Multithread problem

[Massimiliano Conti]

Hello ! I'm writing a program that have to write some data in COM1 and after wait for an answer from COM2, before sending another thing. I'm using two threads: in the first I send data to COM1, in the other I have only called InstallCOM Callback for the COM2 and created a while auto-loop to avoid the end of the thread. In the first thread I wait for the receiving of data from COM2, staying in a loop that will end when a flag is setted; and this flag will be setted by the com callback installed in the second thread. Unfortunately it doesn't work correctly: the program send correctly data from COM1 and waits waits waits... datas arrived in COM2 doesn't call the comcallback, until the first thread is busy in the waiting loop. Why second thread doesn't work
if the first thread is busy ?
Thank you very much !

[msaxon]

The help for InstallComCallback says:

""
...The callback function is called whenever any of the events you specify in eventMask occur on the COM port and you allow the system to process events. The system can process events in the following situations:

- You call RunUserInterface and none of your callback functions is currently executing.

- You call GetUserEvent.

- You call ProcessSystemEvents.
""

So the while loop at the end of your second thread must for example call ProcessSystemEvents on a regular basis or the callback will never happen.

--
Martin.

[Massimiliano Conti]

Martin, thank you for your answer. Obviously I forgot to put the 'ProcessSystemEvents' inside the loop of the thread where I installed the callback.

Thank you again,

Massimiliano