## Why Does Sleep(1) in WinAPI Cause a Lengthier Slumber Than Expected?

WinAPI Sleep Function Conundrum: Lengthier Slumber Than Expected

When invoking the WinAPI Sleep function with a parameter of 1, users may encounter thread delays exceeding the intended duration. In fact, a repeated series of 100 Sleep(1) calls has yielded a total sleep time of 1500ms, much greater than the stipulated 100ms.

Cause of the Extended Sleep:

This behavior is inherent in the Windows thread scheduler. It operates with a time quantum, or a defined period during which a thread can execute. Non-zero delays are inherently rounded up to the nearest complete quantum.

Plausible System Issues:

While the observed behavior is typical, it can be advantageous to rule out potential system issues that might exacerbate the problem:

• Motherboard (MOBO): Faulty MOBO hardware can impact clock accuracy, contributing to longer sleep periods.
• CPU: Similar to MOBO issues, CPU irregularities can also lead to timing discrepancies.
• Windows Installation: System errors or incomplete installations can disrupt the timekeeping capabilities of Windows.

Additional Considerations:

It's noteworthy that other running programs can adjust the system-wide timer resolution, potentially resulting in a smaller quantum size. This can explain instances where Sleep(1) delays are reported to be within the intended 1ms timeframe. The default timer resolution in Windows 7 should be around 15.6ms, not 1ms.

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