perf: warm expensive init code at snapshot time (#22714)

Slightly different approach to similar changes in #22386

Note that this doesn't use a warmup script -- we are actually just doing
more work at snapshot time.

ext/node/polyfills/02_init.js

@@ -16,7 +16,9 @@ function initialize(
   runningOnMainThread,
   workerId,
   maybeWorkerMetadata,
+  warmup = false,
 ) {
+  if (!warmup) {
     if (initialized) {
       throw Error("Node runtime already initialized");
     }
@@ -24,18 +26,6 @@ function initialize(
     if (usesLocalNodeModulesDir) {
       requireImpl.setUsesLocalNodeModulesDir();
     }
-  const nativeModuleExports = requireImpl.nativeModuleExports;
-  nodeGlobals.Buffer = nativeModuleExports["buffer"].Buffer;
-  nodeGlobals.clearImmediate = nativeModuleExports["timers"].clearImmediate;
-  nodeGlobals.clearInterval = nativeModuleExports["timers"].clearInterval;
-  nodeGlobals.clearTimeout = nativeModuleExports["timers"].clearTimeout;
-  nodeGlobals.console = nativeModuleExports["console"];
-  nodeGlobals.global = globalThis;
-  nodeGlobals.process = nativeModuleExports["process"];
-  nodeGlobals.setImmediate = nativeModuleExports["timers"].setImmediate;
-  nodeGlobals.setInterval = nativeModuleExports["timers"].setInterval;
-  nodeGlobals.setTimeout = nativeModuleExports["timers"].setTimeout;
-  nodeGlobals.performance = nativeModuleExports["perf_hooks"].performance;
 
     // FIXME(bartlomieju): not nice to depend on `Deno` namespace here
     // but it's the only way to get `args` and `version` and this point.
@@ -48,6 +38,10 @@ function initialize(
     internals.__setupChildProcessIpcChannel();
     // `Deno[Deno.internal].requireImpl` will be unreachable after this line.
     delete internals.requireImpl;
+  } else {
+    // Warm up the process module
+    internals.__bootstrapNodeProcess(undefined, undefined, undefined, true);
+  }
 }
 
 function loadCjsModule(moduleName, isMain, inspectBrk) {
@@ -63,3 +57,16 @@ internals.node = {
   initialize,
   loadCjsModule,
 };
+
+const nativeModuleExports = requireImpl.nativeModuleExports;
+nodeGlobals.Buffer = nativeModuleExports["buffer"].Buffer;
+nodeGlobals.clearImmediate = nativeModuleExports["timers"].clearImmediate;
+nodeGlobals.clearInterval = nativeModuleExports["timers"].clearInterval;
+nodeGlobals.clearTimeout = nativeModuleExports["timers"].clearTimeout;
+nodeGlobals.console = nativeModuleExports["console"];
+nodeGlobals.global = globalThis;
+nodeGlobals.process = nativeModuleExports["process"];
+nodeGlobals.setImmediate = nativeModuleExports["timers"].setImmediate;
+nodeGlobals.setInterval = nativeModuleExports["timers"].setInterval;
+nodeGlobals.setTimeout = nativeModuleExports["timers"].setTimeout;
+nodeGlobals.performance = nativeModuleExports["perf_hooks"].performance;

ext/node/polyfills/_process/streams.mjs

@@ -16,7 +16,7 @@ import * as io from "ext:deno_io/12_io.js";
 import { guessHandleType } from "ext:deno_node/internal_binding/util.ts";
 
 // https://github.com/nodejs/node/blob/00738314828074243c9a52a228ab4c68b04259ef/lib/internal/bootstrap/switches/is_main_thread.js#L41
-export function createWritableStdioStream(writer, name) {
+export function createWritableStdioStream(writer, name, warmup = false) {
   const stream = new Writable({
     emitClose: false,
     write(buf, enc, cb) {
@@ -73,7 +73,9 @@ export function createWritableStdioStream(writer, name) {
     },
   });
 
