build: speed up startup with V8 code cache

Makefile

@@ -91,6 +91,22 @@ $(NODE_G_EXE): config.gypi out/Makefile
 	$(MAKE) -C out BUILDTYPE=Debug V=$(V)
 	if [ ! -r $@ -o ! -L $@ ]; then ln -fs out/Debug/$(NODE_EXE) $@; fi
 
+CODE_CACHE_DIR ?= out/$(BUILDTYPE)/obj/gen
+CODE_CACHE_FILE ?= $(CODE_CACHE_DIR)/node_code_cache.cc
+
+.PHONY: with-code-cache
+with-code-cache:
+	$(PYTHON) ./configure
+	$(MAKE)
+	mkdir -p $(CODE_CACHE_DIR)
+	out/$(BUILDTYPE)/$(NODE_EXE) --expose-internals tools/generate_code_cache.js $(CODE_CACHE_FILE)
+	$(PYTHON) ./configure --code-cache-path $(CODE_CACHE_FILE)
+	$(MAKE)
+
+.PHONY: test-code-cache
+test-code-cache: with-code-cache
+	$(PYTHON) tools/test.py $(PARALLEL_ARGS) --mode=$(BUILDTYPE_LOWER) code-cache
+
 out/Makefile: common.gypi deps/uv/uv.gyp deps/http_parser/http_parser.gyp \
               deps/zlib/zlib.gyp deps/v8/gypfiles/toolchain.gypi \
               deps/v8/gypfiles/features.gypi deps/v8/gypfiles/v8.gyp node.gyp \

configure

@@ -486,6 +486,12 @@ parser.add_option('--without-snapshot',
     dest='without_snapshot',
     help=optparse.SUPPRESS_HELP)
 
+parser.add_option('--code-cache-path',
+    action='store',
+    dest='code_cache_path',
+    help='Use a file generated by tools/generate_code_cache.js to compile the'
+         ' code cache for builtin modules into the binary')
+
 parser.add_option('--without-ssl',
     action='store_true',
     dest='without_ssl',
@@ -974,6 +980,8 @@ def configure_node(o):
     o['variables']['debug_nghttp2'] = 'false'
 
   o['variables']['node_no_browser_globals'] = b(options.no_browser_globals)
+  if options.code_cache_path:
+    o['variables']['node_code_cache_path'] = options.code_cache_path
   o['variables']['node_shared'] = b(options.shared)
   node_module_version = getmoduleversion.get_version()
 

lib/internal/bootstrap/cache.js

@@ -0,0 +1,30 @@
+'use strict';
+
+// This is only exposed for internal build steps and testing purposes.
+// We create new copies of the source and the code cache
+// so the resources eventually used to compile builtin modules
+// cannot be tampered with even with --expose-internals
+
+const {
+  NativeModule, internalBinding
+} = require('internal/bootstrap/loaders');
+
+module.exports = {
+  builtinSource: Object.assign({}, NativeModule._source),
+  codeCache: internalBinding('code_cache'),
+  compiledWithoutCache: NativeModule.compiledWithoutCache,
+  compiledWithCache: NativeModule.compiledWithCache,
+  nativeModuleWrap(script) {
+    return NativeModule.wrap(script);
+  },
+  // Modules with source code compiled in js2c that
+  // cannot be compiled with the code cache
+  cannotUseCache: [
+    'config',
+    // TODO(joyeecheung): update the C++ side so that
+    // the code cache is also used when compiling these
+    // two files.
+    'internal/bootstrap/loaders',
+    'internal/bootstrap/node'
+  ]
+};

lib/internal/bootstrap/loaders.js

@@ -125,10 +125,15 @@
 
   const config = getBinding('config');
 
+  const codeCache = getInternalBinding('code_cache');
+  const compiledWithoutCache = NativeModule.compiledWithoutCache = [];
+  const compiledWithCache = NativeModule.compiledWithCache = [];
+
   // Think of this as module.exports in this file even though it is not
   // written in CommonJS style.
   const loaderExports = { internalBinding, NativeModule };
   const loaderId = 'internal/bootstrap/loaders';
+
   NativeModule.require = function(id) {
     if (id === loaderId) {
       return loaderExports;
@@ -229,7 +234,29 @@
     this.loading = true;
 
     try {
-      const script = new ContextifyScript(source, this.filename);
+      // (code, filename, lineOffset, columnOffset
+      // cachedData, produceCachedData, parsingContext)
+      const script = new ContextifyScript(
+        source, this.filename, 0, 0,
+        codeCache[this.id], false, undefined
+      );
+
+      // One of these conditions may be false when any of the inputs
+      // of the `node_js2c` target in node.gyp is modified.
+      // FIXME(joyeecheung):
+      // 1. Figure out how to resolve the dependency issue. When the
+      //    code cache was introduced we were at a point where refactoring
+      //    node.gyp may not be worth the effort.
+      // 2. Calculate checksums in both js2c and generate_code_cache.js
+      //    and compare them before compiling the native modules since
+      //    V8 only checks the length of the source to decide whether to
+      //    reject the cache.
+      if (!codeCache[this.id] || script.cachedDataRejected) {
+        compiledWithoutCache.push(this.id);
+      } else {
+        compiledWithCache.push(this.id);
+      }
+
       // Arguments: timeout, displayErrors, breakOnSigint
       const fn = script.runInThisContext(-1, true, false);
       const requireFn = this.id.startsWith('internal/deps/') ?

