Re: calculate throughputs within overlapped I/O and multithread

Dear all:

I am writing a program to calculate the throughput of serial
communication.
(COM1,COM2...etc.)
I use overlapped I/O and multithread.
And my problem is...
because of overlapped I/O, the I/O operations can executed in
background.
while I/O time decrease with high baud rate, the program execution
time affected my throughput calculation.
I create two thread (one for read, another for write) each serial
port.

for ex:

QueryPerformanceCounter(&mStarttoCount);
Readfile(hCom......); //with overlapped flag.
WaitforSingleObject(......);
if(wait success) QueryPerformanceCounter(&mEndCount);
CalculateThroughput();// (number of transmitted bytes )/(time)

I use QueryPerformanceFrequency() and QueryPerformanceCounter() to
calculate the time passed.

Then I found if I use high baud rate, the time is far away from the
ideal value.
After some test, I found the program execution time affected it.

So..How can I avoid this kind of effect?
One of my colleague suggested that my program did not have good
efficiency so the execution time affects the result. But I don't know
how to increase the efficiency of my codes.

best regards.
by Selina