Annotation of gforth/tasker.fs, revision 1.11
1.1 pazsan 1: \ Multitasker 19aug94py
2:
1.11 ! anton 3: \ Copyright (C) 1995,1996,1997,2001 Free Software Foundation, Inc.
1.4 anton 4:
5: \ This file is part of Gforth.
6:
7: \ Gforth is free software; you can redistribute it and/or
8: \ modify it under the terms of the GNU General Public License
9: \ as published by the Free Software Foundation; either version 2
10: \ of the License, or (at your option) any later version.
11:
12: \ This program is distributed in the hope that it will be useful,
13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: \ GNU General Public License for more details.
16:
17: \ You should have received a copy of the GNU General Public License
18: \ along with this program; if not, write to the Free Software
1.8 anton 19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.4 anton 20:
1.1 pazsan 21: Create sleepers sleepers A, sleepers A, 0 ,
22:
23: : link-task ( task1 task2 -- )
1.10 pazsan 24: \G LINK-TASK links task1 into the task chain of task2
25: over 2@ 2dup cell+ ! swap ! \ unlink task1
26: 2dup @ cell+ ! 2dup dup @ rot 2! ! ;
27:
28: : sleep ( task -- )
29: \G deactivates task
30: sleepers link-task ;
31: : wake ( task -- )
32: \G activates task
33: next-task link-task ;
1.1 pazsan 34:
35: : pause ( -- )
1.10 pazsan 36: \G PAUSE is the task-switcher
37: rp@ fp@ lp@ sp@ save-task !
38: next-task @ up! save-task @ sp!
39: lp! fp! rp! ;
1.1 pazsan 40:
41: : stop ( -- )
1.10 pazsan 42: \G STOP sleeps a task and switches to the next
43: rp@ fp@ lp@ sp@ save-task !
44: next-task @ up! save-task @ sp!
45: lp! fp! rp! prev-task @ sleep ;
1.1 pazsan 46:
1.6 jwilke 47: :noname ' >body @ ;
48: :noname ' >body @ postpone literal ;
49: interpret/compile: user' ( 'user' -- n )
1.10 pazsan 50: \G USER' computes the task offset of a user variable
1.1 pazsan 51:
1.10 pazsan 52: : NewTask ( stacksize -- Task ) dup 2* 2* udp @ + dup
53: \G NEWTASK creates a new, sleeping task
54: allocate throw + >r
55: r@ over - udp @ - next-task over udp @ move
56: r> over user' rp0 + ! dup >r
57: dup r@ user' lp0 + ! over -
58: dup r@ user' fp0 + ! over -
59: dup r@ user' sp0 + ! over -
60: dup r@ user' normal-dp + dup >r !
61: r> r@ user' dpp + ! 2drop
1.9 pazsan 62: 0 r@ user' current-input + !
1.10 pazsan 63: r> dup 2dup 2! dup sleep ;
1.1 pazsan 64:
1.10 pazsan 65: Create killer killer A, killer A,
66: : kill ( task -- )
67: \G kills a task - deactivate and free task area
68: dup killer link-task killer dup dup 2!
69: user' normal-dp + @ free throw ;
70:
71: : kill-task ( -- )
72: \G kills the current task, also on bottom of return stack of a new task
73: next-task @ up! save-task @ sp!
74: lp! fp! rp! prev-task @ kill ;
1.1 pazsan 75:
76: : (pass) ( x1 .. xn n task -- ) rdrop
77: [ ' kill-task >body ] ALiteral r>
1.5 jwilke 78: rot >r r@ user' rp0 + @ 2 cells - dup >r 2!
1.1 pazsan 79: r> swap 1+
1.5 jwilke 80: r@ user' fp0 + @ swap 1+
81: r@ user' lp0 + @ swap 1+
82: cells r@ user' sp0 + @ tuck swap - dup r@ user' save-task + !
1.1 pazsan 83: ?DO I ! cell +LOOP r> wake ;
84:
1.10 pazsan 85: : activate ( task -- )
86: \G activates the task.
87: \G Continues execution with the caller of ACTIVATE.
88: 0 swap (pass) ;
89: : pass ( x1 .. xn n task -- )
90: \G passes n parameters to the task and activates that task.
91: \G Continues execution with the caller of PASS.
92: (pass) ;
1.1 pazsan 93:
1.2 pazsan 94: : single-tasking? ( -- flag )
1.10 pazsan 95: \G checks if only one task is running
1.2 pazsan 96: next-task dup @ = ;
97:
98: : task-key BEGIN pause key? single-tasking? or UNTIL (key) ;
1.1 pazsan 99: : task-emit (emit) pause ;
100: : task-type (type) pause ;
101:
102: ' task-key IS key
103: ' task-emit IS emit
104: ' task-type IS type
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