Added synchronous socket implementation to dart:io.

runtime/include/dart_api.h

 /*
  * 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.
  */
 
 #ifndef RUNTIME_INCLUDE_DART_API_H_
 #define RUNTIME_INCLUDE_DART_API_H_
 
 /** \mainpage Dart Embedding API Reference
@@ skipping 369 matching lines @@
  *
  * \param An error handle (See Dart_IsError)
  *
  * \return On success, this function does not return.  On failure, an
  *   error handle is returned.
  */
 DART_EXPORT Dart_Handle Dart_PropagateError(Dart_Handle handle);
 /* TODO(turnidge): Should this really return an error handle? */
 /* Consider just terminating. */
 
+/**
+ * Propagates error if 'handle' is an error handle.
+ *
+ * Provided for convenience.
+ */
+#define DART_CHECK_VALID_AND_PROPAGATE(handle)                                 \
+  {                                                                            \
+    if (Dart_IsError((handle))) {                                              \
+      Dart_PropagateError(handle);                                             \

[zra, 2017/04/10 21:39:43]

Dart_PropagateError is actually a little bit dangerous because it skips over C++
frames without giving any opportunity for cleanup, so I don't think we should be
making it any more convenient to use.

[bkonyi, 2017/04/11 01:30:51]

Ah okay, good to know. Removed.

+    }                                                                          \
+  }
+
 /* Internal routine used for reporting error handles. */
 DART_EXPORT void _Dart_ReportErrorHandle(const char* file,
                                          int line,
                                          const char* handle_string,
                                          const char* error);
 
 /* TODO(turnidge): Move DART_CHECK_VALID to some sort of dart_utils
  * header instead of this header. */
 /**
  * Aborts the process if 'handle' is an error handle.
@@ skipping 2929 matching lines @@
  */
 DART_EXPORT bool Dart_IsPrecompiledRuntime();
 
 
 /**
  *  Print a native stack trace. Used for crash handling.
  */
 DART_EXPORT void Dart_DumpNativeStackTrace(void* context);
 
 #endif /* INCLUDE_DART_API_H_ */ /* NOLINT */