尝试通过发送进程 运行 Tkinter 在进程之间通过管道发送任何内容时发生管道错误
Broken pipe error when trying to send anything over pipe between processes with sending process running Tkinter
我正在使用 multiprocessing 模块 (Python 3.8) 中的 Pipe 和 Process。我的初始程序如下所示：
from multiprocessing import Process, Pipe
class Process1(object):
def __init__(self, pipe_out):
self.pipe_out = pipe_out
self.run()
def run(self):
try:
while True:
print("Sending message to process 2")
self.pipe_out.send(["hello"])
except KeyboardInterrupt:
pass
class Process2(object):
def __init__(self, pipe_in):
self.pipe_in = pipe_in
self.run()
def run(self):
try:
while self.pipe_in.poll():
request = self.pipe_in.recv()
method = request[0]
args = request[1:]
try:
getattr(self, method + "_callback")(*args)
except AttributeError as ae:
print("Unknown callback received from pipe", str(ae))
print("Process 2 done with receiving")
except KeyboardInterrupt:
pass
def hello_callback(self):
print("Process 1 said hello")
class Controller(object):
def __init__(self):
pipe_proc1_out, pipe_proc2_in = Pipe()
self.proc1 = Process(
target=Process1,
args=(pipe_proc1_out, )
)
self.proc2 = Process(
target=Process2,
args=(pipe_proc2_in, )
)
def run(self):
try:
self.proc1.start()
self.proc2.start()
while True:
continue
except KeyboardInterrupt:
print("Quitting processes...")
self.proc1.join(1)
if self.proc1.is_alive():
self.proc1.terminate()
self.proc2.join(1)
if self.proc2.is_alive():
self.proc2.terminate()
print("Finished")
def pipes():
c = Controller()
c.run()
if __name__ == "__main__":
pipes()
我有一个 Controller 实例，它一直运行到收到键盘中断为止。它还处理Process1和Process2两个进程，前者不断发送，后者不断接收。
上面的代码是涉及复杂 GUI (PySide)、图像处理 (OpenCV) 和游戏引擎 (Panda3D) 的更大项目的框架。所以我尝试将 Tkinter 添加为 GUI 示例：
from multiprocessing import Process, Pipe
import tkinter as tk
class Process1(tk.Frame):
def __init__(self, pipe_out):
self.pipe_out = pipe_out
self.setup_gui()
self.run()
def setup_gui(self):
self.app = tk.Tk()
lb1 = tk.Label(self.app, text="Message:")
lb1.pack()
self.ent1 = tk.Entry(self.app)
self.ent1.pack()
btn1 = tk.Button(self.app, text="Say hello to other process",
command=self.btn1_clicked)
btn1.pack()
def btn1_clicked(self):
msg = self.ent1.get()
self.pipe_out.send(["hello", msg])
def run(self):
try:
self.app.mainloop()
except KeyboardInterrupt:
pass
class Process2(object):
def __init__(self, pipe_in):
self.pipe_in = pipe_in
self.run()
def run(self):
try:
while self.pipe_in.poll():
request = self.pipe_in.recv()
method = request[0]
args = request[1:]
try:
getattr(self, method + "_callback")(*args)
except AttributeError as ae:
print("Unknown callback received from pipe", str(ae))
print("Process 2 done with receiving")
except KeyboardInterrupt:
pass
def hello_callback(self, msg):
print("Process 1 say\"" + msg + "\"")
class Controller(object):
def __init__(self):
pipe_proc1_out, pipe_proc2_in = Pipe()
self.proc1 = Process(
target=Process1,
args=(pipe_proc1_out, )
)
self.proc2 = Process(
target=Process2,
args=(pipe_proc2_in, )
)
def run(self):
try:
self.proc1.start()
self.proc2.start()
while True:
continue
except KeyboardInterrupt:
print("Quitting processes...")
self.proc1.join(1)
if self.proc1.is_alive():
self.proc1.terminate()
self.proc2.join(1)
if self.proc2.is_alive():
self.proc2.terminate()
print("Finished")
def pipes():
c = Controller()
c.run()
if __name__ == "__main__":
pipes()
请注意，目前 Tkinter window 只有在“父”进程通过键盘中断时才能关闭。
每当我单击按钮并调用按钮的命令时，我的程序都会进入错误状态并显示以下消息：
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\USER\Anaconda3\envs\THS\lib\tkinter\__init__.py", line 1705, in __call__
return self.func(*args)
File "C:\Users\USER\PycharmProjects\PythonPlayground\pipes_advanced.py", line 26, in btn1_clicked
self.pipe_out.send(["hello", 1, 2])
File "C:\Users\USER\Anaconda3\envs\THS\lib\multiprocessing\connection.py", line 206, in send
self._send_bytes(_ForkingPickler.dumps(obj))
File "C:\Users\USER\Anaconda3\envs\THS\lib\multiprocessing\connection.py", line 280, in _send_bytes
ov, err = _winapi.WriteFile(self._handle, buf, overlapped=True)
BrokenPipeError: [WinError 232] The pipe is being closed
起初我认为问题出在我从 Entry.get() 调用中收到的值（我的 Tkinter 技能生锈了）。我打印了 msg 并从小部件中获取了文本。
接下来我尝试的是将常量字符串作为我通过管道发送的参数的值：
def btn1_clicked(self):
self.pipe_out.send(["hello", "world"])
出现同样的错误。捕获异常 BrokenPipeError 对我没有任何好处（除非我想处理管道坏了的情况）。
如果我对程序的第一个版本（没有 Tkinter）执行相同的操作，它就可以工作。这让我相信我的问题来自于我集成 Tkinter 的方式。
您遇到的问题是您轮询管道，但 documentation 说：
poll([timeout])
Return whether there is any data available to be read.
