mirror of
https://github.com/forth-ev/VolksForth.git
synced 2024-11-19 02:08:38 +00:00
86 lines
5.2 KiB
Forth
86 lines
5.2 KiB
Forth
\ *** Block No. 0 Hexblock 0
|
|
\ ks 22 dez 87
|
|
The multitasker is a simple yet powerful round robin scheme
|
|
with explicit task switching. This has the major advantage
|
|
that the system switches tasks only in known states.
|
|
Hence the difficulties in synchronizing tasks and locking
|
|
critical portions of code are greatly minimized or simply
|
|
do not exist at all.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\ *** Block No. 1 Hexblock 1
|
|
\ Multitasker loadscreen ks 03 apr 88
|
|
Onlyforth \needs Assembler 2 loadfrom asm.scr
|
|
|
|
Code stop $E990 # U ) mov ' pause @ # jmp end-code
|
|
|
|
: singletask [ ' noop @ ] Literal ['] pause ! ;
|
|
: multitask [ ' pause @ ] Literal ['] pause ! ;
|
|
|
|
1 3 +thru .( Multitasker geladen) cr
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\ *** Block No. 2 Hexblock 2
|
|
\ pass activate ks 1 jun 87
|
|
|
|
: pass ( n0 ... nr-1 Taddr r -- )
|
|
BEGIN [ rot ]
|
|
swap $E9CD over ! \ awake Task
|
|
r> -rot \ Stack: IP r addr
|
|
8 + >r \ s0 of Task
|
|
r@ 2+ @ swap \ Stack: IP r0 r
|
|
2+ 2* \ bytes on Taskstack incl. r0 & IP
|
|
r@ @ over - \ new SP
|
|
dup r> 2- ! \ into Ssave
|
|
swap bounds ?DO I ! 2 +LOOP ; restrict
|
|
|
|
: activate ( Taddr -- ) 0 \ [ ' pass >body ] Literal >r ;
|
|
[ -rot ] REPEAT ; restrict
|
|
|
|
\ *** Block No. 3 Hexblock 3
|
|
( Building a Task ks 8 may 84 )
|
|
|
|
| : taskerror ( string -- ) standardi/o singletask
|
|
." Task error: " count type multitask stop ;
|
|
|
|
: sleep ( addr -- ) $90 swap c! ;
|
|
|
|
: wake ( addr -- ) $CD swap c! ;
|
|
|
|
: rendezvous ( semaphoraddr -- )
|
|
dup unlock pause lock ;
|
|
|
|
|
|
|
|
|
|
|
|
\ *** Block No. 4 Hexblock 4
|
|
\ Task ks 1 jun 87
|
|
|
|
: Task ( rlen slen -- ) clear
|
|
0 Constant here 2- >r \ addr of task constant
|
|
here -rot \ here for Task dp
|
|
even allot even \ allot dictionary area
|
|
here r> ! \ set task constant addr
|
|
up@ here $100 cmove \ init user area
|
|
here $E990 , \ JMP opcode
|
|
up@ 2+ dup dup @ + here - ,
|
|
2dup - 2- swap ! \ link task
|
|
0 , dup 2- dup , , \ ssave and s0
|
|
2dup + , \ here + rlen = r0
|
|
rot , \ dp
|
|
under + dp ! 0 , \ allot rstack
|
|
['] taskerror [ ' errorhandler >body c@ ] Literal rot + ! ;
|