Logging 在Windows中，使用PyQt4和PySide从QThread记录内存泄漏，而不是从Python线程记录

在QThread中使用“logging”模块时，我看到在Windows中运行时内存泄漏。在Python3中使用PySide和PyQt4都会发生这种情况

在Linux中，没有内存泄漏

下面的程序演示了这个问题。它可以用三种方式调用

在没有参数的情况下运行会使用Python线程，并且不会出现泄漏：

D:\> python MemoryLeak.py
gc objects: 8965
WARNING:root:hi there!
gc objects: 8987
WARNING:root:hi there!
gc objects: 8987
WARNING:root:hi there!
gc objects: 8987
WARNING:root:hi there!
(... etcetera ...)

使用单个“-qt”参数运行时，通过Qt4使用QThreads，在Windows中使用泄漏，但在Linux中不使用：

D:\>python MemoryLeak.py  --qt
gc objects: 8975
WARNING:root:hi there!
gc objects: 9000
WARNING:root:hi there!
gc objects: 9010
WARNING:root:hi there!
gc objects: 9020
WARNING:root:hi there!
gc objects: 9030
WARNING:root:hi there!
gc objects: 9040
WARNING:root:hi there!
(... etcetera ...)

D:\>python MemoryLeak.py  --qt --pyside
gc objects: 15076
WARNING:root:hi there!
gc objects: 15093
WARNING:root:hi there!
gc objects: 15103
WARNING:root:hi there!
gc objects: 15113
WARNING:root:hi there!
gc objects: 15123
WARNING:root:hi there!
gc objects: 15133
WARNING:root:hi there!
gc objects: 15143
(... etcetera...)

使用“-qt”和“-pyside”参数运行时，通过pyside使用QThreads，在Windows中使用漏洞，但在Linux中不使用：

D:\>python MemoryLeak.py  --qt
gc objects: 8975
WARNING:root:hi there!
gc objects: 9000
WARNING:root:hi there!
gc objects: 9010
WARNING:root:hi there!
gc objects: 9020
WARNING:root:hi there!
gc objects: 9030
WARNING:root:hi there!
gc objects: 9040
WARNING:root:hi there!
(... etcetera ...)

D:\>python MemoryLeak.py  --qt --pyside
gc objects: 15076
WARNING:root:hi there!
gc objects: 15093
WARNING:root:hi there!
gc objects: 15103
WARNING:root:hi there!
gc objects: 15113
WARNING:root:hi there!
gc objects: 15123
WARNING:root:hi there!
gc objects: 15133
WARNING:root:hi there!
gc objects: 15143
(... etcetera...)

我在Windows下使用的是基于Python 3.3.5的WinPython 3.3.5

我的完整测试计划：

#! /usr/bin/env python3

import sys, time, logging, gc, threading

if "--pyside" in sys.argv:
    from PySide import QtCore
    QtSlot = QtCore.Slot
else:
    from PyQt4 import QtCore
    QtSlot = QtCore.pyqtSlot

def gc_status():
    gc.collect(0)
    gc.collect(1)
    gc.collect(2)
    print("gc objects:", len(gc.get_objects()))

class MyQtThread(QtCore.QThread):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
    def run(self):
        logging.warning("hi there!")

class MyQtApplication(QtCore.QCoreApplication):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self._count = 0
        self._timer = QtCore.QTimer()
        self._timer.timeout.connect(self._timer_timeout)
        self._timer.start(200)

    @QtSlot()
    def _timer_timeout(self):
        gc_status()
        t = MyQtThread()
        t.start()
        t.wait()
        self._count += 1
        if self._count == 50:
            self.quit()

def qt_main():
    app = MyQtApplication(sys.argv)
    app.exec_()

class PythonThread(threading.Thread):
    def __init__(self):
        super().__init__()
    def run(self):
        logging.warning("hi there!")

def python_main():
    for i in range(50):
        gc_status()
        t = PythonThread()
        t.start()
        t.join()
        time.sleep(0.200)

if "--qt" in sys.argv:
    qt_main()
else:
    python_main()

---

这是一个已知的问题/错误吗？还是我做错了什么？

我刚刚尝试了Python2.7（最新的PyQt4）并看到了同样的结果。我认为这可能是日志模块的问题，而不是PyQt/PySide的问题。我分析了泄漏的内容，它是一堆Python字典和列表，因此我猜如果在Python线程之外使用日志模块，日志模块不知道如何清理它自己。我在Windows 7上的Python 3.4.2 64位上尝试了PySide 1.2.2，但没有发现泄漏。