node.gyp

@@ -6,6 +6,7 @@
     'node_use_etw%': 'false',
     'node_use_perfctr%': 'false',
     'node_no_browser_globals%': 'false',
+    'node_code_cache_path%': '',
     'node_use_v8_platform%': 'true',
     'node_use_bundled_v8%': 'true',
     'node_shared%': 'false',
@@ -24,6 +25,7 @@
     'node_lib_target_name%': 'node_lib',
     'node_intermediate_lib_type%': 'static_library',
     'library_files': [
+      'lib/internal/bootstrap/cache.js',
       'lib/internal/bootstrap/loaders.js',
       'lib/internal/bootstrap/node.js',
       'lib/async_hooks.js',
@@ -396,6 +398,7 @@
         'src/module_wrap.h',
         'src/node.h',
         'src/node_buffer.h',
+        'src/node_code_cache.h',
         'src/node_constants.h',
         'src/node_contextify.h',
         'src/node_debug_options.h',
@@ -459,6 +462,11 @@
         'NODE_OPENSSL_SYSTEM_CERT_PATH="<(openssl_system_ca_path)"',
       ],
       'conditions': [
+        [ 'node_code_cache_path!=""', {
+          'sources': [ '<(node_code_cache_path)' ]
+        }, {
+          'sources': [ 'src/node_code_cache_stub.cc' ]
+        }],
         [ 'node_shared=="true" and node_module_version!="" and OS!="win"', {
           'product_extension': '<(shlib_suffix)',
           'xcode_settings': {

src/node.cc

@@ -22,6 +22,7 @@
 #include "node_buffer.h"
 #include "node_constants.h"
 #include "node_javascript.h"
+#include "node_code_cache.h"
 #include "node_platform.h"
 #include "node_version.h"
 #include "node_internals.h"
@@ -1595,10 +1596,18 @@ static void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
 
   Local<String> module = args[0].As<String>();
   node::Utf8Value module_v(env->isolate(), module);
+  Local<Object> exports;
 
   node_module* mod = get_internal_module(*module_v);
-  if (mod == nullptr) return ThrowIfNoSuchModule(env, *module_v);
-  Local<Object> exports = InitModule(env, mod, module);
+  if (mod != nullptr) {
+    exports = InitModule(env, mod, module);
+  } else if (!strcmp(*module_v, "code_cache")) {
+    // internalBinding('code_cache')
+    exports = Object::New(env->isolate());
+    DefineCodeCache(env, exports);
+  } else {
+    return ThrowIfNoSuchModule(env, *module_v);
+  }
 
   args.GetReturnValue().Set(exports);
 }

src/node_code_cache.h

@@ -0,0 +1,16 @@
+#ifndef SRC_NODE_CODE_CACHE_H_
+#define SRC_NODE_CODE_CACHE_H_
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#include "node_internals.h"
+
+namespace node {
+
+void DefineCodeCache(Environment* env, v8::Local<v8::Object> target);
+
+}  // namespace node
+
+#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#endif  // SRC_NODE_CODE_CACHE_H_

src/node_code_cache_stub.cc

@@ -0,0 +1,14 @@
+
+#include "node_code_cache.h"
+
+// This is supposed to be generated by tools/generate_code_cache.js
+// The stub here is used when configure is run without `--code-cache-path`
+
+namespace node {
+void DefineCodeCache(Environment* env, v8::Local<v8::Object> target) {
+  // When we do not produce code cache for builtin modules,
+  // `internalBinding('code_cache')` returns an empty object
+  // (here as `target`) so this is a noop.
+}
+
+}  // namespace node

test/code-cache/code-cache.status

@@ -0,0 +1,21 @@
+prefix code-cache
+
+# To mark a test as flaky, list the test name in the appropriate section
+# below, without ".js", followed by ": PASS,FLAKY". Example:
+# sample-test                        : PASS,FLAKY
+
+[true] # This section applies to all platforms
+
+[$system==win32]
+
+[$system==linux]
+
+[$system==macos]
+
+[$arch==arm || $arch==arm64]
+
+[$system==solaris] # Also applies to SmartOS
+
+[$system==freebsd]
+
+[$system==aix]

test/code-cache/test-code-cache.js

@@ -0,0 +1,42 @@
+'use strict';
+
+// Flags: --expose-internals
+// This test verifies that the binary is compiled with code cache and the
+// cache is used when built in modules are compiled.
+
+require('../common');
+const assert = require('assert');
+const {
+  types: {
+    isUint8Array
+  }
+} = require('util');
+const {
+  builtinSource,
+  codeCache,
+  cannotUseCache,
+  compiledWithCache,
+  compiledWithoutCache
+} = require('internal/bootstrap/cache');
+
+assert.strictEqual(
+  typeof process.config.variables.node_code_cache_path,
+  'string'
+);
+
+assert.deepStrictEqual(compiledWithoutCache, []);
+
+const loadedModules = process.moduleLoadList
+  .filter((m) => m.startsWith('NativeModule'))
+  .map((m) => m.replace('NativeModule ', ''));
+
+for (const key of loadedModules) {
+  assert(compiledWithCache.includes(key),
+         `"${key}" should've been compiled with code cache`);
+}
+
+for (const key of Object.keys(builtinSource)) {
+  if (cannotUseCache.includes(key)) continue;
+  assert(isUint8Array(codeCache[key]) && codeCache[key].length > 0,
+         `Code cache for "${key}" should've been generated`);
+}

test/code-cache/testcfg.py

@@ -0,0 +1,6 @@
+import sys, os
+sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
+import testpy
+
+def GetConfiguration(context, root):
+  return testpy.ParallelTestConfiguration(context, root, 'code-cache')