delay.4th revision 222417
1222417Sjulian\ Copyright (c) 2008-2011 Devin Teske <devinteske@hotmail.com> 2222417Sjulian\ All rights reserved. 3222417Sjulian\ 4222417Sjulian\ Redistribution and use in source and binary forms, with or without 5222417Sjulian\ modification, are permitted provided that the following conditions 6222417Sjulian\ are met: 7222417Sjulian\ 1. Redistributions of source code must retain the above copyright 8222417Sjulian\ notice, this list of conditions and the following disclaimer. 9222417Sjulian\ 2. Redistributions in binary form must reproduce the above copyright 10222417Sjulian\ notice, this list of conditions and the following disclaimer in the 11222417Sjulian\ documentation and/or other materials provided with the distribution. 12222417Sjulian\ 13222417Sjulian\ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14222417Sjulian\ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15222417Sjulian\ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16222417Sjulian\ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17222417Sjulian\ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18222417Sjulian\ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19222417Sjulian\ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20222417Sjulian\ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21222417Sjulian\ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22222417Sjulian\ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23222417Sjulian\ SUCH DAMAGE. 24222417Sjulian\ 25222417Sjulian\ $FreeBSD: head/sys/boot/forth/delay.4th 222417 2011-05-28 08:50:38Z julian $ 26222417Sjulian 27222417Sjulianmarker task-delay.4th 28222417Sjulian 29222417Sjulian2 constant delay_default \ Default delay (in seconds) 30222417Sjulian3 constant etx_key \ End-of-Text character produced by Ctrl+C 31222417Sjulian13 constant enter_key \ Carriage-Return character produce by ENTER 32222417Sjulian27 constant esc_key \ Escape character produced by ESC or Ctrl+[ 33222417Sjulian 34222417Sjulianvariable delay_tstart \ state variable used for delay timing 35222417Sjulianvariable delay_delay \ determined configurable delay duration 36222417Sjulianvariable delay_cancelled \ state variable for user cancellation 37222417Sjulianvariable delay_showdots \ whether continually print dots while waiting 38222417Sjulian 39222417Sjulian: delay_execute ( -- ) 40222417Sjulian 41222417Sjulian \ make sure that we have a command to execute 42222417Sjulian s" delay_command" getenv dup -1 = if 43222417Sjulian drop exit 44222417Sjulian then 45222417Sjulian 46222417Sjulian \ read custom time-duration (if set) 47222417Sjulian s" loader_delay" getenv dup -1 = if 48222417Sjulian drop \ no custom duration (remove dup'd bunk -1) 49222417Sjulian delay_default \ use default setting (replacing bunk -1) 50222417Sjulian else 51222417Sjulian \ make sure custom duration is a number 52222417Sjulian ?number 0= if 53222417Sjulian delay_default \ use default if otherwise 54222417Sjulian then 55222417Sjulian then 56222417Sjulian 57222417Sjulian \ initialize state variables 58222417Sjulian delay_delay ! \ stored value is on the stack from above 59222417Sjulian seconds delay_tstart ! \ store the time we started 60222417Sjulian 0 delay_cancelled ! \ boolean flag indicating user-cancelled event 61222417Sjulian 62222417Sjulian false delay_showdots ! \ reset to zero and read from environment 63222417Sjulian s" delay_showdots" getenv dup -1 <> if 64222417Sjulian 2drop \ don't need the value, just existance 65222417Sjulian true delay_showdots ! 66222417Sjulian else 67222417Sjulian drop 68222417Sjulian then 69222417Sjulian 70222417Sjulian \ Loop until we have exceeded the desired time duration 71222417Sjulian begin 72222417Sjulian 25 ms \ sleep for 25 milliseconds (40 iterations/sec) 73222417Sjulian 74222417Sjulian \ throw some dots up on the screen if desired 75222417Sjulian delay_showdots @ if 76222417Sjulian ." ." \ dots visually aid in the perception of time 77222417Sjulian then 78222417Sjulian 79222417Sjulian \ was a key depressed? 80222417Sjulian key? if 81222417Sjulian key \ obtain ASCII value for keystroke 82222417Sjulian dup enter_key = if 83222417Sjulian -1 delay_delay ! \ break loop 84222417Sjulian then 85222417Sjulian dup etx_key = swap esc_key = OR if 86222417Sjulian -1 delay_delay ! \ break loop 87222417Sjulian -1 delay_cancelled ! \ set cancelled flag 88222417Sjulian then 89222417Sjulian then 90222417Sjulian 91222417Sjulian \ if the time duration is set to zero, loop forever 92222417Sjulian \ waiting for either ENTER or Ctrl-C/Escape to be pressed 93222417Sjulian delay_delay @ 0> if 94222417Sjulian \ calculate elapsed time 95222417Sjulian seconds delay_tstart @ - delay_delay @ > 96222417Sjulian else 97222417Sjulian -1 \ break loop 98222417Sjulian then 99222417Sjulian until 100222417Sjulian 101222417Sjulian \ if we were throwing up dots, throw up a line-break 102222417Sjulian delay_showdots @ if 103222417Sjulian cr 104222417Sjulian then 105222417Sjulian 106222417Sjulian \ did the user press either Ctrl-C or Escape? 107222417Sjulian delay_cancelled @ if 108222417Sjulian 2drop \ we don't need the command string anymore 109222417Sjulian else 110222417Sjulian evaluate \ evaluate/execute the command string 111222417Sjulian then 112222417Sjulian; 113