delay(9) [netbsd man page]

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

DELAY.4TH(8)						    BSD System Manager's Manual 					      DELAY.4TH(8)

NAME

     delay.4th -- FreeBSD debugging boot module

DESCRIPTION

     The file that goes by the name of delay.4th is a set of commands designed to add debugging capabilities to loader(8).  The commands of
     delay.4th by themselves are not enough for most uses.  Please refer to the examples below for the most common situations, and to loader(8)
     for additional commands.

     Before using any of the commands provided in delay.4th, it must be included through the command:

	   include delay.4th

     This line is present in /boot/beastie.4th file, so it is not needed (and should not be re-issued) in a normal setup.

     The commands provided by it are:

	   delay_execute	  Executes the [string] procedure stored in the delay_command environment variable after loader_delay seconds.

				  If the optional delay_showdots environment variable is set, a continuous series of dots is printed.

				  During the duration, the user can either press Ctrl-C (or Esc) to abort or ENTER to proceed immediately.

     The environment variables that effect its behavior are:

	   delay_command
		     The command to be executed by delay_execute.

	   loader_delay
		     The duration (in seconds) to delay before executing delay_command.

	   delay_showdots
		     If set, will cause delay_execute to print a continuous series of dots during the delay duration.

FILES

     /boot/loader      The loader(8).
     /boot/delay.4th   delay.4th itself.
     /boot/loader.rc   loader(8) bootstrapping script.

EXAMPLES

     Introducing a 5-second delay before including another file from /boot/loader.rc:

	   include /boot/delay.4th
	   set delay_command="include /boot/other.4th"
	   set delay_showdots
	   set loader_delay=5
	   delay_execute

SEE ALSO

     loader.conf(5), beastie.4th(8), loader(8), loader.4th(8)

HISTORY

     The delay.4th set of commands first appeared in FreeBSD 9.0.

AUTHORS

     The delay.4th set of commands was written by Devin Teske <dteske@FreeBSD.org>.

BSD
								   May 18, 2011 							       BSD