IPC: Add more debug info.

ipc/ipc_channel_win.cc

 // Copyright (c) 2012 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 "ipc/ipc_channel_win.h"
 
 #include <windows.h>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 48 matching lines @@
     : ChannelReader(listener),
       input_state_(this),
       output_state_(this),
       pipe_(INVALID_HANDLE_VALUE),
       peer_pid_(base::kNullProcessId),
       waiting_connect_(mode & MODE_SERVER_FLAG),
       processing_incoming_(false),
       validate_client_(false),
       writing_(false),
       debug_flags_(0),
+      write_error_(0),
+      last_write_error_(0),
+      write_size_(0),
       client_secret_(0),
       weak_factory_(this) {
   CreatePipe(channel_handle, mode);
 }
 
 ChannelWin::~ChannelWin() {
   Close();
 }
 
 void ChannelWin::Close() {
@@ skipping 353 matching lines @@
 
   if (INVALID_HANDLE_VALUE == pipe_)
     return false;
 
   // Write to pipe...
   Message* m = output_queue_.front();
   DCHECK(m->size() <= INT_MAX);
   debug_flags_ |= WRITE_MSG;
   CHECK(!writing_);
   writing_ = true;
+  write_size_ = static_cast<uint32>(m->size());
+  write_error_ = 0;
   BOOL ok = WriteFile(pipe_,
                       m->data(),
-                      static_cast<int>(m->size()),
-                      &bytes_written,
+                      write_size_,
+                      NULL,
                       &output_state_.context.overlapped);
   if (!ok) {
-    DWORD err = GetLastError();
-    if (err == ERROR_IO_PENDING) {
+    write_error_ = GetLastError();
+    if (write_error_ == ERROR_IO_PENDING) {
       output_state_.is_pending = true;
 
       DVLOG(2) << "sent pending message @" << m << " on channel @" << this
                << " with type " << m->type();
 
       return true;
     }
     writing_ = false;
-    LOG(ERROR) << "pipe error: " << err;
+    last_write_error_ = write_error_;
+    LOG(ERROR) << "pipe error: " << write_error_;
     return false;
   }
 
   DVLOG(2) << "sent message @" << m << " on channel @" << this
            << " with type " << m->type();
 
   output_state_.is_pending = true;
   return true;
 }
 
@@ skipping 89 matching lines @@
   int secret;
   do {  // Guarantee we get a non-zero value.
     secret = base::RandInt(0, std::numeric_limits<int>::max());
   } while (secret == 0);
 
   id.append(GenerateUniqueRandomChannelID());
   return id.append(base::StringPrintf("\\%d", secret));
 }
 
 }  // namespace IPC