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Re: libc-time-clock test doesn't seem to be written correctly??


No need. That synchronization is already done by virtue of this function itself being called in a tight loop and the first few results discarded (the SKIPPED_SAMPLES in the test). So when this function returns, clock() will still have "just changed" and the function is then immediately called again. If nothing else, there are a consistent number of instructions between calls to clock().
yes. there are consistent number of instructions between calls to clock(). But

the time taken to reach Ith iteration in consecutive calls to clock_loop is not

guaranteed to be multiple of clock() updation time. That way it is highly possible that - first time the clock() value change was observed in iteration number (say 100) and it can deviate from this in gradual manner either on increasing/decreasing side.

currently SAMPLES is set to 30, changing it to a higher value say 500, is likely

to lead to a observable pattern to you too (that can explain initiation of this discussion).

// ???????????????
// why should following be a fail condition in test where we are trying to
// check for clock stability
// ???????????????

It's a test, and testing for stability is the main goal but not the only one. Let's test for things that shouldn't happen.
you didn't clarify the doubt. But sure, for low SAMPLES values of 30 wrap

around isnot expected to happen, if that's what you mean.


-- regards sandeep ----------------------------------------------------------------------- Ashes to ashes,dust to dust, if the Lord won't have you, the Devil must. -----------------------------------------------------------------------


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