
 
     <ItemGroup>
@@ -148,7 +149,8 @@
       NativeAssets="@(WasmNativeAsset)"
       DebugLevel="$(WasmDebugLevel)"
       IncludeThreadsWorker="$(WasmEnableThreads)"
-      PThreadPoolSize="$(_WasmPThreadPoolSize)"
+      PThreadPoolInitialSize="$(_WasmPThreadPoolInitialSize)"
+      PThreadPoolUnusedSize="$(_WasmPThreadPoolUnusedSize)"
       UseWebcil="$(WasmEnableWebcil)"
       WasmIncludeFullIcuData="$(WasmIncludeFullIcuData)"
       WasmIcuDataFileName="$(WasmIcuDataFileName)"

src/mono/browser/runtime/diagnostics/browser/controller.ts

@@ -7,7 +7,7 @@ import { threads_c_functions as cwraps } from "../../cwraps";
 import { INTERNAL, mono_assert } from "../../globals";
 import { mono_log_info, mono_log_debug, mono_log_warn } from "../../logging";
 import { withStackAlloc, getI32 } from "../../memory";
-import { waitForThread } from "../../pthreads/browser";
+import { waitForThread } from "../../pthreads";
 import { isDiagnosticMessage, makeDiagnosticServerControlCommand } from "../shared/controller-commands";
 import monoDiagnosticsMock from "consts:monoDiagnosticsMock";
 import { PThreadPtr, Thread } from "../../types/internal";

src/mono/browser/runtime/diagnostics/mock/environment.ts

@@ -6,7 +6,7 @@ import type { FilterPredicate, MockEnvironment } from "./types";
 import Serializer from "../server_pthread/ipc-protocol/base-serializer";
 import { CommandSetId, EventPipeCommandId, ProcessCommandId } from "../server_pthread/ipc-protocol/types";
 import { assertNever } from "../../types/internal";
-import { pthread_self } from "../../pthreads/worker";
+import { pthread_self } from "../../pthreads";
 import { createPromiseController, mono_assert } from "../../globals";
 
 

src/mono/browser/runtime/diagnostics/server_pthread/index.ts

@@ -6,7 +6,7 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import monoDiagnosticsMock from "consts:monoDiagnosticsMock";
 
 import { PromiseAndController, assertNever } from "../../types/internal";
-import { pthread_self } from "../../pthreads/worker";
+import { pthread_self } from "../../pthreads";
 import { createPromiseController, mono_assert } from "../../globals";
 import { threads_c_functions as cwraps } from "../../cwraps";
 import { EventPipeSessionIDImpl } from "../shared/types";

src/mono/browser/runtime/diagnostics/shared/controller-commands.ts

@@ -1,7 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-import { isMonoThreadMessage } from "../../pthreads/shared";
+import { isMonoThreadMessage } from "../../pthreads";
 import type { MonoThreadMessage } from "../../types/internal";
 
 // Messages from the main thread to the diagnostic server thread

src/mono/browser/runtime/dotnet.d.ts

@@ -189,11 +189,15 @@ type MonoConfig = {
     /**
      * initial number of workers to add to the emscripten pthread pool
      */
-    pthreadPoolSize?: number;
+    pthreadPoolInitialSize?: number;
     /**
-     * initial number of unused workers keep in the emscripten pthread pool after startup
+     * number of unused workers kept in the emscripten pthread pool after startup
      */
-    pthreadPoolReady?: number;
+    pthreadPoolUnusedSize?: number;
+    /**
+     * Delay in milliseconds before starting the finalizer thread
+     */
+    finalizerThreadStartDelayMs?: number;
     /**
      * If true, a list of the methods optimized by the interpreter will be saved and used for faster startup
      *  on future runs of the application

src/mono/browser/runtime/exports-binding.ts

@@ -10,8 +10,7 @@ import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js }
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
-import { mono_wasm_eventloop_has_unsettled_interop_promises } from "./pthreads/shared/eventloop";
-import { mono_wasm_pthread_on_pthread_attached, mono_wasm_pthread_on_pthread_unregistered, mono_wasm_pthread_on_pthread_registered, mono_wasm_pthread_set_name } from "./pthreads/worker";
+import { mono_wasm_eventloop_has_unsettled_interop_promises } from "./pthreads";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_wasm_diagnostic_server_on_server_thread_created } from "./diagnostics/server_pthread";
@@ -22,13 +21,15 @@ import { mono_wasm_profiler_leave, mono_wasm_profiler_enter } from "./profiler";
 import { mono_wasm_change_case, mono_wasm_change_case_invariant } from "./hybrid-globalization/change-case";
 import { mono_wasm_compare_string, mono_wasm_ends_with, mono_wasm_starts_with, mono_wasm_index_of } from "./hybrid-globalization/collations";
 import { mono_wasm_get_calendar_info } from "./hybrid-globalization/calendar";
-import { mono_wasm_install_js_worker_interop, mono_wasm_uninstall_js_worker_interop } from "./pthreads/shared";
 
