我尝试在tkinter应用程序中实现matplotlib图表，它工作正常，但在关闭主窗口（m）后，该过程仍在进行，并且无法在不关闭控制台的情况下停止它。为什么？

import matplotlib.backends.backend_tkagg as tkagg
import matplotlib.pyplot as plt
import matplotlib
import tkinter as tk
matplotlib.use('TkAgg')
def plot_canvas(master):
    points = [(0, 0), (10, 0), (10, 25), (20, 25), (25, 0)]
    fig = plt.figure(figsize=(5, 4))
    fig.add_subplot(111).plot([x[0] for x in points],
                              [x[1] for x in points],
                              marker='.',
                              linestyle='-')
    # ax.
    # ax.plot([10, 20], [25, 25], marker='.', linestyle=':', color='green')
    return tkagg.FigureCanvasTkAgg(fig, master=master).get_tk_widget()
m = tk.Tk()
wgt = plot_canvas(m)
wgt.grid()
m.mainloop()