If timeout is not specified then it will return immediately.
在第一个示例中，它起作用了，因为当启动时 Process1 您立即将数据发送到管道：
def run(self):
try:
while True:
print("Sending message to process 2")
self.pipe_out.send(["hello"])
except KeyboardInterrupt:
pass
并且你不断地这样做，所以 .poll 将 return True 并且 Process2 中的循环将继续。
与 tkinter 一样，它等待用户单击按钮时不会立即将任何内容发送到管道，到任何可能发生的时候 Process2 已经调用了 poll它立即 returned False 并且它甚至没有启动该循环。如果您注意到它也会立即在终端中打印
"Process 2 done with receiving"
解决这个问题最简单的方法似乎是
while self.pipe_in.poll(None):
根据文档的意思
"If timeout is None then an infinite timeout is used."
对于用户界面之类的东西，这似乎是最合适的（至少从用户的角度来看（或者我认为））所以基本上 Process2 中的 run 方法应该是这样的:
def run(self):
try:
while self.pipe_in.poll(None):
request = self.pipe_in.recv()
method = request[0]
args = request[1:]
try:
getattr(self, method + "_callback")(*args)
except AttributeError as ae:
print("Unknown callback received from pipe", str(ae))
print("Process 2 done with receiving")
except (KeyboardInterrupt, EOFError):
pass
也与问题无关，但似乎没有必要继承Process1中的tk.Frame（或Process2中的object（除非你真的需要使其与 Python2)) 兼容，你几乎可以从 tk.Tk 继承，这应该使它更容易实际用作主要 window，因为 self 将是Tk实例
我正在使用 multiprocessing 模块 (Python 3.8) 中的 Pipe 和 Process。我的初始程序如下所示：
from multiprocessing import Process, Pipe
class Process1(object):
def __init__(self, pipe_out):
self.pipe_out = pipe_out
self.run()
def run(self):
try:
while True:
print("Sending message to process 2")
self.pipe_out.send(["hello"])
except KeyboardInterrupt:
pass
class Process2(object):
def __init__(self, pipe_in):
self.pipe_in = pipe_in
self.run()
def run(self):
try:
while self.pipe_in.poll():
request = self.pipe_in.recv()
method = request[0]
args = request[1:]
try:
getattr(self, method + "_callback")(*args)
except AttributeError as ae:
print("Unknown callback received from pipe", str(ae))
print("Process 2 done with receiving")
except KeyboardInterrupt:
pass
def hello_callback(self):
print("Process 1 said hello")
class Controller(object):
def __init__(self):
pipe_proc1_out, pipe_proc2_in = Pipe()
self.proc1 = Process(
target=Process1,
args=(pipe_proc1_out, )
)
self.proc2 = Process(
target=Process2,
args=(pipe_proc2_in, )
)
def run(self):
try:
self.proc1.start()
self.proc2.start()
while True:
continue
except KeyboardInterrupt:
print("Quitting processes...")
