invalid mode 'kCFRunLoopCommonModes'

Question

Created Apr ’20

Replies 34

Boosts 2

Views 24k

Participants 34

invalid mode 'kCFRunLoopCommonModes' provided to CFRunLoopRunSpecific - break on _CFRunLoopError_RunCalledWithInvalidMode to debug

I get this warning when I tap either of the switches shown below. I've tried capturing the switch state in a var and using that to trigger the do/catch statement but no joy. I've even tried pulling the do/catch into separate functions and I still get the warning. Has anybody else run into this and how did you fix it?

 @IBAction func greetingFormat_Tapped(_ sender: UISwitch)
    {
        let theQuery = theTable_Settings.filter(settingID == 1)
       
        if sender.isOn
        {
            do {
                if try Database.shared.databaseConnection!.run(theQuery.update(greeting_Format <- "true")) > 0
                {
                    greetingFormatLabel_Outlet.text = NSLocalizedString("HelloMrSmith_String", comment: "")
                } else {
                    print("greeting format true not found")
                }
            } catch {
                print("greeting format true update failed! Error: \(error)")
            }
        } else {
            do {
                if try Database.shared.databaseConnection!.run(theQuery.update(greeting_Format <- "false")) > 0
                {
                    greetingFormatLabel_Outlet.text = NSLocalizedString("HiJoe_String", comment: "")
                } else {
                    print("greeting format false not found")
                }
            } catch {
                print("greeting format false update failed! Error: \(error)")
            }
        }
    }

 @IBAction func nonrefundableSwitch_Tapped(_ sender: UISwitch)
    {
        let theQuery = theTable_Settings.filter(settingID == 1)
        var itsOn: String = ""
       
        if sender.isOn
        {
            itsOn = "true"
        } else {
            itsOn = "false"
        }
       
        if itsOn == "true"
        {
            do {
                if try Database.shared.databaseConnection!.run(theQuery.update(nonRefundable_Bool <- "true")) > 0
                {
                    depositDueLabel_Outlet.text = NSLocalizedString("nonRefunddepositisdue_String", comment: "")
                } else {
                    print("nonRefundable true not found")
                }
            } catch {
                print("nonRefundable true update failed! Error: \(error)")
            }
        } else {
            do {
                if try Database.shared.databaseConnection!.run(theQuery.update(nonRefundable_Bool <- "false")) > 0
                {
                    depositDueLabel_Outlet.text = NSLocalizedString("depositisdue_String", comment: "")
                } else {
                    print("nonRefundable false not found")
                }
            } catch {
                print("nonRefundable false update failed! Error: \(error)")
            }
        }
    }

Boost

Answer 1

OOPer OP

Apr ’20

I created a simple sample project with only one UISwitch, its action connected to a method whch did nothing, and got exactly the same message.

2020-04-26 12:56:59.018799+0900 SwitchWarning[43358:4211342] invalid mode 'kCFRunLoopCommonModes' provided to CFRunLoopRunSpecific - break on _CFRunLoopError_RunCalledWithInvalidMode to debug. This message will only appear once per execution.

Do you have something unexpected after this message?

In my experience, I mark this sort of messages as ignorable (in my mind, not in Xcode menus) as far as my code works as expected.

0

Answer 2

quailcreek OP

Apr ’20

Thanks for the reply,

Nothing happens except the warning message. I even tried setting the switch action from "value changed" to "touch up inside", got the same warning. Looks to me like a glich with UISwitch.

0

Answer 3

Claude31 OP

Apr ’20

I had the same message some time ago and finally decided to ignore it.

It was also reported here:

https://stackoverflow.com/questions/56980875/what-does-invalid-mode-kcfrunloopcommonmodes-mean

Could be worth a bug report if not yet done.

0

Answer 4

DTS Engineer OP

Apple

Apr ’20

The common modes is a meta mode. If you schedule a run loop source in the common modes, the run loop schedules it in all modes that are marked as common (via

CFRunLoopAddCommonMode

). This allows you to schedule a source that runs in the default mode and, say, in the UI framework’s menu tracking mode.

However, when you run the run loop you must always run it in a specific mode. Running the run loop in the common modes is nonsensical, and if you try to do it you get this error.

The correct thing to do here is to set a symbolic breakpoint on

_CFRunLoopError_RunCalledWithInvalidMode

and then look at the backtrace to see who is doing this silliness.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

3

Answer 5

Claude31 OP

Apr ’20

So that's not a bug but a real programming error ?

Were typically, for a switch, would one set the correct mode ? And what is this correct mode ?

0

Answer 6

OOPer OP

Apr ’20

The correct thing to do here is to set a symbolic breakpoint on

_CFRunLoopError_RunCalledWithInvalidMode
and then look at the backtrace to see who is doing this silliness.

Of course I did it.

