netbsd man page for delay

DELAY(9)						   BSD Kernel Developer's Manual						  DELAY(9)

NAME
     delay, DELAY -- microsecond delay

SYNOPSIS
     #include <machine/param.h>

     void
     delay(unsigned int us);

     void
     DELAY(unsigned int us);

DESCRIPTION
     Wait approximately us microseconds.

     The delay is implemented as a machine loop, preventing events other than interrupt handlers for unmasked interrupts to run.  DELAY() is reen-
     trant (doesn't modify any global kernel or machine state) and is safe to use in interrupt or process context.

     For long delays, condition variables should be considered, however they can only be used from process context and their resolution is limited
     by the system clock frequency.

SEE ALSO
     condvar(9), hz(9), kpause(9)

BSD
								   July 20, 2011							       BSD