Win32Messages

This is a sample used to investigate how Windows uses the window message pump.

The application can be started as "flooder" or as "receiver" using the two command lines -flooder or -receiver:

• as a receiver, the application will wait for synchronization and then will wait for a custome message to enter a "sleep mode" where the messages from the pump are not extracted
• as a flooder, the application will wait for synchronization and then can send a "blocking message" to the receiver to block it; then will flood its message pump with messages

the synchronization is performed through a piece of shared memory.

Flooder window

Started with the -flooder switch; waits for the Receiver to "connect" and informs about this in the status bar. The "Start" and "Stop" buttons send a user message to the connected Receiver instance: when the "Freeze" button is pressed a message is sent to the Receiver which stops handling messages.

Receiver window

Started with the -receiver switch; waits for the Flooder to "connect" and informs about this in the status bar. The numeric updown can be used to set the time, in seconds, the message pump will freeze when the Flooder will send the special user message to do so.