-  if (writer?.isTerminal()) {
+  // If we're warming up, create a stdout/stderr stream that assumes a terminal (the most likely case).
+  // If we're wrong at boot time, we'll recreate it.
+  if (warmup || writer?.isTerminal()) {
     // These belong on tty.WriteStream(), but the TTY streams currently have
     // following problems:
     // 1. Using them here introduces a circular dependency.
@@ -123,10 +125,11 @@ export function setReadStream(s) {
 /** https://nodejs.org/api/process.html#process_process_stdin */
 // https://github.com/nodejs/node/blob/v18.12.1/lib/internal/bootstrap/switches/is_main_thread.js#L189
 /** Create process.stdin */
-export const initStdin = () => {
+export const initStdin = (warmup = false) => {
   const fd = io.stdin ? io.STDIN_RID : undefined;
   let stdin;
-  const stdinType = _guessStdinType(fd);
+  // Warmup assumes a TTY for all stdio
+  const stdinType = warmup ? "TTY" : _guessStdinType(fd);
 
   switch (stdinType) {
     case "FILE": {
@@ -142,6 +145,11 @@ export const initStdin = () => {
       break;
     }
     case "TTY": {
+      // If it's a TTY, we know that the stdin we created during warmup is the correct one and
+      // just return null to re-use it.
+      if (!warmup) {
+        return null;
+      }
       stdin = new readStream(fd);
       break;
     }

ext/node/polyfills/process.ts

@@ -68,7 +68,7 @@ const notImplementedEvents = [
   "worker",
 ];
 
-export const argv: string[] = [];
+export const argv: string[] = ["", ""];
 let globalProcessExitCode: number | undefined = undefined;
 
 /** https://nodejs.org/api/process.html#process_process_exit_code */
@@ -868,27 +868,9 @@ function synchronizeListeners() {
   }
 }
 
-// Should be called only once, in `runtime/js/99_main.js` when the runtime is
-// bootstrapped.
-internals.__bootstrapNodeProcess = function (
-  argv0Val: string | undefined,
-  args: string[],
-  denoVersions: Record<string, string>,
-) {
-  // Overwrites the 1st item with getter.
-  if (typeof argv0Val === "string") {
-    argv0 = argv0Val;
-    Object.defineProperty(argv, "0", {
-      get: () => {
-        return argv0Val;
-      },
-    });
-  } else {
-    Object.defineProperty(argv, "0", { get: () => argv0 });
-  }
-
-  // Overwrites the 2st item with getter.
-  Object.defineProperty(argv, "1", {
+// Overwrites the 1st and 2nd items with getters.
+Object.defineProperty(argv, "0", { get: () => argv0 });
+Object.defineProperty(argv, "1", {
   get: () => {
     if (Deno.mainModule?.startsWith("file:")) {
       return pathFromURL(new URL(Deno.mainModule));
@@ -896,7 +878,19 @@ internals.__bootstrapNodeProcess = function (
       return join(Deno.cwd(), "$deno$node.js");
     }
   },
-  });
+});
+
+// Should be called only once, in `runtime/js/99_main.js` when the runtime is
+// bootstrapped.
+internals.__bootstrapNodeProcess = function (
+  argv0Val: string | undefined,
+  args: string[],
+  denoVersions: Record<string, string>,
+  warmup = false,
+) {
+  if (!warmup) {
+    argv0 = argv0Val || "";
+    // Manually concatenate these arrays to avoid triggering the getter
     for (let i = 0; i < args.length; i++) {
       argv[i + 2] = args[i];
     }
@@ -909,18 +903,28 @@ internals.__bootstrapNodeProcess = function (
     core.setMacrotaskCallback(runNextTicks);
     enableNextTick();
 
-  stdin = process.stdin = initStdin();
+    // Replace stdin if it is not a terminal
+    const newStdin = initStdin();
+    if (newStdin) {
+      stdin = process.stdin = newStdin;
+    }
+
+    // Replace stdout/stderr if they are not terminals
+    if (!io.stdout.isTerminal()) {
       /** https://nodejs.org/api/process.html#process_process_stdout */
       stdout = process.stdout = createWritableStdioStream(
         io.stdout,
         "stdout",
       );
+    }
 
+    if (!io.stderr.isTerminal()) {
       /** https://nodejs.org/api/process.html#process_process_stderr */
       stderr = process.stderr = createWritableStdioStream(
         io.stderr,
         "stderr",
       );
+    }
 
     process.setStartTime(Date.now());
 
