[ryanprichard]

To do that, you have to attach the conhost.exe process to its own console with AttachConsole, right? I tried that and also noticed the deadlock. An out-of-context handler avoids the deadlock, but then it's not synchronized.

The other interesting problems I found with that API were: (1) when editing an input line, EVENT_CONSOLE_CARET notifications were delayed, (2) if I hit ESC when editing an input line, the line would clear, but there'd be no update-region notification, and (3) it's impossible to distinguish between a call to ScrollConsoleScreenBuffer and the whole buffer scrolling because we've reached the end. ScrollConsoleScreenBuffer might scroll only part of the buffer.

winpty doesn't use the WinEvents API (yet), but it might be good enough to reduce polling when the console is idle.