[fpc-pascal] USB Human Interface Devices

[James Richters]

I use circular buffers for another project as well, but I made my own.. and the program doesn't use threads... it's buffering data being sent to a serial port in a really complicated way with a series of loops and timers to manage to function in a single thread...  I'm thinking of overhauling it to work with threads as it will greatly simplify things and probably perform better as well.    It sounds like there is already circular buffer functions available in FPC?  I would really like to see your code sample if you don't mind, it all sounds very useful!   

James

-----Original Message-----
From: fpc-pascal <fpc-pascal-bounces at lists.freepascal.org> On Behalf Of Brian
Sent: Thursday, August 29, 2019 11:57 AM
To: fpc-pascal at lists.freepascal.org
Subject: Re: [fpc-pascal] USB Human Interface Devices

Yes , and it works well on Linux.

I use it on a circular (ring) buffer where the main program reads data from the circular buffer and increments the read index while a totally random thread reads data from an incoming Ethernet UDP , serial port or a custom hardware port , writes to the circular buffer and increments the write index.

The functions used are :
procedure ResetEvent;
procedure SetEvent;
function WaitFor();  // one of the events in your program READ or WRITE must wait until the other event finishes.
	

The condition for a read of the circular buffer is WriteIndex <> ReadIndex which is in the main loop (not a thread) which is continuously polled in the main loop.

Hope this helps. I can send a code clip but not until next week (out of the
office) , showing how it is configured.