Make event-handlers edge-triggered and move socket-state to Dart.

runtime/bin/socket.cc

Index: runtime/bin/socket.cc
diff --git a/runtime/bin/socket.cc b/runtime/bin/socket.cc
index 351bfc66334c3f73d9b93394f2afae6ab4246f74..d87e0178c75f6af5b97405af0929e7165ee502dd 100644
--- a/runtime/bin/socket.cc
+++ b/runtime/bin/socket.cc
@@ -224,7 +224,9 @@ void FUNCTION_NAME(Socket_WriteList)(Dart_NativeArguments args) {
       DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 2));
   intptr_t length =
       DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 3));
+  bool short_write = false;
   if (short_socket_writes) {
+    if (length > 1) short_write = true;
     length = (length + 1) / 2;
   }
   Dart_TypedData_Type type;
@@ -238,7 +240,11 @@ void FUNCTION_NAME(Socket_WriteList)(Dart_NativeArguments args) {
   intptr_t bytes_written = Socket::Write(socket, buffer, length);
   if (bytes_written >= 0) {
     Dart_TypedDataReleaseData(buffer_obj);
-    Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
+    if (short_write) {

[Søren Gjesse, 2014/02/18 14:28:00]

Can we post a write event instead of this "trick"?

If not please rename short_write to simulate_short_write.

[Anders Johnsen, 2014/02/19 09:43:03]

It's extremely custom how we post such an event. I'll document this.

+      Dart_SetReturnValue(args, Dart_NewInteger(-bytes_written));
+    } else {
+      Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
+    }
   } else {
     // Extract OSError before we release data, as it may override the error.
     OSError os_error;