[syslinux] proper way to sleep

[H. Peter Anvin]

Miguel wrote:
> This is not spam about sleep aids :)
> 
> Q: Is there a 'standard' way to sleep for a specified number of BIOS ticks
> (or seconds) in a com32 program?
> 
> I grepped through the com32 library source and didn't find anything for
> 'sleep' or 'tick'.
> 
> If not, you may want to consider adding:
>   void syslinux_sleep(int seconds);
>   void syslinux_sleep_bios_ticks(int ticks);
> 
> or something like that.

Not sleep, but there is a standard busy wait, so you could have
something like:

#include <syslinux/idle.h>
#include <sys/times.h>

void syslinux_sleep_ticks(int ticks)
{
	clock_t start = times(NULL);

	while (times(NULL) - start < ticks)
		syslinux_idle();
}

void syslinux_sleep(int seconds)
{
	syslinux_sleep_ticks(seconds*CLK_TCK);
}