add non working fast path

Author: Uzlopak

benchmark/navigator/navigator-on-line.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const common = require('../common.js');
+const assert = require('assert');
+
+const bench = common.createBenchmark(main, {
+  n: [1e4],
+});
+
+// Warm up.
+const length = 1024;
+const array = [];
+for (let i = 0; i < length; ++i) {
+  array.push(global.navigator.onLine);
+}
+
+function main({ n }) {
+  bench.start();
+  for (let i = 0; i < n; ++i) {
+    const index = i % length;
+    array[index] = global.navigator.onLine;
+  }
+  bench.end(n);
+
+  // Verify the entries to prevent dead code elimination from making
+  // the benchmark invalid.
+  for (let i = 0; i < length; ++i) {
+    assert.strictEqual(typeof array[i], 'boolean');
+  }
+}

src/node_external_reference.h

@@ -27,7 +27,7 @@ using CFunctionCallbackWithStrings =
              const v8::FastOneByteString& base);
 using CFunctionWithUint32 = uint32_t (*)(v8::Local<v8::Value>,
                                          const uint32_t input);
-
+using CFunctionReturnBool = bool (*)(v8::FastApiCallbackOptions& options);
 // This class manages the external references from the V8 heap
 // to the C++ addresses in Node.js.
 class ExternalReferenceRegistry {
@@ -43,6 +43,7 @@ class ExternalReferenceRegistry {
   V(CFunctionCallbackWithString)                                               \
   V(CFunctionCallbackWithStrings)                                              \
   V(CFunctionWithUint32)                                                       \
+  V(CFunctionReturnBool)                                                       \
   V(const v8::CFunctionInfo*)                                                  \
   V(v8::FunctionCallback)                                                      \
   V(v8::AccessorGetterCallback)                                                \

src/node_os.cc

@@ -19,9 +19,11 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+#include <stdio.h>
 #include "env-inl.h"
 #include "node_external_reference.h"
 #include "string_bytes.h"
+#include "v8-fast-api-calls.h"
 
 #ifdef __MINGW32__
 # include <io.h>
@@ -247,7 +249,7 @@ static void GetInterfaceAddresses(const FunctionCallbackInfo<Value>& args) {
   args.GetReturnValue().Set(Array::New(isolate, result.data(), result.size()));
 }
 
-static void GetOnLineStatus(const FunctionCallbackInfo<Value>& args) {
+static void SlowGetOnLineStatus(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   uv_interface_address_t* interfaces;
   int count, i;
@@ -274,6 +276,32 @@ static void GetOnLineStatus(const FunctionCallbackInfo<Value>& args) {
   return args.GetReturnValue().Set(false);
 }
 
+static bool FastGetOnLineStatus(v8::FastApiCallbackOptions& options) {
+  uv_interface_address_t* interfaces;
+  int count, i;
+
+  printf("FastGetOnLineStatus\n");
+  int err = uv_interface_addresses(&interfaces, &count);
+
+  if (err) {
+    options.fallback = true;
+    return false;
+  }
+
+  for (i = 0; i < count; i++) {
+    if (interfaces[i].is_internal == false) {
+      uv_free_interface_addresses(interfaces, count);
+      return true;
+    }
+  }
+
+  uv_free_interface_addresses(interfaces, count);
+  return false;
+}
+
+v8::CFunction fast_get_on_line_status_(
+    v8::CFunction::Make(FastGetOnLineStatus));
+
 static void GetHomeDirectory(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   char buf[PATH_MAX];
@@ -429,7 +457,11 @@ void Initialize(Local<Object> target,
   SetMethod(context, target, "getPriority", GetPriority);
   SetMethod(
       context, target, "getAvailableParallelism", GetAvailableParallelism);
-  SetMethod(context, target, "getOnLineStatus", GetOnLineStatus);
+  SetFastMethod(context,
+                target,
+                "getOnLineStatus",
+                SlowGetOnLineStatus,
+                &fast_get_on_line_status_);
   SetMethod(context, target, "getOSInformation", GetOSInformation);
   target
       ->Set(context,
@@ -446,7 +478,9 @@ void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
   registry->Register(GetFreeMemory);
   registry->Register(GetCPUInfo);
   registry->Register(GetInterfaceAddresses);
-  registry->Register(GetOnLineStatus);
+  registry->Register(SlowGetOnLineStatus);
+  registry->Register(FastGetOnLineStatus);
+  registry->Register(fast_get_on_line_status_.GetTypeInfo());
   registry->Register(GetHomeDirectory);
   registry->Register(GetUserInfo);
   registry->Register(SetPriority);