测试readbytes是否等于在异步模式下使用ReadFile读取字节

Question

I have an error scenario wherein im trying to read more bytes than actually present in the file. In synchronous case it fails and appropriate error is reported because we call waitFrObject and wait till the io is complete and test if readbytes >= ToReadbytes. But in case of asynchronous we start reading , ignore IO peding status flage returned by ReadFile( which is expected) and continue our operation. So the error is actually not caught in asynchronous case. Now if i check wait for the IO to complete to check if readbytes>=ToreadBytes then it wont be asynchronous anymore as we are waitng. So how do i deal with such a situation? ( Note -Reading more bytes than actually present is one of the ways to make error reproducible)

Im using windown's ReadFile function for reading.

Answer 1

Presumably you have some other thread that is waiting for the event triggered by the read completion, which will then go on to use the data. Just add the check after the wait, before you use the data.