@@ -931,6 +935,24 @@ internals.__bootstrapNodeProcess = function (
     // @ts-ignore Remove setStartTime and #startTime is not modifiable
     delete process.setStartTime;
     delete internals.__bootstrapNodeProcess;
+  } else {
+    // Warmup, assuming stdin/stdout/stderr are all terminals
+    stdin = process.stdin = initStdin(true);
+
+    /** https://nodejs.org/api/process.html#process_process_stdout */
+    stdout = process.stdout = createWritableStdioStream(
+      io.stdout,
+      "stdout",
+      true,
+    );
+
+    /** https://nodejs.org/api/process.html#process_process_stderr */
+    stderr = process.stderr = createWritableStdioStream(
+      io.stderr,
+      "stderr",
+      true,
+    );
+  }
 };
 
 export default process;

runtime/js/99_main.js

@@ -628,6 +628,28 @@ const finalDenoNs = {
   bench: () => {},
 };
 
+ObjectDefineProperties(finalDenoNs, {
+  pid: core.propGetterOnly(opPid),
+  // `ppid` should not be memoized.
+  // https://github.com/denoland/deno/issues/23004
+  ppid: core.propGetterOnly(() => op_ppid()),
+  noColor: core.propGetterOnly(() => op_bootstrap_no_color()),
+  args: core.propGetterOnly(opArgs),
+  mainModule: core.propGetterOnly(() => op_main_module()),
+  // TODO(kt3k): Remove this export at v2
+  // See https://github.com/denoland/deno/issues/9294
+  customInspect: {
+    get() {
+      warnOnDeprecatedApi(
+        "Deno.customInspect",
+        new Error().stack,
+        'Use `Symbol.for("Deno.customInspect")` instead.',
+      );
+      return customInspect;
+    },
+  },
+});
+
 const {
   denoVersion,
   tsVersion,
@@ -635,11 +657,11 @@ const {
   target,
 } = op_snapshot_options();
 
-function bootstrapMainRuntime(runtimeOptions) {
+function bootstrapMainRuntime(runtimeOptions, warmup = false) {
+  if (!warmup) {
     if (hasBootstrapped) {
       throw new Error("Worker runtime already bootstrapped");
     }
-  const nodeBootstrap = globalThis.nodeBootstrap;
 
     const {
       0: location_,
@@ -663,7 +685,6 @@ function bootstrapMainRuntime(runtimeOptions) {
     // Remove bootstrapping data from the global scope
     delete globalThis.__bootstrap;
     delete globalThis.bootstrap;
-  delete globalThis.nodeBootstrap;
     hasBootstrapped = true;
 
     // If the `--location` flag isn't set, make `globalThis.location` `undefined` and
@@ -697,14 +718,10 @@ function bootstrapMainRuntime(runtimeOptions) {
       core.wrapConsole(consoleFromDeno, core.v8Console);
     }
 
-  event.setEventTargetData(globalThis);
-  event.saveGlobalThisReference(globalThis);
-
     event.defineEventHandler(globalThis, "error");
     event.defineEventHandler(globalThis, "load");
     event.defineEventHandler(globalThis, "beforeunload");
     event.defineEventHandler(globalThis, "unload");
-  event.defineEventHandler(globalThis, "unhandledrejection");
 
     runtimeStart(
       denoVersion,
@@ -713,28 +730,6 @@ function bootstrapMainRuntime(runtimeOptions) {
       target,
     );
 
-  ObjectDefineProperties(finalDenoNs, {
-    pid: core.propGetterOnly(opPid),
-    // `ppid` should not be memoized.
-    // https://github.com/denoland/deno/issues/23004
-    ppid: core.propGetterOnly(() => op_ppid()),
-    noColor: core.propGetterOnly(() => op_bootstrap_no_color()),
-    args: core.propGetterOnly(opArgs),
-    mainModule: core.propGetterOnly(() => op_main_module()),
-    // TODO(kt3k): Remove this export at v2
-    // See https://github.com/denoland/deno/issues/9294
-    customInspect: {
-      get() {
-        warnOnDeprecatedApi(
-          "Deno.customInspect",
-          new Error().stack,
-          'Use `Symbol.for("Deno.customInspect")` instead.',
-        );
-        return customInspect;
-      },
-    },
-  });
-
     // TODO(bartlomieju): deprecate --unstable
     if (unstableFlag) {
       ObjectAssign(finalDenoNs, denoNsUnstable);
@@ -781,10 +776,12 @@ function bootstrapMainRuntime(runtimeOptions) {
     if (nodeBootstrap) {
       nodeBootstrap(hasNodeModulesDir, argv0, /* runningOnMainThread */ true);
     }
-
     if (future) {
       delete globalThis.window;
     }
+  } else {
+    // Warmup
+  }
 }
 
 function bootstrapWorkerRuntime(
@@ -793,13 +790,13 @@ function bootstrapWorkerRuntime(
   internalName,
   workerId,
   maybeWorkerMetadata,
+  warmup = false,
 ) {
+  if (!warmup) {
     if (hasBootstrapped) {
       throw new Error("Worker runtime already bootstrapped");
     }
 
