Reorganize Multiprocess and implement for Windows

util/file/file_io_win.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 26 matching lines @@
 // TODO(scottmg): Handle > DWORD sized writes if necessary.
 
 ssize_t ReadFile(FileHandle file, void* buffer, size_t size) {
   DCHECK(!IsSocketHandle(file));
   DWORD size_dword = base::checked_cast<DWORD>(size);
   DWORD total_read = 0;
   char* buffer_c = reinterpret_cast<char*>(buffer);
   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) {
       // Zero bytes read for a file indicates reaching EOF. Zero bytes read from
       // a pipe indicates only that there was a zero byte WriteFile issued on
       // the other end, so continue reading.
       break;
     }
 
     buffer_c += bytes_read;
@@ skipping 73 matching lines @@
   return new_offset.QuadPart;
 }
 
 bool LoggingCloseFile(FileHandle file) {
   BOOL rv = CloseHandle(file);
   PLOG_IF(ERROR, !rv) << "CloseHandle";
   return rv;
 }
 
 }  // namespace crashpad