IPC: Add more debug logic (crash tracking)

ipc/ipc_channel_win.cc

Index: ipc/ipc_channel_win.cc
diff --git a/ipc/ipc_channel_win.cc b/ipc/ipc_channel_win.cc
index 9741dda05a13750f486d21f792f0c4aa6b3b7f65..0dcde1746d2237b84f857734da08f2415573f82e 100644
--- a/ipc/ipc_channel_win.cc
+++ b/ipc/ipc_channel_win.cc
@@ -63,10 +63,11 @@ ChannelWin::ChannelWin(const IPC::ChannelHandle &channel_handle,
       peer_pid_(base::kNullProcessId),
       waiting_connect_(mode & MODE_SERVER_FLAG),
       processing_incoming_(false),
-      weak_factory_(this),
       validate_client_(false),
+      writing_(false),
       debug_flags_(0),
-      client_secret_(0) {
+      client_secret_(0),
+      weak_factory_(this) {
   CreatePipe(channel_handle, mode);
 }
 
@@ -426,6 +427,8 @@ bool ChannelWin::ProcessOutgoingMessages(
   Message* m = output_queue_.front();
   DCHECK(m->size() <= INT_MAX);
   debug_flags_ |= WRITE_MSG;
+  CHECK(!writing_);
+  writing_ = true;
   BOOL ok = WriteFile(pipe_,
                       m->data(),
                       static_cast<int>(m->size()),
@@ -441,6 +444,7 @@ bool ChannelWin::ProcessOutgoingMessages(
 

[cpu_(ooo_6.6-7.5), 2014/07/29 19:47:20]

ERROR_IO_PENDING is the normal case, right?

so writing_ will be true and a second write could come along.. then 430 will
fire.

I am probably not understanding how this works then?

[rvargas (doing something else), 2014/07/29 20:36:21]

Because we are reusing the same overlapped structure, we cannot issue a second
write until the first one completes. When the first one completes, OnIoCompleted
will be called, and line 507 clears the flag for the next write.

       return true;
     }
+    writing_ = false;
     LOG(ERROR) << "pipe error: " << err;
     return false;
   }
@@ -498,6 +502,9 @@ void ChannelWin::OnIOCompleted(
       ok = ProcessIncomingMessages();
   } else {
     DCHECK(context == &output_state_.context);
+    CHECK(writing_);
+    CHECK(output_state_.is_pending);
+    writing_ = false;
     debug_flags_ |= WRITE_COMPLETED;
     if (debug_flags_ & WAIT_FOR_WRITE) {
       CHECK(!(debug_flags_ & WAIT_FOR_WRITE_COMPLETE));