Gather trace data by waiting on handles with a fixed timeout

mojo/common/data_pipe_utils.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/common/data_pipe_utils.h"
 
 #include <stdio.h>
 
 #include "base/message_loop/message_loop.h"
 #include "base/task_runner_util.h"
@@ skipping 74 matching lines @@
     MojoResult result =
         BeginWriteDataRaw(destination.get(), &buffer, &buffer_num_bytes,
                           MOJO_WRITE_DATA_FLAG_NONE);
     if (result == MOJO_RESULT_OK) {
       char* char_buffer = static_cast<char*>(buffer);
       uint32_t byte_index = 0;
       while (it != source.end() && byte_index < buffer_num_bytes) {
         char_buffer[byte_index++] = *it++;
       }
       EndWriteDataRaw(destination.get(), byte_index);
+      if (it == source.end())
+        return true;
     } else if (result == MOJO_RESULT_SHOULD_WAIT) {
       result = Wait(destination.get(), MOJO_HANDLE_SIGNAL_WRITABLE,
                     MOJO_DEADLINE_INDEFINITE, nullptr);
       if (result != MOJO_RESULT_OK) {
         // If the consumer handle was closed, then treat as EOF.
         return result == MOJO_RESULT_FAILED_PRECONDITION;
       }
     } else {
       // If the consumer handle was closed, then treat as EOF.
       return result == MOJO_RESULT_FAILED_PRECONDITION;
     }
   }
 }
 
 }  // namespace common
 }  // namespace mojo