delay(9) [freebsd man page]

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

NAME

     DELAY -- busy loop for an interval

SYNOPSIS

     #include <sys/types.h>
     #include <sys/systm.h>

     void
     DELAY(int delay);

DESCRIPTION

     Delay for delay microseconds (1/1000000th of a second).

SEE ALSO

     pause(9)

AUTHORS

     This manual page was written by Alfred Perlstein.

BSD
								  April 20, 2013							       BSD

DELAY(9r)																 DELAY(9r)

NAME

       DELAY - General: Delays the calling routine a specified number of microseconds

SYNOPSIS

       void DELAY(
	       int Specifies n );

ARGUMENTS

       Specifies the number of microseconds for the calling process to spin.

DESCRIPTION

       The  DELAY  routine  delays  the  calling  routine  a  specified  number of microseconds.  DELAY spins, waiting for the specified number of
       microseconds to pass before continuing execution.

       For example, the following code results in a 10000-microsecond (10-millisecond) delay:

	.
	.
	.
	DELAY(10000);
	.
	.
	.

       The range of delays is system dependent, due to its relation to the granularity of the system clock. The system defines the number of clock
       ticks per second in the hz variable. Specifying any value smaller than 1 Hz to the DELAY routine results in an unpredictable delay. For any
       delay value, the actual delay may vary by plus or minus one clock tick.

       Using the DELAY routine is discouraged because the processor will be consumed for the specified time interval and therefore is  unavailable
       to  service other processes. In cases where kernel modules need timing mechanisms, you should use the sleep and timeout routines instead of
       the DELAY routine.  The most common usage of the DELAY routine is in the system boot path. Using DELAY in the boot path is often acceptable
       because there are no other processes in contention for the processor.

RETURN VALUES

       None

SEE ALSO

       Routines: sleep(9r), timeout(9r)

																	 DELAY(9r)