diff options
| -rw-r--r-- | Demo/tkinter/guido/brownian.py | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/Demo/tkinter/guido/brownian.py b/Demo/tkinter/guido/brownian.py index ec3dbef..b08a956 100644 --- a/Demo/tkinter/guido/brownian.py +++ b/Demo/tkinter/guido/brownian.py @@ -1,4 +1,4 @@ -# An example of a multi-threaded Tkinter program. +# Brownian motion -- an example of a multi-threaded Tkinter program. from Tkinter import * import random @@ -14,22 +14,35 @@ RADIUS = 2 LAMBDA = 10 FILL = 'red' +stop = 0 # Set when main loop exits + +lock = threading.Lock() # Protects the random generator + def particle(canvas): r = RADIUS - x = random.gauss(WIDTH/2.0, SIGMA) - y = random.gauss(HEIGHT/2.0, SIGMA) + lock.acquire() + try: + x = random.gauss(WIDTH/2.0, SIGMA) + y = random.gauss(HEIGHT/2.0, SIGMA) + finally: + lock.release() p = canvas.create_oval(x-r, y-r, x+r, y+r, fill=FILL) - while 1: - dx = random.gauss(0, BUZZ) - dy = random.gauss(0, BUZZ) + while not stop: + lock.acquire() + try: + dx = random.gauss(0, BUZZ) + dy = random.gauss(0, BUZZ) + dt = random.expovariate(LAMBDA) + finally: + lock.release() try: canvas.move(p, dx, dy) except TclError: break - dt = random.expovariate(LAMBDA) time.sleep(dt) def main(): + global stop root = Tk() canvas = Canvas(root, width=WIDTH, height=HEIGHT) canvas.pack(fill='both', expand=1) @@ -39,6 +52,9 @@ def main(): for i in range(np): t = threading.Thread(target=particle, args=(canvas,)) t.start() - root.mainloop() + try: + root.mainloop() + finally: + stop = 1 main() |