Send data in chunks when writing to socket.

runtime/bin/socket.cc

Index: runtime/bin/socket.cc
===================================================================
--- runtime/bin/socket.cc	(revision 3621)
+++ runtime/bin/socket.cc	(working copy)
@@ -5,6 +5,8 @@
 #include "bin/socket.h"
 #include "bin/dartutils.h"
 
+#include "platform/utils.h"
+
 #include "include/dart_api.h"
 
 
@@ -88,11 +90,23 @@
     length = (length + 1) / 2;
   }
 
-  uint8_t* buffer = new uint8_t[length];
-  result = Dart_ListGetAsBytes(buffer_obj, offset, buffer, length);
-  ASSERT(!Dart_IsError(result));
-  intptr_t total_bytes_written =
-      Socket::Write(socket, reinterpret_cast<void*>(buffer), length);
+  // Send data in chunks of maximum 16KB.
+  const intptr_t max_chunk_length = dart::Utils::Minimum(length, 16 * KB);
+  uint8_t* buffer = new uint8_t[max_chunk_length];
+  intptr_t total_bytes_written = 0;
+  intptr_t bytes_written = 0;
+  do {
+    intptr_t chunk_length =
+        dart::Utils::Minimum(max_chunk_length, length - total_bytes_written);
+    result = Dart_ListGetAsBytes(buffer_obj,
+                                 offset + total_bytes_written,
+                                 buffer,
+                                 chunk_length);
+    ASSERT(!Dart_IsError(result));
+    bytes_written =
+        Socket::Write(socket, reinterpret_cast<void*>(buffer), chunk_length);
+    total_bytes_written += bytes_written;
+  } while (bytes_written > 0 && total_bytes_written < length);
   delete[] buffer;
   Dart_SetReturnValue(args, Dart_NewInteger(total_bytes_written));
   Dart_ExitScope();