XCode 15.3, watchOS 10.4 SDK
Our health-related app is exploring adding an additional feature that would make use of extended runtime sessions to guide users through an activity. A user starts a session by tapping a button on the watchOS app's interface. If a session is already running, pressing that button should cause the current session to invalidate, and a new session should be created so we can start again from the beginning.
TLDR: Running new sessions works as expected on the simulator but not on a real device. Why?
We currently have a barebones implementation that includes logging in the extended runtime session delegate functions, on the button push, and when the new session is about to start.
Here's what our logging output for the simulator looks like when we try to invalidate the current session and run another one:
Invalidating extended session Optional("<WKExtendedRuntimeSession: 0x60000262d7a0> state=2, sessionID=4894EB1D-96F7-4921-8263-378E304E719F, expirationDate=2024-03-20 13:01:10 +0000") at 12:01:21 PM
Extended runtime session <WKExtendedRuntimeSession: 0x60000262d7a0> state=3, sessionID=4894EB1D-96F7-4921-8263-378E304E719F, expirationDate=2024-03-20 13:01:10 +0000 invalidated for reason WKExtendedRuntimeSessionInvalidationReason(rawValue: 0) with error nil at 12:01:21 PM
Requesting new extended session in application state 0 at 12:01:22 PM
Starting new extended session Optional("<WKExtendedRuntimeSession: 0x600002644540> state=0, sessionID=B34ECCFF-A0DA-45C1-9FD1-FD0F335FBE02, expirationDate=(null)") in application state 0 at 12:01:23 PM
Did start extended session <WKExtendedRuntimeSession: 0x600002644540> state=2, sessionID=B34ECCFF-A0DA-45C1-9FD1-FD0F335FBE02, expirationDate=2024-03-20 13:01:23 +0000 at 12:01:23 PM
As you can see, we successfully invalidate a running session, a button press requests a new one, and then we create and start a new runtime session instance which ends in the running (2) state. We can repeat this over and over without issue. The exact same code running on an actual device produces this:
Invalidating extended session Optional(\"<WKExtendedRuntimeSession: 0x15db5750> state=2, sessionID=889FE2E8-0FDA-4826-9094-4D48094FEBED, expirationDate=2024-03-20 12:53:55 +0000\") at 11:56:04AM
Extended runtime session <WKExtendedRuntimeSession: 0x15db5750> state=3, sessionID=889FE2E8-0FDA-4826-9094-4D48094FEBED, expirationDate=2024-03-20 12:53:55 +0000 invalidated for reason WKExtendedRuntimeSessionInvalidationReason(rawValue: 0) with error nil at 11:56:04AM
Requesting new extended session in application state 0 at 11:56:05AM
Starting new extended session Optional(\"<WKExtendedRuntimeSession: 0x15e0aba0> state=0, sessionID=D5020337-D20B-48BE-B2EE-EE44BE580AEC, expirationDate=(null)\") in application state 0 at 11:56:06AM
Extended runtime session <WKExtendedRuntimeSession: 0x15e0aba0> state=3, sessionID=D5020337-D20B-48BE-B2EE-EE44BE580AEC, expirationDate=(null) invalidated for reason WKExtendedRuntimeSessionInvalidationReason(rawValue: 1) with error nil at 11:56:06AM
The difference is in the last line: starting the session was unsuccessful and it was immediately invalidated, with the reason WKExtendedRuntimeSessionInvalidationReason(rawValue: 1) which maps to the enum sessionInProgress. This is surprising, since we just invalidated and dereferenced the old runtime session. What else can we do to tear down this session?
In fact, no other extended runtime sessions can be created and started successfully until the device is rebooted.
One note is that on the simulator we do get the following warning right after invalidating the running session:
-[WKExtendedRuntimeSession _invalidateWithError:]_block_invoke_2:527: Got error Error Domain=com.apple.CarouselServices.SessionErrorDomain Code=3 "Session not running <CSLSession: 0x600003b4eca0; pid: 8833; dismissed: NO; ended: YES; duration: 3600.0; autoEnd: NO; launchable: NO; mutuallyExclusive: YES; managed: YES; persisted: NO; requiresFGActiveInitiation: YES; lastForeground: 2024-03-20 12:01:21 +0000> |CSLSSession = {
| sessionID: 4894EB1D-96F7-4921-8263-378E304E719F; bundleID: com.bundle; type: "physical therapy"; running: NO; paused: NO; expirationDate: 2024-03-20 13:01:10 +0000; supportsAOT: NO; lastStartWasScheduled: NO; remote: NO;
|}" UserInfo={NSLocalizedDescription=Session not running <CSLSession: 0x600003b4eca0; pid: 8833; dismissed: NO; ended: YES; duration: 3600.0; autoEnd: NO; launchable: NO; mutuallyExclusive: YES; managed: YES; persisted: NO; requiresFGActiveInitiation: YES; lastForeground: 2024-03-20 12:01:21 +0000> |CSLSSession = {
| sessionID: 4894EB1D-96F7-4921-8263-378E304E719F; bundleID: com.bundle; type: "physical therapy"; running: NO; paused: NO; expirationDate: 2024-03-20 13:01:10 +0000; supportsAOT: NO; lastStartWasScheduled: NO; remote: NO;
|}}
This appears to be thrown by some part of Carousel, for which no public documentation exists, and it clearly doesn't disrupt the expected behavior on the simulator. I don't know if this is being thrown on the device, since our logging wouldn't be able to pick it up.
Please let me know if we are approaching this incorrectly or if there are any known solutions to this issue.
