[browser][MT] dump JS threads when GC deadlock (dotnet#98843)

src/mono/browser/runtime/debug.ts

@@ -1,8 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-import BuildConfiguration from "consts:configuration";
-
 import { INTERNAL, Module, loaderHelpers, runtimeHelpers } from "./globals";
 import { toBase64StringImpl } from "./base64";
 import cwraps from "./cwraps";
@@ -364,11 +362,6 @@ export function mono_wasm_debugger_log(level: number, message_ptr: CharPtr): voi
  INTERNAL.logging.debugger(level, message);
  return;
  }
-
- if (BuildConfiguration === "Debug") {
- // eslint-disable-next-line no-console
- console.debug(`Debugger.Debug: ${message}`);
- }
 }
 
 type CallDetails = {

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

@@ -31,6 +31,7 @@ import {
  mono_wasm_pthread_on_pthread_attached, mono_wasm_pthread_on_pthread_unregistered,
  mono_wasm_pthread_on_pthread_registered, mono_wasm_pthread_set_name, mono_wasm_install_js_worker_interop, mono_wasm_uninstall_js_worker_interop
 } from "./pthreads";
+import { mono_wasm_dump_threads } from "./pthreads/ui-thread";
 
 
 // the JS methods would be visible to EMCC linker and become imports of the WASM module
@@ -45,6 +46,8 @@ export const mono_wasm_threads_imports = !WasmEnableThreads ? [] : [
 
  // threads.c
  mono_wasm_eventloop_has_unsettled_interop_promises,
+ // mono-threads.c
+ mono_wasm_dump_threads,
  // diagnostics_server.c
  mono_wasm_diagnostic_server_on_server_thread_created,
  mono_wasm_diagnostic_server_on_runtime_server_init,

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

@@ -23,14 +23,14 @@ 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";
+import { mono_wasm_dump_threads, thread_available } from "./pthreads";
 
 export function export_internal(): any {
  return {
  // tests
  mono_wasm_exit: (exit_code: number) => { Module.err("early exit " + exit_code); },
  forceDisposeProxies,
- dumpThreads: WasmEnableThreads ? dumpThreads : undefined,
+ mono_wasm_dump_threads: WasmEnableThreads ? mono_wasm_dump_threads : undefined,
 
  // with mono_wasm_debugger_log and mono_wasm_trace_logger
  logging: undefined,

src/mono/browser/runtime/exports.ts

@@ -10,7 +10,7 @@ import WasmEnableExceptionHandling from "consts:wasmEnableExceptionHandling";
 import type { RuntimeAPI } from "./types";
 
 import { Module, exportedRuntimeAPI, loaderHelpers, passEmscriptenInternals, runtimeHelpers, setRuntimeGlobals, } from "./globals";
-import { GlobalObjects } from "./types/internal";
+import { GlobalObjects, RuntimeHelpers } from "./types/internal";
 import { configureEmscriptenStartup, configureRuntimeStartup, configureWorkerStartup } from "./startup";
 
 import { create_weak_ref } from "./weak-ref";
@@ -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";
+import { mono_wasm_dump_threads } from "./pthreads";
 
 export let runtimeList: RuntimeList;
 
@@ -32,19 +32,19 @@ function initializeExports(globalObjects: GlobalObjects): RuntimeAPI {
  const globalThisAny = globalThis as any;
 
  Object.assign(globals.internal, export_internal());
- Object.assign(runtimeHelpers, {
+ const rh: Partial<RuntimeHelpers> = {
  stringify_as_error_with_stack: mono_wasm_stringify_as_error_with_stack,
  instantiate_symbols_asset,
  instantiate_asset,
  jiterpreter_dump_stats,
  forceDisposeProxies,
  instantiate_segmentation_rules_asset,
- });
+
+ };
  if (WasmEnableThreads) {
- Object.assign(runtimeHelpers, {
- dumpThreads,
- });
+ rh.dumpThreads = mono_wasm_dump_threads;
  }
+ Object.assign(runtimeHelpers, rh);
 
  const API = export_api();
  Object.assign(exportedRuntimeAPI, {

src/mono/browser/runtime/jiterpreter.ts

@@ -891,7 +891,7 @@ function generate_wasm(
  // suites or benchmarks if you've enabled stats
  const tracesCompiled = getCounter(JiterpCounter.TracesCompiled);
  if (builder.options.enableStats && tracesCompiled && (tracesCompiled % autoDumpInterval) === 0)
- jiterpreter_dump_stats(false, true);
+ jiterpreter_dump_stats(true);
 
  return idx;
  } catch (exc: any) {
@@ -1074,14 +1074,14 @@ export function mono_jiterp_free_method_data_js(
  mono_jiterp_free_method_data_jit_call(method);
 }
 