self.proc1.join(1)
if self.proc1.is_alive():
self.proc1.terminate()
self.proc2.join(1)
if self.proc2.is_alive():
self.proc2.terminate()
print("Finished")
def pipes():
c = Controller()
c.run()
if __name__ == "__main__":
pipes()
我有一个 Controller 实例，它一直运行到收到键盘中断为止。它还处理Process1和Process2两个进程，前者不断发送，后者不断接收。
上面的代码是涉及复杂 GUI (PySide)、图像处理 (OpenCV) 和游戏引擎 (Panda3D) 的更大项目的框架。所以我尝试将 Tkinter 添加为 GUI 示例：
from multiprocessing import Process, Pipe
import tkinter as tk
class Process1(tk.Frame):
def __init__(self, pipe_out):
self.pipe_out = pipe_out
self.setup_gui()
self.run()
def setup_gui(self):
self.app = tk.Tk()
lb1 = tk.Label(self.app, text="Message:")
lb1.pack()
self.ent1 = tk.Entry(self.app)
self.ent1.pack()
btn1 = tk.Button(self.app, text="Say hello to other process",
command=self.btn1_clicked)
btn1.pack()
def btn1_clicked(self):
msg = self.ent1.get()
self.pipe_out.send(["hello", msg])
def run(self):
try:
self.app.mainloop()
except KeyboardInterrupt:
pass
class Process2(object):
def __init__(self, pipe_in):
self.pipe_in = pipe_in
self.run()
def run(self):
try:
while self.pipe_in.poll():
request = self.pipe_in.recv()
method = request[0]
args = request[1:]
try:
getattr(self, method + "_callback")(*args)
except AttributeError as ae:
print("Unknown callback received from pipe", str(ae))
print("Process 2 done with receiving")
except KeyboardInterrupt:
pass
def hello_callback(self, msg):
print("Process 1 say\"" + msg + "\"")
class Controller(object):
def __init__(self):
pipe_proc1_out, pipe_proc2_in = Pipe()
self.proc1 = Process(
target=Process1,
args=(pipe_proc1_out, )
)
self.proc2 = Process(
target=Process2,
args=(pipe_proc2_in, )
)
def run(self):
try:
self.proc1.start()
self.proc2.start()
while True:
continue
except KeyboardInterrupt:
print("Quitting processes...")
self.proc1.join(1)
if self.proc1.is_alive():
self.proc1.terminate()
self.proc2.join(1)
if self.proc2.is_alive():
self.proc2.terminate()
print("Finished")
def pipes():
c = Controller()
c.run()
if __name__ == "__main__":
pipes()
请注意，目前 Tkinter window 只有在“父”进程通过键盘中断时才能关闭。
每当我单击按钮并调用按钮的命令时，我的程序都会进入错误状态并显示以下消息：
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\USER\Anaconda3\envs\THS\lib\tkinter\__init__.py", line 1705, in __call__
return self.func(*args)
File "C:\Users\USER\PycharmProjects\PythonPlayground\pipes_advanced.py", line 26, in btn1_clicked
self.pipe_out.send(["hello", 1, 2])
File "C:\Users\USER\Anaconda3\envs\THS\lib\multiprocessing\connection.py", line 206, in send
self._send_bytes(_ForkingPickler.dumps(obj))
File "C:\Users\USER\Anaconda3\envs\THS\lib\multiprocessing\connection.py", line 280, in _send_bytes
ov, err = _winapi.WriteFile(self._handle, buf, overlapped=True)
BrokenPipeError: [WinError 232] The pipe is being closed
起初我认为问题出在我从 Entry.get() 调用中收到的值（我的 Tkinter 技能生锈了）。我打印了 msg 并从小部件中获取了文本。
接下来我尝试的是将常量字符串作为我通过管道发送的参数的值：
def btn1_clicked(self):
self.pipe_out.send(["hello", "world"])
出现同样的错误。捕获异常 BrokenPipeError 对我没有任何好处（除非我想处理管道坏了的情况）。
如果我对程序的第一个版本（没有 Tkinter）执行相同的操作，它就可以工作。这让我相信我的问题来自于我集成 Tkinter 的方式。
您遇到的问题是您轮询管道，但 documentation 说：
poll([timeout])
Return whether there is any data available to be read.
If timeout is not specified then it will return immediately.
在第一个示例中，它起作用了，因为当启动时 Process1 您立即将数据发送到管道：
def run(self):
try:
while True:
print("Sending message to process 2")
self.pipe_out.send(["hello"])
except KeyboardInterrupt:
pass
并且你不断地这样做，所以 .poll 将 return True 并且 Process2 中的循环将继续。
与 tkinter 一样，它等待用户单击按钮时不会立即将任何内容发送到管道，到任何可能发生的时候 Process2 已经调用了 poll它立即 returned False 并且它甚至没有启动该循环。如果您注意到它也会立即在终端中打印
"Process 2 done with receiving"
解决这个问题最简单的方法似乎是
while self.pipe_in.poll(None):
根据文档的意思
"If timeout is None then an infinite timeout is used."
对于用户界面之类的东西，这似乎是最合适的（至少从用户的角度来看（或者我认为））所以基本上 Process2 中的 run 方法应该是这样的:
def run(self):
try:
while self.pipe_in.poll(None):
request = self.pipe_in.recv()
method = request[0]
args = request[1:]
try:
getattr(self, method + "_callback")(*args)
except AttributeError as ae:
print("Unknown callback received from pipe", str(ae))
print("Process 2 done with receiving")
except (KeyboardInterrupt, EOFError):
pass
也与问题无关，但似乎没有必要继承Process1中的tk.Frame（或Process2中的object（除非你真的需要使其与 Python2)) 兼容，你几乎可以从 tk.Tk 继承，这应该使它更容易实际用作主要 window，因为 self 将是Tk实例