1 Reply Latest reply on Feb 18, 2019 1:38 PM by Steven Si

    LinkOS IOS crashes

    Boris Yudasin

      Hey everyone,

       

      Having an issue with the official LinkOS SDK

       

      We're using LINK-OS-MULTIPLATFORM-SDK v1.5.1049 (https://www.zebra.com/us/en/support-downloads/printer-software/link-os-multiplatform-sdk.html)

      to print tickets on iMZ-320 printers from iOS devices (iOS 12.1.3) and we have a lot of crashes related to communication with printer, a stack trace looks like the following

       

       

      Crashed: com.apple.main-thread

      EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000420104400

      -[EAInputStream streamEventTrigger]

      Crashed: com.apple.main-thread

      0 libobjc.A.dylib 0x230990d7c objc_msgSend + 28

      1 ExternalAccessory 0x248672474 -[EAInputStream streamEventTrigger] + 324

      2 CoreFoundation 0x2317391f0 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 24

      3 CoreFoundation 0x231739170 CFRunLoopDoSource0 + 88

      4 CoreFoundation 0x231738aa8 CFRunLoopDoSources0 + 260

      5 CoreFoundation 0x231733920 __CFRunLoopRun + 1040

      6 CoreFoundation 0x2317331f0 CFRunLoopRunSpecific + 436

      7 GraphicsServices 0x2339ac584 GSEventRunModal + 100

      8 UIKitCore 0x25ea8ad40 UIApplicationMain + 212

      9 Agents Sightseeing.Tech 0x104acadd8 main (main.m:14)

      10 libdyld.dylib 0x2311f2bb4 start + 4

       

       

      Crashed: com.apple.main-thread

      EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000f7ed85410

      Crashed: com.apple.main-thread

      0 libobjc.A.dylib 0x18d38cd70 objc_msgSend + 16

      1 Agents Sightseeing.Tech 0x1051a156c -[MfiBtPrinterConnection write:error:] + 3037132

      2 Agents Sightseeing.Tech 0x1051989d8 +[SGD SET:withValue:andWithPrinterConnection:error:] + 3001400

      3 Agents Sightseeing.Tech 0x104bcf1fc -[ZebraConnection selectAccessory] (ZebraConnection.m:52)

       

       

      Crashed: com.apple.root.default-qos

      EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000001600000024

       

       

      Crashed: com.apple.root.default-qos

      0 libobjc.A.dylib 0x1f7c2cd7c objc_msgSend + 28

      1 ExternalAccessory 0x20f91e4e4 -[EAOutputStream close] + 140

      2 Agents Sightseeing.Tech 0x10070e238 -[Zebra_EADSessionController closeSession] + 3040408

      3 Agents Sightseeing.Tech 0x10070d37c -[MfiBtPrinterConnection close] + 3036636

      4 Agents Sightseeing.Tech 0x10013b2e8 __34-[ZebraConnection closeConnection]_block_invoke (ZebraConnection.m:61)

        • Re: LinkOS IOS crashes
          Steven Si

          There is not enough information to root cause this issue. When using Link-OS SDK for iOS, there are the recommended best practices. Among these best practices, two of them often get ignored.

          1. Always communicate to the printer on a thread other than the UI thread.
          2. Check the status of the printer before printing to ensure the printer is in a ready state-to-print.