-export function jiterpreter_dump_stats(b?: boolean, concise?: boolean) {
+export function jiterpreter_dump_stats(concise?: boolean): void {
  if (!runtimeHelpers.runtimeReady) {
  return;
  }
- if (!mostRecentOptions || (b !== undefined))
+ if (!mostRecentOptions)
  mostRecentOptions = getOptions();
 
- if (!mostRecentOptions.enableStats && (b !== undefined))
+ if (!mostRecentOptions.enableStats)
  return;
 
  const backBranchesEmitted = getCounter(JiterpCounter.BackBranchesEmitted),
@@ -1243,10 +1243,4 @@ export function jiterpreter_dump_stats(b?: boolean, concise?: boolean) {
 
  for (const k in simdFallbackCounters)
  mono_log_info(`// simd ${k}: ${simdFallbackCounters[k]} fallback insn(s)`);
-
- if ((typeof (globalThis.setTimeout) === "function") && (b !== undefined))
- setTimeout(
- () => jiterpreter_dump_stats(b),
- 15000
- );
 }

src/mono/browser/runtime/pthreads/index.ts

@@ -6,7 +6,7 @@ export {
  mono_wasm_pthread_ptr, update_thread_info, isMonoThreadMessage, monoThreadInfo,
 } from "./shared";
 export {
- dumpThreads, thread_available, cancelThreads, is_thread_available,
+ mono_wasm_dump_threads, thread_available, cancelThreads, is_thread_available,
  populateEmscriptenPool, mono_wasm_init_threads, init_finalizer_thread,
  waitForThread, replaceEmscriptenPThreadUI
 } from "./ui-thread";

src/mono/browser/runtime/pthreads/ui-thread.ts

@@ -182,7 +182,7 @@ export function cancelThreads() {
  }
 }
 
-export function dumpThreads(): void {
+export function mono_wasm_dump_threads(): void {
  if (!WasmEnableThreads) return;
  mono_log_info("Dumping web worker info as seen by UI thread, it could be stale: ");
  const emptyInfo: PThreadInfo = {
@@ -278,7 +278,7 @@ export function replaceEmscriptenPThreadUI(modulePThread: PThreadLibrary): void
  }
  };
  if (BuildConfiguration === "Debug") {
- (globalThis as any).dumpThreads = dumpThreads;
+ (globalThis as any).dumpThreads = mono_wasm_dump_threads;
  (globalThis as any).getModulePThread = getModulePThread;
  }
 }

src/mono/browser/runtime/types/internal.ts

@@ -235,7 +235,7 @@ export type RuntimeHelpers = {
  instantiate_asset: (asset: AssetEntry, url: string, bytes: Uint8Array) => void,
  instantiate_symbols_asset: (pendingAsset: AssetEntryInternal) => Promise<void>,
  instantiate_segmentation_rules_asset: (pendingAsset: AssetEntryInternal) => Promise<void>,
- jiterpreter_dump_stats?: (x: boolean) => string,
+ jiterpreter_dump_stats?: (concise?: boolean) => void,
  forceDisposeProxies: (disposeMethods: boolean, verbose: boolean) => void,
  dumpThreads: () => void,
 }

src/mono/mono/utils/mono-threads-wasm.c

@@ -541,9 +541,15 @@ mono_threads_wasm_on_thread_registered (void)
 }
 
 #ifndef DISABLE_THREADS
+static pthread_t deputy_thread_tid;
 extern void mono_wasm_start_deputy_thread_async (void);
 extern void mono_wasm_trace_logger (const char *log_domain, const char *log_level, const char *message, mono_bool fatal, void *user_data);
-static pthread_t deputy_thread_tid;
+extern void mono_wasm_dump_threads (void);
+
+void mono_wasm_dump_threads_async (void)
+{
+ mono_threads_wasm_async_run_in_target_thread (mono_threads_wasm_ui_thread_tid (), mono_wasm_dump_threads);
+}
 
 gboolean
 mono_threads_wasm_is_deputy_thread (void)

src/mono/mono/utils/mono-threads-wasm.h

@@ -28,6 +28,9 @@ mono_threads_wasm_ui_thread_tid (void);
 
 #ifndef DISABLE_THREADS
 
+void 
+mono_wasm_dump_threads_async (void);
+
 gboolean
 mono_threads_wasm_is_deputy_thread (void);
 

src/mono/mono/utils/mono-threads.c

@@ -281,6 +281,12 @@ mono_threads_end_global_suspend (void)
 static void
 dump_threads (void)
 {
+#ifdef HOST_BROWSER
+#ifndef DISABLE_THREADS
+ mono_wasm_dump_threads_async ();
+#endif
+#endif
+
  MonoThreadInfo *cur = mono_thread_info_current ();
 
  g_async_safe_printf ("STATE CUE CARD: (? means a positive number, usually 1 or 2, * means any number)\n");