 import { mono_wasm_get_culture_info } from "./hybrid-globalization/culture-info";
 import { mono_wasm_get_first_day_of_week, mono_wasm_get_first_week_of_year } from "./hybrid-globalization/locales";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
+import { mono_wasm_pthread_on_pthread_attached, mono_wasm_pthread_on_pthread_unregistered, mono_wasm_pthread_on_pthread_registered, mono_wasm_pthread_set_name } from "./pthreads";
+import { mono_wasm_install_js_worker_interop, mono_wasm_uninstall_js_worker_interop } from "./pthreads";
+
 // the JS methods would be visible to EMCC linker and become imports of the WASM module
 
 export const mono_wasm_threads_imports = !WasmEnableThreads ? [] : [

src/mono/browser/runtime/exports-internal.ts

@@ -23,7 +23,7 @@ import { mono_wasm_get_func_id_to_name_mappings } from "./logging";
 import { monoStringToStringUnsafe } from "./strings";
 import { mono_wasm_bind_cs_function } from "./invoke-cs";
 
-import { dumpThreads, thread_available } from "./pthreads/browser";
+import { dumpThreads, thread_available } from "./pthreads";
 
 export function export_internal(): any {
     return {

src/mono/browser/runtime/exports.ts

@@ -22,7 +22,7 @@ import { mono_wasm_stringify_as_error_with_stack } from "./logging";
 import { instantiate_asset, instantiate_symbols_asset, instantiate_segmentation_rules_asset } from "./assets";
 import { jiterpreter_dump_stats } from "./jiterpreter";
 import { forceDisposeProxies } from "./gc-handles";
-import { dumpThreads } from "./pthreads/browser";
+import { dumpThreads } from "./pthreads";
 
 export let runtimeList: RuntimeList;
 
@@ -70,10 +70,6 @@ function initializeExports(globalObjects: GlobalObjects): RuntimeAPI {
         runtimeList = globalThisAny.getDotnetRuntime.__list;
     }
 
-    if (BuildConfiguration === "Debug") {
-        globalThisAny.INTERNAL = globals.internal;
-    }
-
     return exportedRuntimeAPI;
 }
 

src/mono/browser/runtime/interp-pgo.ts

@@ -197,8 +197,9 @@ export async function getCacheKey(prefix: string): Promise<string | null> {
     delete inputs.interopCleanupOnExit;
     delete inputs.dumpThreadsOnNonZeroExit;
     delete inputs.logExitCode;
-    delete inputs.pthreadPoolSize;
-    delete inputs.pthreadPoolReady;
+    delete inputs.pthreadPoolInitialSize;
+    delete inputs.pthreadPoolUnusedSize;
+    delete inputs.finalizerThreadStartDelayMs;
     delete inputs.asyncFlushOnExit;
     delete inputs.remoteSources;
     delete inputs.ignorePdbLoadErrors;

src/mono/browser/runtime/loader/assets.ts

@@ -20,6 +20,8 @@ let parallel_count = 0;
 const assetsToLoad: AssetEntryInternal[] = [];
 const singleAssets: Map<string, AssetEntryInternal> = new Map();
 
+const worker_empty_prefix = "          -    ";
+
 const jsRuntimeModulesAssetTypes: {
     [k: string]: boolean
 } = {
@@ -738,7 +740,7 @@ export async function streamingCompileWasm() {
 export function preloadWorkers() {
     if (!WasmEnableThreads) return;
     const jsModuleWorker = resolve_single_asset_path("js-module-threads");
-    for (let i = 0; i < loaderHelpers.config.pthreadPoolSize!; i++) {
+    for (let i = 0; i < loaderHelpers.config.pthreadPoolInitialSize!; i++) {
         const workerNumber = loaderHelpers.workerNextNumber++;
         const worker: Partial<PThreadWorker> = new Worker(jsModuleWorker.resolvedUrl!, {
             name: "dotnet-worker-" + workerNumber.toString().padStart(3, "0"),
@@ -748,9 +750,9 @@ export function preloadWorkers() {
             pthreadId: PThreadPtrNull,
             reuseCount: 0,
             updateCount: 0,
-            threadPrefix: "          -    ",
+            threadPrefix: worker_empty_prefix,
             threadName: "emscripten-pool",
         } as any;
         loaderHelpers.loadingWorkers.push(worker as any);
     }
-}
+}

