Script Library: 1222 scripts
 

threaddemo.r

REBOL [ Title: "Threads Demo" Date: 5-Jan-2005 Version: 1.0 Author: "François Jouen" File: %threaddemo.r Purpose: { show multithreading with rebol (all versions) } library: [ level: 'intermediate platform: 'all type: [tool demo] domain: [gui] tested-under: 'win 'Mac Classic 'Linux 'BeOS support: none license: 'pd ] ] ; Call RThread Library free-mem: func ['word] [set :word make none! recycle] Scheduler: func [/local athread ThreadCount] [ make object! [ ThreadCount: make integer! 0 ; public properties ThreadList: copy [] Delay: make integer! 0 ;object methods AppendThread: func [athread] [append ThreadList athread ThreadCount: ThreadCount + 1] RemoveThread: func [id] [remove at ThreadList id ThreadCount: ThreadCount - 1] StartLoop: does [ for i 1 ThreadCount 1 [ athread: pick ThreadList i athread/TAwake if athread/TActivated [athread/TExecute] athread/TSleep 0] ] StartMessageLoop: does [ for i 1 ThreadCount 1 [ athread: pick ThreadList i athread/TCount: athread/TCount + 1 athread/TGetMessage if athread/TActivated [athread/TExecute] wait delay ] ] ] ] RTHread: func [ id priority /local Tcount TCall] [ make object! [ ; define first properties TCount: make integer! -1 TCall: make integer! 0 TId: id ; Thread number TPriority: priority ; thread priority. values: 1 to N (High to Low) TTerminated: make logic! false ; Done? TActivated: make logic! false ; Suspended ? TFreeOnTerminate: make logic! true ; free memory on terminate TMessageList: copy [] ; define now the methods TSleep: make function! [value] [wait value TActivated: false] TAwake: make function! [] [ if not TTerminated [ TCount: TCount + 1 tt: remainder TCount TPriority if tt == 0 [TActivated: true TCall: TCall + 1]] ] TSendMessage: make function! [athread message] [ append clear athread/TMessageList message; the message stored in the thread message list ] TGetMessage: make function! [] [message: last TMessageList switch message [ "Activate" [TActivated: true] "Suspend" [TActivated: false] "Terminate" [TActivated: false TTerminated: true] ] ] TExecute: [] ;please overide this function! TTerminate: [] ;please overide this function! ] ] x: 0 col: white plot: copy [pen col line] ;first thread routine Show_Image: does [ x: x + 1 if x > 640 [Clear_Screen ] y: random 450 + 10 append plot to-pair compose [(x) (y)] ; suspend the first thread and call the second one if not none? t2 [ t1/TsendMessage t1 "Suspend" t1/TsendMessage t2 "Activate"] ;show points according to the thread priority tt: remainder t1/TCount t1/TPriority if tt == 0 [show visu] ] Clear_Screen: does [ x: 0 plot: copy [pen col line] append clear visu/effect reduce ['draw plot] show visu ] ;second thread Show_Time: does [ ; suspend the second thread and call the first one if not none? t1 [t2/TsendMessage t2 "Suspend" t2/TsendMessage t1 "Activate"] tt: remainder t2/TCount t2/TPriority ;show time according to the thread priority tt: remainder t1/TCount t1/TPriority if tt == 0 [ timer/text: now/time show timer] ] ; create threads 1 and 2 t1: RThread 1 1 t2: RThread 2 10 ; overide TExecute method for each thread t1/TExecute: :Show_Image t2/TExecute: :Show_Time ;create Scheduler sch: Scheduler ;register threads sch/AppendThread t1 sch/AppendThread t2 ; set scheduler delay sch/Delay: 0 ; create messages t1/TSendMessage T1 "Activate" t1/TSendMessage T2 "Suspend" mwin: layout [ across at 5x5 visu: box 640x480 blue frame black at 5x500 timer: info 150 ; to show asynchronous event process: modify Thread1 priority sl: slider 200x24 [maxi: to-integer sl/data * 60 if maxi < 1 [maxi: 1 ] t1/TPriority: maxi slt/text: maxi show slt] slt: info 40 "1" at 420x500 button 50 "Clear" [Clear_Screen] button 50 "Start" [maxi: 60 stop: false append visu/effect reduce ['draw plot] until [sch/StartMessageLoop stop]] ; start scheduler Message Loop processing button 50 "Stop" [stop: true]; stop threads button 50 "Exit" [ if t1/TFreeOnTerminate [free-mem T1 ] if t2/TFreeOnTerminate [free-mem T2 ] free-mem sch quit] ] view center-face mwin
halt ;; to terminate script if DO'ne from webpage