-  const nodeBootstrap = globalThis.nodeBootstrap;
-
     const {
       0: location_,
       1: unstableFlag,
@@ -817,12 +814,9 @@ function bootstrapWorkerRuntime(
     performance.setTimeOrigin(DateNow());
     globalThis_ = globalThis;
 
-  removeImportedOps();
-
     // Remove bootstrapping data from the global scope
     delete globalThis.__bootstrap;
     delete globalThis.bootstrap;
-  delete globalThis.nodeBootstrap;
     hasBootstrapped = true;
 
     exposeUnstableFeaturesForWindowOrWorkerGlobalScope({
@@ -848,12 +842,8 @@ function bootstrapWorkerRuntime(
     const consoleFromDeno = globalThis.console;
     core.wrapConsole(consoleFromDeno, core.v8Console);
 
-  event.setEventTargetData(globalThis);
-  event.saveGlobalThisReference(globalThis);
-
     event.defineEventHandler(self, "message");
     event.defineEventHandler(self, "error", undefined, true);
-  event.defineEventHandler(self, "unhandledrejection");
 
     // `Deno.exit()` is an alias to `self.close()`. Setting and exit
     // code using an op in worker context is a no-op.
@@ -884,6 +874,9 @@ function bootstrapWorkerRuntime(
       }
     }
 
+    // Not available in workers
+    delete finalDenoNs.mainModule;
+
     if (!ArrayPrototypeIncludes(unstableFeatures, unstableIds.unsafeProto)) {
       // Removes the `__proto__` for security reasons.
       // https://tc39.es/ecma262/#sec-get-object.prototype.__proto__
@@ -896,25 +889,8 @@ function bootstrapWorkerRuntime(
       delete globalThis.Date.prototype.toTemporalInstant;
     }
 
-  ObjectDefineProperties(finalDenoNs, {
-    pid: core.propGetterOnly(opPid),
-    noColor: core.propGetterOnly(() => op_bootstrap_no_color()),
-    args: core.propGetterOnly(opArgs),
-    // TODO(kt3k): Remove this export at v2
-    // See https://github.com/denoland/deno/issues/9294
-    customInspect: {
-      get() {
-        warnOnDeprecatedApi(
-          "Deno.customInspect",
-          new Error().stack,
-          'Use `Symbol.for("Deno.customInspect")` instead.',
-        );
-        return customInspect;
-      },
-    },
-  });
-  // Setup `Deno` global - we're actually overriding already
-  // existing global `Deno` with `Deno` namespace from "./deno.ts".
+    // Setup `Deno` global - we're actually overriding already existing global
+    // `Deno` with `Deno` namespace from "./deno.ts".
     ObjectDefineProperty(globalThis, "Deno", core.propReadOnly(finalDenoNs));
 
     const workerMetadata = maybeWorkerMetadata
@@ -930,9 +906,37 @@ function bootstrapWorkerRuntime(
         workerMetadata,
       );
     }
+  } else {
+    // Warmup
+    return;
+  }
 }
 
+const nodeBootstrap = globalThis.nodeBootstrap;
+delete globalThis.nodeBootstrap;
+
 globalThis.bootstrap = {
   mainRuntime: bootstrapMainRuntime,
   workerRuntime: bootstrapWorkerRuntime,
 };
+
+event.setEventTargetData(globalThis);
+event.saveGlobalThisReference(globalThis);
+event.defineEventHandler(globalThis, "unhandledrejection");
+
+// Nothing listens to this, but it warms up the code paths for event dispatch
+(new event.EventTarget()).dispatchEvent(new Event("warmup"));
+
+removeImportedOps();
+
+// Run the warmup path through node and runtime/worker bootstrap functions
+bootstrapMainRuntime(undefined, true);
+bootstrapWorkerRuntime(
+  undefined,
+  undefined,
+  undefined,
+  undefined,
+  undefined,
+  true,
+);
+nodeBootstrap(undefined, undefined, undefined, undefined, undefined, true);