src/mono/browser/runtime/loader/config.ts

@@ -188,11 +188,14 @@ export function normalizeConfig() {
     }
 
     // ActiveIssue https://github.com/dotnet/runtime/issues/75602
-    if (WasmEnableThreads && !Number.isInteger(config.pthreadPoolSize)) {
-        config.pthreadPoolSize = 7;
+    if (WasmEnableThreads && !Number.isInteger(config.pthreadPoolInitialSize)) {
+        config.pthreadPoolInitialSize = 7;
     }
-    if (WasmEnableThreads && !Number.isInteger(config.pthreadPoolReady)) {
-        config.pthreadPoolReady = 3;
+    if (WasmEnableThreads && !Number.isInteger(config.pthreadPoolUnusedSize)) {
+        config.pthreadPoolUnusedSize = 3;
+    }
+    if (WasmEnableThreads && !Number.isInteger(config.finalizerThreadStartDelayMs)) {
+        config.finalizerThreadStartDelayMs = 200;
     }
 
     // this is how long the Mono GC will try to wait for all threads to be suspended before it gives up and aborts the process

src/mono/browser/runtime/managed-exports.ts

@@ -11,7 +11,7 @@ import { marshal_array_to_cs, marshal_array_to_cs_impl, marshal_bool_to_cs, mars
 import { marshal_int32_to_js, end_marshal_task_to_js, marshal_string_to_js, begin_marshal_task_to_js, marshal_exception_to_js } from "./marshal-to-js";
 import { do_not_force_dispose } from "./gc-handles";
 import { assert_c_interop, assert_js_interop } from "./invoke-js";
-import { mono_wasm_main_thread_ptr } from "./pthreads/shared";
+import { mono_wasm_main_thread_ptr } from "./pthreads";
 import { _zero_region } from "./memory";
 import { stringToUTF8Ptr } from "./strings";
 

src/mono/browser/runtime/marshal-to-cs.ts

@@ -22,7 +22,7 @@ import { _zero_region, forceThreadMemoryViewRefresh, localHeapViewF64, localHeap
 import { stringToMonoStringRoot, stringToUTF16 } from "./strings";
 import { JSMarshalerArgument, JSMarshalerArguments, JSMarshalerType, MarshalerToCs, MarshalerToJs, BoundMarshalerToCs, MarshalerType } from "./types/internal";
 import { TypedArray } from "./types/emscripten";
-import { addUnsettledPromise, settleUnsettledPromise } from "./pthreads/shared/eventloop";
+import { addUnsettledPromise, settleUnsettledPromise } from "./pthreads";
 import { mono_log_debug } from "./logging";
 import { complete_task } from "./managed-exports";
 import { gc_locked } from "./gc-lock";

src/mono/browser/runtime/polyfills.ts

@@ -5,8 +5,8 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import type { EmscriptenReplacements } from "./types/internal";
 import type { TypedArray } from "./types/emscripten";
 import { ENVIRONMENT_IS_NODE, ENVIRONMENT_IS_WORKER, INTERNAL, Module, loaderHelpers, runtimeHelpers } from "./globals";
-import { replaceEmscriptenPThreadUI } from "./pthreads/browser/replacements";
-import { replaceEmscriptenPThreadWorker } from "./pthreads/worker/replacements";
+import { replaceEmscriptenPThreadWorker } from "./pthreads";
+import { replaceEmscriptenPThreadUI } from "./pthreads";
 
 const dummyPerformance = {
     now: function () {

src/mono/browser/runtime/pthreads/README.md

@@ -17,11 +17,11 @@ On the other hand, pthreads in native code have a peer relationship: any two thr
 
 ## Main thread API
 
-In the main thread, `pthreads/browser` provides a `getThread` function that returns a `{ pthread_ptr: pthread_ptr, worker: Worker, port: MessagePort }` object that can be used to communicate with the worker thread.
+In the main thread, `pthreads/ui-thread` provides a `getThread` function that returns a `{ pthread_ptr: pthread_ptr, worker: Worker, port: MessagePort }` object that can be used to communicate with the worker thread.
 
 ## Worker thread API
 
-In the worker threads, `pthread/worker` provides `currentWorkerThreadEvents` which is an [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget) that fires `'dotnet:pthread:created'` and `'dotnet:pthread:attached'` events when a pthread is started on the worker, and when that pthread attaches to the Mono runtime. A good place to add event listeners is in `mono_wasm_pthread_worker_init` in `startup.ts`.
+In the worker threads, `pthread/worker-*` provides `currentWorkerThreadEvents` which is an [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget) that fires `'dotnet:pthread:created'` and `'dotnet:pthread:attached'` events when a pthread is started on the worker, and when that pthread attaches to the Mono runtime. A good place to add event listeners is in `mono_wasm_pthread_worker_init` in `startup.ts`.
 The events have a `portToMain` property which is a dotnet-specific `MessagePort` for posting messages to the main thread and for listening for messages from the main thread.
 
 ## Implementation