Call Class Members from Interrupt Routine
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A timing message needs to go out every 20 msec, thats why I wanted to use this interrupt facility on the PCI card. Most other data goes out at 100 msec or 300 msec, which wold be OK for Windows timers. I may be wrong but is not Windows limited to 55 msec accuracy? So do you think that this solution is poor? Andy
Windows timer resuloution is about 10 ms, so if you want a timer at 20 you can do ith with the windows timer. Less than this you have to go to specific HW, or, on later windows OSs, apparently you can change the timer, but it is apparently illadvised. So yes, your solution will incur a performance hit because of the kernel to user transition. I took over a sw and driver design once that wrote data byte by byte to a RAM pack. It took 30 seconds to fill the thing with data. I changed it to writing 2 k packets at a time. It too 250 ms to fill it with data. Thats the cost of switching form user to kernel to user every byte, as oposed to evert 2k bytes. Heavy eh?
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