Details

Here are a few further details about asynchronous socket I/O.

say/exp_log some-text
say/exp_syslog some-text
If these say commands are issued in the client session, the commands are passed to the server. The client has no open log-files.

* = fd_info(0)
Displays an informational line about the first connected client.

Suppose that there is an ONLINE process, the master, that speaks directly to the main data bus, and a network session (the client) that does all I/O via sockets. The following statements apply:

• The master reads the sockets
  • when it waits for input from the keyboard
  • during timer wait states
  • during MCA wait states
  • before the during_xxx_scan.gra file is executed
  • by calling the function serve_clients().
• The timer wait states of the client cannot be interrupted.
• All commands are sequentially executed.
• It is the responsibility of the user to avoid race conditions, i.e.: the master and the client must not use the same VME boards (also both may speak to the same VME crate).