Thread 1 Queue : com.apple.main-thread (serial)

#0 0x00007fff23d9b6e0 in _CFRunLoopError_RunCalledWithInvalidMode ()

#1 0x000000010d390e8e in _dispatch_client_callout ()

#2 0x000000010d3923db in _dispatch_once_callout ()

#3 0x00007fff23d9b8f9 in CFRunLoopRunSpecific ()

#4 0x00007fff48601250 in __88-[UISwitchModernVisualElement _handleLongPressWithGestureLocationInBounds:gestureState:]_block_invoke ()

#5 0x00007fff48c2242e in _runAfterCACommitDeferredBlocks ()

#6 0x00007fff48c12bbc in _cleanUpAfterCAFlushAndRunDeferredBlocks ()

#7 0x00007fff48c43315 in _afterCACommitHandler ()

#8 0x00007fff23da1067 in __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ ()

#9 0x00007fff23d9bb1e in __CFRunLoopDoObservers ()

#10 0x00007fff23d9c06a in __CFRunLoopRun ()

#11 0x00007fff23d9b884 in CFRunLoopRunSpecific ()

#12 0x00007fff38b5ac1a in GSEventRunModal ()

#13 0x00007fff48c19220 in UIApplicationMain ()

#14 0x000000010d11dacb in main at /Users/dev/Projects/experimental/SwitchWarning/SwitchWarning/AppDelegate.swift:12

#15 0x00007fff519b910d in start ()

#16 0x00007fff519b910d in start ()

Who do you think is doing?

0

Answer 7

DTS Engineer OP

Apple

Apr ’20

Wow, that was depressingly easy to reproduce. I did a little digging and this is definitely a bug in UIKit, one that we’re tracking as (r. 57322394). The good news is that, AFAICT, it’s not actively toxic. CF is coping with this misbehaviour in a reasonable way.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

7

Answer 8

OOPer OP

Apr ’20

Thanks!

0

Answer 9

Daxa OP

May ’20

Hi Folks, I am getting the same issue and looks like UISwitch is broke. Is the fix for this comming soon ?

The issue happens when you toggle the switch even when it is not connected to any IBAction...

0

Answer 10

DTS Engineer OP

Apple

May ’20

Is the fix for this comming soon ?

I can’t talk about The Future™ [1].

Other than the log message, is this causing your any problems? If not, my advice is that you treat this as log noise.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

[1] My standard YouTube link for this has been taking down. I am most sad )-;

0

Answer 11

davidcc OP

Oct ’20

FWIW, this error is also occurring using a Toggle in SwiftUI. The toggle won't move!

0

Answer 12

AlexanderHH OP

Oct ’20

NB. RESOLVED below is now working

Have this same message in SwiftUI and the attached method isn't called. Is it something I'm doing wrong?

Code Block   Toggle(isOn: self.$isOn) {            EmptyView()  } .onChange(of: self.isOn) { _ in            print("**DEBUG - \(self.isOn)")   }

System:
Xcode 12.1 GM seed
6th Gen iPad mini - iPadOS 14.1

1

Answer 13

cgetcodes OP

Jun ’21

I am trying to write tests that involve a switch and am getting the popup "Timestamped Event Matching Error: Failed to find matching element".

Any ideas on how to proceed?

1

Answer 14

spiff OP

Jan ’22

It's January 2, 2022 and this still occurs.

2

Answer 15

loileebooztolentino OP

Jan ’22

Still happening.

2

	@IBAction func greetingFormat_Tapped(_ sender: UISwitch)
	{
	let theQuery = theTable_Settings.filter(settingID == 1)

	if sender.isOn
	{
	do {
	if try Database.shared.databaseConnection!.run(theQuery.update(greeting_Format <- "true")) > 0
	{
	greetingFormatLabel_Outlet.text = NSLocalizedString("HelloMrSmith_String", comment: "")
	} else {
	print("greeting format true not found")
	}
	} catch {
	print("greeting format true update failed! Error: \(error)")
	}
	} else {
	do {
	if try Database.shared.databaseConnection!.run(theQuery.update(greeting_Format <- "false")) > 0
	{
	greetingFormatLabel_Outlet.text = NSLocalizedString("HiJoe_String", comment: "")
	} else {
	print("greeting format false not found")
	}
	} catch {
	print("greeting format false update failed! Error: \(error)")
	}
	}
	}

	@IBAction func nonrefundableSwitch_Tapped(_ sender: UISwitch)
	{
	let theQuery = theTable_Settings.filter(settingID == 1)
	var itsOn: String = ""

	if sender.isOn
	{
	itsOn = "true"
	} else {
	itsOn = "false"
	}

	if itsOn == "true"
	{
	do {
	if try Database.shared.databaseConnection!.run(theQuery.update(nonRefundable_Bool <- "true")) > 0
	{
	depositDueLabel_Outlet.text = NSLocalizedString("nonRefunddepositisdue_String", comment: "")
	} else {
	print("nonRefundable true not found")
	}
	} catch {
	print("nonRefundable true update failed! Error: \(error)")
	}
	} else {
	do {
	if try Database.shared.databaseConnection!.run(theQuery.update(nonRefundable_Bool <- "false")) > 0
	{
	depositDueLabel_Outlet.text = NSLocalizedString("depositisdue_String", comment: "")
	} else {
	print("nonRefundable false not found")
	}
	} catch {
	print("nonRefundable false update failed! Error: \(error)")
	}
	}
	}