1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
\ Multitasker 19aug94py
Create sleepers sleepers A, sleepers A, 0 ,
\ LINK-TASK links task1 into the task chain of task2
: link-task ( task1 task2 -- )
over 2@ 2dup cell+ ! swap ! \ unlink task1
2dup @ cell+ ! 2dup dup @ rot 2! ! ;
: sleep ( task -- ) sleepers link-task ;
: wake ( task -- ) next-task link-task ;
\ PAUSE is the task-switcher
: pause ( -- )
rp@ fp@ lp@ sp@ save-task !
next-task @ up! save-task @ sp!
lp! fp! rp! ;
\ STOP sleeps a task and switches to the next
: stop ( -- )
rp@ fp@ lp@ sp@ save-task !
next-task @ up! save-task @ sp!
lp! fp! rp! prev-task @ sleep ;
\ USER' computes the task offset
: user' ( 'user' -- n )
' >body @ postpone literal ; immediate
interpretation:
' >body @ ;
\ NEWTASK creates a new, sleeping task
: NewTask ( n -- Task ) dup 2* 2* udp @ + dup
allocate throw + >r
r@ over - udp @ - next-task over udp @ move
r> over user' r0 + ! dup >r
dup r@ user' l0 + ! over -
dup r@ user' f0 + ! over -
dup r@ user' s0 + ! over -
dup r@ user' normal-dp + dup >r !
r> r@ user' dpp + ! + $10 +
r@ user' >tib + !
r> dup 2dup 2! dup sleep ;
: kill-task
next-task @ up! save-task @ sp!
lp! fp! rp! prev-task @ dup dup link-task user' normal-dp + @ free throw ;
: (pass) ( x1 .. xn n task -- ) rdrop
[ ' kill-task >body ] ALiteral r>
rot >r r@ user' r0 + @ 2 cells - dup >r 2!
r> swap 1+
r@ user' f0 + @ swap 1+
r@ user' l0 + @ swap 1+
cells r@ user' s0 + @ tuck swap - dup r@ user' save-task + !
?DO I ! cell +LOOP r> wake ;
: activate ( task -- ) 0 swap (pass) ;
: pass ( x1 .. xn n task -- ) (pass) ;
: single-tasking? ( -- flag )
next-task dup @ = ;
: task-key BEGIN pause key? single-tasking? or UNTIL (key) ;
: task-emit (emit) pause ;
: task-type (type) pause ;
' task-key IS key
' task-emit IS emit
' task-type IS type
|
