Always mark stdout as blocking when using 'print'.

runtime/bin/builtin_natives.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/io_natives.h"
+#include "bin/platform.h"
 
 namespace dart {
 namespace bin {
 
 // Lists the native functions implementing basic functionality in
 // standalone dart, such as printing, file I/O, and platform information.
 // Advanced I/O classes like sockets and process management are implemented
 // using functions listed in io_natives.cc.
 #define BUILTIN_NATIVE_LIST(V)                                                 \
   V(Directory_Exists, 1)                                                       \
@@ skipping 75 matching lines @@
 void FUNCTION_NAME(Logger_PrintString)(Dart_NativeArguments args) {
   intptr_t length = 0;
   uint8_t* chars = NULL;
   Dart_Handle str = Dart_GetNativeArgument(args, 0);
   Dart_Handle result = Dart_StringToUTF8(str, &chars, &length);
   if (Dart_IsError(result)) {
     // TODO(turnidge): Consider propagating some errors here.  What if
     // an isolate gets interrupted by the embedder in the middle of
     // Dart_StringToUTF8?  We need to make sure not to swallow the
     // interrupt.
-    fputs(Dart_GetError(result), stdout);
+    Platform::PrintBlocking(stdout, "%s\n", Dart_GetError(result));
   } else {
-    fwrite(chars, sizeof(*chars), length, stdout);
+    Platform::PrintBlocking(stdout, "%.*s\n", length, chars);

[Søren Gjesse, 2013/10/01 07:16:39]

I was not aware of the * for precision.

[Anders Johnsen, 2013/10/01 09:05:21]

Let's see if all the platforms supports it :)

   }
-  fputc('\n', stdout);
-  fflush(stdout);
 }
 
 }  // namespace bin
 }  // namespace dart