Threading in QB64pe (again)

[justsomeguy]

Hello all,

I have another test program that uses threads. This time it creates from 1 to 8 worker threads and they draw colored squares across the screen.

As before it needs a header file to setup threading. Its name is 'workers.h'

Code: (Select All)

// workers.h
// Threading Header
#include "pthread.h"
// Only needed for the SIGTERM Constant
#include <signal.h>
#include <unistd.h>
#include <time.h>

#define RETRYCOUNT 5
// Initialize Threads
static pthread_t thread[9];

typedef struct thread_data {
   int id;
} thread_data;

// Easy was to determine if a thread is running
bool threadRunning[] = {false,false,false,false,false,false,false,false,false,false};

// Setup Mutexes.
static pthread_mutex_t mutex[9];

// QB's names for the threaded Subs
// You can locate these in your ''qb64pe/internal/temp'' folder.
// I found these in the 'main.txt'
void SUB_WORKERTHREAD(int32*_SUB_WORKERTHREAD_LONG_ID);

// wrap the subs so that you can easily get the void* for pthread
void* RunWorker(void *arg){
    thread_data *tdata=(thread_data *)arg;
    int a = tdata->id;
    SUB_WORKERTHREAD((int32*)&a);
}

// These are the commands that are accessed by you program
void invokeWorker(int id){
    thread_data tdata;
    tdata.id = id;
    int icount = 0;
    if (!threadRunning[id]) {
        while(pthread_create( &thread[id], NULL, RunWorker, (void *)&tdata))
        {
            icount++;
            if (icount > RETRYCOUNT){
                return;
            }
            sleep(1);
        };
        pthread_mutex_init(&mutex[id], NULL);
        threadRunning[id] = true;
    }
    sleep(1);
}

void joinThread(int id){
    pthread_join(thread[id],NULL);
    threadRunning[id] = false;
}

void exitThread(){
    pthread_exit(NULL);
}

void killThread(int id){
    if (threadRunning[id]) {
        int iret = pthread_kill(thread[id], SIGTERM);
    }
}

void lockThread(int id){
    pthread_mutex_lock(&mutex[id]);
}

void unlockThread(int id){
    pthread_mutex_unlock(&mutex[id]);
}

And the QB side is as follows. Its name is whatever you like.

Code: (Select All)

DECLARE LIBRARY "./workers"

  SUB invokeWorker (BYVAL id AS LONG) ' start Lines thread

  SUB joinThread (BYVAL id AS LONG) ' wait til thread is finished

  SUB exitThread ' must be called as thread exits

  SUB killThread (BYVAL id AS LONG) ' kill the thread

  SUB lockThread (BYVAL id AS LONG) ' mutex lock

  SUB unlockThread (BYVAL id AS LONG) ' mutex unlock

END DECLARE



TYPE tWorker

  xstart AS LONG

  ystart AS LONG

  xsize AS LONG

  ysize AS LONG

  xdir AS _BYTE

  x AS LONG

  y AS LONG

  colour AS LONG

  command AS LONG

  sc AS LONG

  img AS _MEM

  offset AS _OFFSET

  dly AS _BYTE

END TYPE



DIM indx AS LONG

DIM ky AS STRING

DIM AS INTEGER tc



_TITLE "Worker Thread Test"



SCREEN _NEWIMAGE(800, 600, 32)

DO

  CLS

  PRINT "How many worker threads? Low spec machines should start less than 4."

  INPUT "(1 - 8, 0 to quit):"; tc

  IF tc = 0 THEN SYSTEM

LOOP UNTIL tc >= 1 AND tc <= 8

tc = tc - 1

CLS



DIM SHARED AS tWorker worker(tc)



FOR indx = 0 TO tc

  resetWorker indx

  worker(indx).sc = _NEWIMAGE(worker(indx).xsize + 1, worker(indx).ysize + 1, 32)

  worker(indx).img = _MEMIMAGE(worker(indx).sc)

NEXT

LOCATE 1

FOR indx = 0 TO tc

  PRINT "Starting thread:"; indx

  invokeWorker indx

NEXT

CLS

DO

  ky = INKEY$

  IF ky = "d" THEN

    FOR indx = 0 TO tc

      worker(indx).dly = NOT worker(indx).dly

    NEXT

  END IF



  IF ky = "s" THEN

    CLS

    FOR indx = 0 TO tc

      worker(indx).command = NOT worker(indx).command

      IF worker(indx).command THEN

        joinThread indx

      ELSE

        PRINT "Restarting thread:"; indx

        _DISPLAY

        invokeWorker indx

      END IF

    NEXT

    CLS

  END IF



  IF ky = CHR$(27) THEN

    FOR indx = 0 TO tc

      worker(indx).command = -1

      joinThread indx

      SYSTEM

    NEXT

  END IF



  FOR indx = 0 TO tc

    _PRINTSTRING (indx * 100 + 10, 220), "Worker:" + STR$(indx)

    _PUTIMAGE (indx * 100, 250), worker(indx).sc

  NEXT



  _PRINTSTRING (10, 380), "Press 'd' toggle thread slowdown. Press 's' to start/stop threads. Press 'ESC' to exit."

  _LIMIT 60

  _DISPLAY

LOOP



SUB resetWorker (id AS LONG)

  worker(id).xsize = 100

  worker(id).ysize = 100

  worker(id).xstart = 0

  worker(id).ystart = 0

  worker(id).x = worker(id).xstart

  worker(id).y = worker(id).ystart

  worker(id).xsize = 100

  worker(id).ysize = 100

  worker(id).xdir = 1

  worker(id).colour = _RGB32(RND * 255, RND * 255, RND * 255)

END SUB



SUB workerThread (id AS LONG)

  DIM AS INTEGER dly



  DO

    lockThread id

    IF worker(id).x + worker(id).xdir > worker(id).xstart + worker(id).xsize OR worker(id).x + worker(id).xdir < worker(id).xstart THEN

      worker(id).xdir = -worker(id).xdir

      IF worker(id).y + 1 > worker(id).ysize THEN

        resetWorker id

      ELSE

        worker(id).y = worker(id).y + 1

      END IF

    ELSE

      worker(id).x = worker(id).x + worker(id).xdir

    END IF



    worker(id).offset = worker(id).img.OFFSET + (worker(id).x * 4) + (worker(id).y * worker(id).xsize * 4)

    _MEMPUT worker(id).img, worker(id).offset + 0, _BLUE32(worker(id).colour) AS _UNSIGNED _BYTE

    _MEMPUT worker(id).img, worker(id).offset + 1, _GREEN32(worker(id).colour) AS _UNSIGNED _BYTE

    _MEMPUT worker(id).img, worker(id).offset + 2, _RED32(worker(id).colour) AS _UNSIGNED _BYTE

    _MEMPUT worker(id).img, worker(id).offset + 3, 255 AS _UNSIGNED _BYTE



    IF NOT worker(id).dly THEN dly = 0: DO: dly = dly + 1: LOOP UNTIL dly < 0

    unlockThread id



  LOOP WHILE worker(id).command = 0

  exitThread

END SUB