- Its API is virtually identical to SocketWaitEvent but for Pty processes.
- Provides a mechanism for waiting on multiple pseudoterminal (pty) processes to become ready for I/O operations.
- On windows it uses I/O Completion Ports (IOCP) to wait for events on process and pipe handles.
- On POSIX-compliant operating systems it uses the poll() system call to wait for events on pty/file descriptors
- On all platform this class effectively removes the  limitation of max 64 wait objects.