Reorganize Multiprocess and implement for Windows

util/file/file_io_win.cc

Index: util/file/file_io_win.cc
diff --git a/util/file/file_io_win.cc b/util/file/file_io_win.cc
index 861f15acc64e2243c2b5d024bc68f7b947ff15e4..264cc4342e026f40dd2051637c6c6279d4277414 100644
--- a/util/file/file_io_win.cc
+++ b/util/file/file_io_win.cc
@@ -44,7 +44,12 @@ ssize_t ReadFile(FileHandle file, void* buffer, size_t size) {
   while (size_dword > 0) {
     DWORD bytes_read;
     BOOL success = ::ReadFile(file, buffer_c, size_dword, &bytes_read, nullptr);
-    if (!success && GetLastError() != ERROR_MORE_DATA) {
+    if (!success && GetLastError() == ERROR_BROKEN_PIPE) {

[Mark Mentovai, 2015/01/28 19:58:27]

A light restructuring to keep rechecking the same things over and over again
would clarify this a bit.

  if (!success) {
    // Alternatively: const DWORD error = GetLastError();
    if (GetLastError() == ERROR_BROKEN_PIPE) {
    } else if (GetLastError() != ERROR_MORE_DATA) {
    }
  } else if (bytes_read == 0 && GetFileType(file) != FILE_TYPE_PIPE) {
  }

[scottmg, 2015/01/28 22:14:57]

Done.

+      // When reading a pipe and the write handle has been closed, ReadFile
+      // fails with ERROR_BROKEN_PIPE, but only once all pending data has been
+      // read.
+      break;
+    } else if (!success && GetLastError() != ERROR_MORE_DATA) {
       return -1;
     } else if (success && bytes_read == 0 &&
                GetFileType(file) != FILE_TYPE_PIPE) {