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.

3 files changed, 120 insertions, 83 deletions

diff --git a/ext/node/polyfills/02_init.js b/ext/node/polyfills/02_init.js
index 85f924493..752f518bf 100644
--- a/ext/node/polyfills/02_init.js
+++ b/ext/node/polyfills/02_init.js
@@ -16,38 +16,32 @@ function initialize(
   runningOnMainThread,
   workerId,
   maybeWorkerMetadata,
+  warmup = false,
 ) {
-  if (initialized) {
-    throw Error("Node runtime already initialized");
-  }
-  initialized = true;
-  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;
+  if (!warmup) {
+    if (initialized) {
+      throw Error("Node runtime already initialized");
+    }
+    initialized = true;
+    if (usesLocalNodeModulesDir) {
+      requireImpl.setUsesLocalNodeModulesDir();
+    }
 
-  // FIXME(bartlomieju): not nice to depend on `Deno` namespace here
-  // but it's the only way to get `args` and `version` and this point.
-  internals.__bootstrapNodeProcess(argv0, Deno.args, Deno.version);
-  internals.__initWorkerThreads(
-    runningOnMainThread,
-    workerId,
-    maybeWorkerMetadata,
-  );
-  internals.__setupChildProcessIpcChannel();
-  // `Deno[Deno.internal].requireImpl` will be unreachable after this line.
-  delete internals.requireImpl;
+    // FIXME(bartlomieju): not nice to depend on `Deno` namespace here
+    // but it's the only way to get `args` and `version` and this point.
+    internals.__bootstrapNodeProcess(argv0, Deno.args, Deno.version);
+    internals.__initWorkerThreads(
+      runningOnMainThread,
+      workerId,
+      maybeWorkerMetadata,
+    );
+    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;
diff --git a/ext/node/polyfills/_process/streams.mjs b/ext/node/polyfills/_process/streams.mjs
index 09c53eb9a..f50e20588 100644
--- a/ext/node/polyfills/_process/streams.mjs
+++ b/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;
     }
diff --git a/ext/node/polyfills/process.ts b/ext/node/polyfills/process.ts
index 44207e2f4..70c516c96 100644
--- a/ext/node/polyfills/process.ts
+++ b/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 */
@@ -868,69 +868,91 @@ function synchronizeListeners() {
   }
 }
 
+// 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));
+    } else {
+      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,
 ) {
-  // 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 });
-  }
+  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];
+    }
 
-  // Overwrites the 2st item with getter.
-  Object.defineProperty(argv, "1", {
-    get: () => {
-      if (Deno.mainModule?.startsWith("file:")) {
-        return pathFromURL(new URL(Deno.mainModule));
-      } else {
-        return join(Deno.cwd(), "$deno$node.js");
-      }
-    },
-  });
-  for (let i = 0; i < args.length; i++) {
-    argv[i + 2] = args[i];
-  }
+    for (const [key, value] of Object.entries(denoVersions)) {
+      versions[key] = value;
+    }
 
-  for (const [key, value] of Object.entries(denoVersions)) {
-    versions[key] = value;
-  }
+    core.setNextTickCallback(processTicksAndRejections);
+    core.setMacrotaskCallback(runNextTicks);
+    enableNextTick();
 
-  core.setNextTickCallback(processTicksAndRejections);
-  core.setMacrotaskCallback(runNextTicks);
-  enableNextTick();
+    // Replace stdin if it is not a terminal
+    const newStdin = initStdin();
+    if (newStdin) {
+      stdin = process.stdin = newStdin;
+    }
 
-  stdin = process.stdin = initStdin();
-  /** https://nodejs.org/api/process.html#process_process_stdout */
-  stdout = process.stdout = createWritableStdioStream(
-    io.stdout,
-    "stdout",
-  );
+    // 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",
+      );
+    }
 
-  /** https://nodejs.org/api/process.html#process_process_stderr */
-  stderr = process.stderr = createWritableStdioStream(
-    io.stderr,
-    "stderr",
-  );
+    if (!io.stderr.isTerminal()) {
+      /** https://nodejs.org/api/process.html#process_process_stderr */
+      stderr = process.stderr = createWritableStdioStream(
+        io.stderr,
+        "stderr",
+      );
+    }
 
-  process.setStartTime(Date.now());
+    process.setStartTime(Date.now());
 
-  arch = arch_();
-  platform = isWindows ? "win32" : Deno.build.os;
-  pid = Deno.pid;
+    arch = arch_();
+    platform = isWindows ? "win32" : Deno.build.os;
+    pid = Deno.pid;
 
-  // @ts-ignore Remove setStartTime and #startTime is not modifiable
-  delete process.setStartTime;
-  delete internals.__bootstrapNodeProcess;
+    // @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;