joint_state_publisher on OSX

edit

When running joint_state_publisher on OSX Lion, I encounter the following error

[INFO] [WallTime: 1335373686.654959] Centering
2012-04-25 10:08:06.886 Python[41356:450b] *** Assertion failure in +[NSUndoManager _endTopLevelGroupings], /SourceCache/Foundation/Foundation-833.24/Misc.subproj/NSUndoManager.m:324
2012-04-25 10:08:06.888 Python[41356:450b] +[NSUndoManager(NSInternal) _endTopLevelGroupings] is only safe to invoke on the main thread.
2012-04-25 10:08:06.901 Python[41356:450b] (
    0   CoreFoundation                      0x00007fff8c261fc6 __exceptionPreprocess + 198
    1   libobjc.A.dylib                     0x00007fff9040dd5e objc_exception_throw + 43
    2   CoreFoundation                      0x00007fff8c261dfa +[NSException raise:format:arguments:] + 106
    3   Foundation                          0x00007fff93a7c743 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 169
    4   Foundation                          0x00007fff939eb983 +[NSUndoManager(NSPrivate) _endTopLevelGroupings] + 144
    5   AppKit                              0x00007fff8df2721b -[NSApplication run] + 596
    6   libwx_osx_cocoau_core-2.9.dylib     0x000000010d637e20 _ZN14wxGUIEventLoop5DoRunEv + 44
    7   libwx_baseu-2.9.dylib               0x000000010dbebf79 _ZN13wxCFEventLoop3RunEv + 63
    8   libwx_baseu-2.9.dylib               0x000000010db3cd97 _ZN16wxAppConsoleBase8MainLoopEv + 81
    9   _core_.so                           0x000000010cfa5619 _ZN7wxPyApp8MainLoopEv + 81
    10  _core_.so                           0x000000010cfc1c2b _wrap_PyApp_MainLoop + 235
    11  Python                              0x000000010c5315d8 PyEval_EvalFrameEx + 16006
    12  Python                              0x000000010c533cd8 PyEval_EvalCodeEx + 1996
    13  Python                              0x000000010c4d1abf PyClassMethod_New + 1378
    14  Python                              0x000000010c4b0d32 PyObject_Call + 97
    15  Python                              0x000000010c4bf6e9 PyInstance_New + 13169
    16  Python                              0x000000010c4b0d32 PyObject_Call + 97
    17  Python                              0x000000010c530f63 PyEval_EvalFrameEx + 14353
    18  Python                              0x000000010c533cd8 PyEval_EvalCodeEx + 1996
    19  Python                              0x000000010c4d1abf PyClassMethod_New + 1378
    20  Python                              0x000000010c4b0d32 PyObject_Call + 97
    21  Python                              0x000000010c5315ec PyEval_EvalFrameEx + 16026
    22  Python                              0x000000010c533df7 PyEval_EvalCode + 224
    23  Python                              0x000000010c530e0a PyEval_EvalFrameEx + 14008
    24  Python                              0x000000010c533df7 PyEval_EvalCode + 224
    25  Python                              0x000000010c530e0a PyEval_EvalFrameEx + 14008
    26  Python                              0x000000010c533cd8 PyEval_EvalCodeEx + 1996
    27  Python                              0x000000010c4d1abf PyClassMethod_New + 1378
    28  Python                              0x000000010c4b0d32 PyObject_Call + 97
    29  Python                              0x000000010c4bf6e9 PyInstance_New + 13169
    30  Python                              0x000000010c4b0d32 PyObject_Call + 97
    31  Python                              0x000000010c52cc40 PyEval_CallObjectWithKeywords + 180
    32  Python                              0x000000010c55e40d initthread + 2629
    33  libsystem_c.dylib                   0x00007fff9074b8bf _pthread_start + 335
    34  libsystem_c.dylib                   0x00007fff9074eb75 thread_start + 13
)

After some google search, it appears the issue that in newer Cocoa/Lion, it requires the "App.MainLoop" run in the same thread as the thread who initialize the wx. In joint state publisher, the App.MainLoop is run by a newly created thread while the main thread is used to send out joint_state messages..

Here I provide an workaround that swap these two threads,

diff -r 655f14965dbc joint_state_publisher/joint_state_publisher
--- a/joint_state_publisher/joint_state_publisher   Wed Jun 01 14:37:58 2011 -0700
+++ b/joint_state_publisher/joint_state_publisher   Wed Apr 25 10:00:03 2012 -0700
@@ -58,10 +58,10 @@
         use_gui = get_param("use_gui", False)

         if use_gui:
-            app = wx.App()
+            self.app = wx.App()
             self.gui = JointStatePublisherGui("Joint State Publisher", self)
             self.gui.Show()
-            Thread(target=app.MainLoop).start()
         else:
             self.gui = None

@@ -200,7 +203,8 @@
     try:
         rospy.init_node('joint_state_publisher')
         jsp = JointStatePublisher()
-        jsp.loop()
+        Thread(target=jsp.loop).start()
+        jsp.app.MainLoop()

     except rospy.ROSInterruptException: pass

Here's a minimum set of code to generate the same crash

def gui():
        import wx
        app = wx.App()
        frame = wx.Frame(None)
        frame.Show()
        app.MainLoop()
import threading
threading.Thread(target=gui).start()