在PyGObject内省中，线程在GTK w / Python中有变化吗？ [英] Has threading in GTK w/ Python changed in PyGObject introspection?

问题描述

我第一次正在将一个程序从PyGTK转换为PyGObject内省，并且我已经通过线程攻击了一个障碍。我有一个需要一些时间才能完成的过程，所以我弹出一个对话框，其上有一个进度条，我使用一个线程来完成该过程并更新进度条。这在PyGTK中运行良好，但在转换为PyGObject之后，我得到了所有不正常的线程怪异：程序挂起，但它似乎挂在进程的不同部分等等。所以我得到的印象是某些东西已经改变，但我可以不知道是什么。

以下是这个简单的PyGTK进度条示例： http://aruiz.typepad.com/siliconisland/2006/04/threads_on_pygt.html
如该页面所示，代码有效。我已经将它转换为PyGObject introspection，并且遇到了与我的程序中相同的问题：它挂起，没有正确更新进度条等。

 导入线程
导入随机，时间
 from gi.repository import Gtk，Gdk 
＃初始化gtk的线程引擎
 Gdk.threads_init（）
 
 
 class FractionSetter（threading.Thread）：
这个类设置进度条的小数部分
 
 #Thread事件，停止该线程是否已设置。 
 stopthread = threading.Event（）
 
 def run（self）：
运行方法，这是运行线程时运行的代码。
 
＃从全局范围导入进度条小部件
全局进度条
 
＃当stopthread事件未设置时，线程继续执行
 not self.stopthread.isSet（）：
＃获取gtk全局互斥量
 Gdk.threads_enter（）
＃为分数
设置一个随机值progressbar.set_fraction（random。随机（））
＃释放gtk全局互斥
 Gdk.threads_leave（）
 
＃延迟100ms直到下一次迭代
 time.sleep（0.1）
 
 def stop（self）：
停止方法，设置事件以终止线程的主循环
 self.stopthread.set（）
 
 def main_quit（obj）：
main_quit函数， t停止线程和gtk的主循环
＃从全局范围导入fs对象
全局fs 
＃停止线程和gtk的主循环
 fs。 stop（）
 Gtk.main_quit（）
 
 #Gui bootstrap：窗口和进度条
 window = Gtk.Window（）
 progressbar = Gtk.ProgressBar（）
 window.add（progressbar）
 window.show_all（）
＃将'destroy'事件连接到main_quit函数
 window.connect（'destroy'，main_quit）
 
＃创建和启动线程
 fs = FractionSetter（）
 fs.start（）
 
 Gtk.main（）
  
 
 
  >>> from gi.repository import GLib 
>>> GLib.thread_init（无）
 Traceback（最近一次调用的最后一个）：
在< module>中，第1行的文件< stdin> 
文件/usr/lib/python2.7/site-packages/gi/types.py，第44行，函数
返回info.invoke（* args）
 glib.GError ：找不到g_thread_init：`g_thread_init'：/usr/lib/libglib-2.0.so.0：undefined symbol：g_thread_init 
  
我认为这是因为额外的线程库没有链接。如果这是我的线程问题的原因，那我该如何使用GLib，就好像这些库已经链接了一样？
通过用Python编写的一些Gnome程序（Gnome Sudoku，在这种情况下，实际上帮了我几次时间）设法回答我自己的问题。
   技巧是你必须在你的代码开头调用 GObject.threads_init（），而不是 GLib.thread_init（）正如C文档所暗示的那样。 
I'm in the process of converting a program from PyGTK to PyGObject introspection for the first time and I've hit a roadblock with threading. I have a process that takes some time to complete, so I pop up a dialog with a progress bar on it and I use a thread to do the process and to update the progress bar. This worked fine with PyGTK but after converting to PyGObject, I get all the usual improper threading weirdness: the program hangs, but it seems to hang in different parts of the process, etc. So I get the impression that something has changed but I can't figure out what. 

Here's this simple PyGTK progressbar example: http://aruiz.typepad.com/siliconisland/2006/04/threads_on_pygt.html
As presented on that page, the code works. I've converted it to PyGObject introspection and I get the same problems as in  my program: it hangs, it doesn't properly update the progress bar, etc.
import threading
import random, time
from gi.repository import Gtk, Gdk
#Initializing the gtk's thread engine
Gdk.threads_init()


class FractionSetter(threading.Thread):
    """This class sets the fraction of the progressbar"""

    #Thread event, stops the thread if it is set.
    stopthread = threading.Event()

    def run(self):
        """Run method, this is the code that runs while thread is alive."""

        #Importing the progressbar widget from the global scope
        global progressbar 

        #While the stopthread event isn't setted, the thread keeps going on
        while not self.stopthread.isSet() :
            # Acquiring the gtk global mutex
            Gdk.threads_enter()
            #Setting a random value for the fraction
            progressbar.set_fraction(random.random())
            # Releasing the gtk global mutex
            Gdk.threads_leave()

            #Delaying 100ms until the next iteration
            time.sleep(0.1)

    def stop(self):
        """Stop method, sets the event to terminate the thread's main loop"""
        self.stopthread.set()

def main_quit(obj):
    """main_quit function, it stops the thread and the gtk's main loop"""
    #Importing the fs object from the global scope
    global fs
    #Stopping the thread and the gtk's main loop
    fs.stop()
    Gtk.main_quit()

#Gui bootstrap: window and progressbar
window = Gtk.Window()
progressbar = Gtk.ProgressBar()
window.add(progressbar)
window.show_all()
#Connecting the 'destroy' event to the main_quit function
window.connect('destroy', main_quit)

#Creating and starting the thread
fs = FractionSetter()
fs.start()

Gtk.main()
In the documentation for Gdk's threading capabilities, it stresses that you first must run g_thread_init(NULL) before running gdk_threads_init(). But to run that, you need to link in some extra libraries. If I try to import GLib through introspection and then I try to run GLib.thread_init(), I get the following error:
>>> from gi.repository import GLib
>>> GLib.thread_init(None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/site-packages/gi/types.py", line 44, in function
    return info.invoke(*args)
glib.GError: Could not locate g_thread_init: `g_thread_init': /usr/lib/libglib-2.0.so.0: undefined symbol: g_thread_init
I assume this is because the extra threading libraries weren't linked. If this is the cause of my threading problems, how can I work with GLib as if those libraries have been linked?
解决方案
I managed to answer my own question by poking through some Gnome programs written in Python (Gnome Sudoku, in this case, which actually has helped me a couple of times).

The trick is that you have to call GObject.threads_init() at the beginning of your code, not GLib.thread_init() as the C documentation implies.

                        
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