python - 在Python(pyrasite)中检查线程中的局部变量？

Question

我有一个使用线程的脚本，该脚本在运行一个小时左右后便会冻结，这使得调试非常困难。

最终，我找到了pyrasite，基本上，等到它冻结后，我就可以“钩”入脚本。在终端中看起来像这样:

$ pyrasite-shell 3437
Pyrasite Shell 2.0
Connected to 'python3 code/MyTestScript.py'
Python 3.5.3 (default, Sep 27 2018, 17:25:39)
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
(DistantInteractiveConsole)

>>> import sys, traceback
>>> for thread_id, frame in sys._current_frames().items():
...     print('Stack for thread {}'.format(thread_id))
...     traceback.print_stack(frame)
...     print('')
...
Stack for thread 1888482416
  File "/usr/lib/python3.5/threading.py", line 882, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "<string>", line 167, in run
  File "/usr/lib/python3.5/code.py", line 228, in interact
    more = self.push(line)
  File "/usr/lib/python3.5/code.py", line 250, in push
    more = self.runsource(source, self.filename)
  File "/usr/lib/python3.5/code.py", line 75, in runsource
    self.runcode(code)
  File "/usr/lib/python3.5/code.py", line 91, in runcode
    exec(code, self.locals)
  File "<console>", line 3, in <module>

Stack for thread 1898968176
  File "/usr/lib/python3.5/threading.py", line 882, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.5/threading.py", line 862, in run
    self._target(*self._args, **self._kwargs)
  File "/home/pi/code/my_test_lib.py", line 187, in sendData
    self.evexit.wait(sleep_time_s)
  File "/usr/lib/python3.5/threading.py", line 549, in wait
    signaled = self._cond.wait(timeout)
  File "/usr/lib/python3.5/threading.py", line 297, in wait
    gotit = waiter.acquire(True, timeout)

Stack for thread 1996019264
  File "code/MyTestScript.py", line 1355, in <module>
    main(sys.argv[1:])
  File "code/MyTestScript.py", line 1245, in main
    myObject.waitForJoin() # seems to work fine...
  File "/home/pi/code/my_test_lib.py", line 251, in waitForJoin
    self.myThread.join()
  File "/usr/lib/python3.5/threading.py", line 1054, in join
    self._wait_for_tstate_lock()
  File "/usr/lib/python3.5/threading.py", line 1070, in _wait_for_tstate_lock
    elif lock.acquire(block, timeout):

Stack for thread 1908950128
  File "/usr/lib/python3.5/threading.py", line 882, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.5/threading.py", line 862, in run
    self._target(*self._args, **self._kwargs)
  File "/home/pi/code/my_testB_lib.py", line 511, in UpdateMyThread
    time.sleep(_update_interval_sec)

这看起来不错，但我无法确定的是，包括其所有线程的脚本现在是否已暂停(好像已在 gdb中设置了断点)，还是该脚本一直在后台运行？

无论如何，我知道在 gdb中，我可以刚刚发出 thread 1，然后结束于相应的堆栈帧，然后可以打印局部变量等。

但是，在这里，我无法告诉您如何更改堆栈框架，也不能告诉您如何切换线程，以便可以检查变量。
pyrasite是否可能？如果没有，那么是否还有其他适用于Python3的库，这将使我具有相同的库(即能够冻结具有冻结线程的未插入脚本的能力)，同时允许我检查任何/所有线程和堆栈框架中的局部变量值？

Answer 1

从Pyrasite包含的dump_stacks.py有效内容开始，我创建了以下代码段，该代码段在每次堆栈跟踪之后转储局部变量名称和值。但是，它似乎不能作为Pyrasite负载正常工作-看起来由于某些原因而显示了全局变量吗？我本人是Pyrasite的新手，所以不确定这是Bug还是使用不正确。如果我改为运行pyrasite-shell并直接将代码粘贴到其中，则它将按预期工作(忽略了来自 shell 线程本身的额外跟踪)。

如果您需要查看其他信息，则可以修改代码并重新粘贴，或者仅在吡硫铁矿 shell 中进行交互浏览。

import sys, traceback

for thread, frame in sys._current_frames().items():
    print('Thread 0x%x' % thread)
    print('=' * 25)
    traceback.print_stack(frame)
    print('-' * 25)
    for name, value in frame.f_locals.items():
        print(f"{name}: {value}")
    print()