Remove the Event '_triggered' in osx.py to fix hangs. (#14125)

This is my proposed fix for issue  #14072.

IPython/terminal/pt_inputhooks/osx.py

@@ -1,157 +1,147 b''
 """Inputhook for OS X
 
 Calls NSApp / CoreFoundation APIs via ctypes.
 """
 
 # obj-c boilerplate from appnope, used under BSD 2-clause
 
 import ctypes
 import ctypes.util
 from threading import Event
 
 objc = ctypes.cdll.LoadLibrary(ctypes.util.find_library("objc"))  # type: ignore
 
 void_p = ctypes.c_void_p
 
 objc.objc_getClass.restype = void_p
 objc.sel_registerName.restype = void_p
 objc.objc_msgSend.restype = void_p
 objc.objc_msgSend.argtypes = [void_p, void_p]
 
 msg = objc.objc_msgSend
 
 def _utf8(s):
     """ensure utf8 bytes"""
     if not isinstance(s, bytes):
         s = s.encode('utf8')
     return s
 
 def n(name):
     """create a selector name (for ObjC methods)"""
     return objc.sel_registerName(_utf8(name))
 
 def C(classname):
     """get an ObjC Class by name"""
     return objc.objc_getClass(_utf8(classname))
 
 # end obj-c boilerplate from appnope
 
 # CoreFoundation C-API calls we will use:
 CoreFoundation = ctypes.cdll.LoadLibrary(ctypes.util.find_library("CoreFoundation"))  # type: ignore
 
 CFFileDescriptorCreate = CoreFoundation.CFFileDescriptorCreate
 CFFileDescriptorCreate.restype = void_p
 CFFileDescriptorCreate.argtypes = [void_p, ctypes.c_int, ctypes.c_bool, void_p, void_p]
 
 CFFileDescriptorGetNativeDescriptor = CoreFoundation.CFFileDescriptorGetNativeDescriptor
 CFFileDescriptorGetNativeDescriptor.restype = ctypes.c_int
 CFFileDescriptorGetNativeDescriptor.argtypes = [void_p]
 
 CFFileDescriptorEnableCallBacks = CoreFoundation.CFFileDescriptorEnableCallBacks
 CFFileDescriptorEnableCallBacks.restype = None
 CFFileDescriptorEnableCallBacks.argtypes = [void_p, ctypes.c_ulong]
 
 CFFileDescriptorCreateRunLoopSource = CoreFoundation.CFFileDescriptorCreateRunLoopSource
 CFFileDescriptorCreateRunLoopSource.restype = void_p
 CFFileDescriptorCreateRunLoopSource.argtypes = [void_p, void_p, void_p]
 
 CFRunLoopGetCurrent = CoreFoundation.CFRunLoopGetCurrent
 CFRunLoopGetCurrent.restype = void_p
 
 CFRunLoopAddSource = CoreFoundation.CFRunLoopAddSource
 CFRunLoopAddSource.restype = None
 CFRunLoopAddSource.argtypes = [void_p, void_p, void_p]
 
 CFRelease = CoreFoundation.CFRelease
 CFRelease.restype = None
 CFRelease.argtypes = [void_p]
 
 CFFileDescriptorInvalidate = CoreFoundation.CFFileDescriptorInvalidate
 CFFileDescriptorInvalidate.restype = None
 CFFileDescriptorInvalidate.argtypes = [void_p]
 
 # From CFFileDescriptor.h
 kCFFileDescriptorReadCallBack = 1
 kCFRunLoopCommonModes = void_p.in_dll(CoreFoundation, 'kCFRunLoopCommonModes')
 
 
 def _NSApp():
     """Return the global NSApplication instance (NSApp)"""
     objc.objc_msgSend.argtypes = [void_p, void_p]
     return msg(C('NSApplication'), n('sharedApplication'))
 
 
 def _wake(NSApp):
     """Wake the Application"""
     objc.objc_msgSend.argtypes = [
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
         void_p,
     ]
     event = msg(
         C("NSEvent"),
         n(
             "otherEventWithType:location:modifierFlags:"
             "timestamp:windowNumber:context:subtype:data1:data2:"
         ),
         15,  # Type
         0,  # location
         0,  # flags
         0,  # timestamp
         0,  # window
         None,  # context
         0,  # subtype
         0,  # data1
         0,  # data2
     )
     objc.objc_msgSend.argtypes = [void_p, void_p, void_p, void_p]
     msg(NSApp, n('postEvent:atStart:'), void_p(event), True)
 
 
-_triggered = Event()
-
 def _input_callback(fdref, flags, info):
     """Callback to fire when there's input to be read"""
-    _triggered.set()
     CFFileDescriptorInvalidate(fdref)
     CFRelease(fdref)
     NSApp = _NSApp()
     objc.objc_msgSend.argtypes = [void_p, void_p, void_p]
     msg(NSApp, n('stop:'), NSApp)
     _wake(NSApp)
 
 _c_callback_func_type = ctypes.CFUNCTYPE(None, void_p, void_p, void_p)
 _c_input_callback = _c_callback_func_type(_input_callback)
 
 
 def _stop_on_read(fd):
     """Register callback to stop eventloop when there's data on fd"""
-    _triggered.clear()
     fdref = CFFileDescriptorCreate(None, fd, False, _c_input_callback, None)
     CFFileDescriptorEnableCallBacks(fdref, kCFFileDescriptorReadCallBack)
     source = CFFileDescriptorCreateRunLoopSource(None, fdref, 0)
     loop = CFRunLoopGetCurrent()
     CFRunLoopAddSource(loop, source, kCFRunLoopCommonModes)
     CFRelease(source)
 
 
 def inputhook(context):
     """Inputhook for Cocoa (NSApp)"""
     NSApp = _NSApp()
     _stop_on_read(context.fileno())
     objc.objc_msgSend.argtypes = [void_p, void_p]
     msg(NSApp, n('run'))
-    if not _triggered.is_set():
-        # app closed without firing callback,
-        # probably due to last window being closed.
-        # Run the loop manually in this case,
-        # since there may be events still to process (#9734)
-        CoreFoundation.CFRunLoopRun()