Experimental Physics and
Industrial Control System

[email protected] (Ralph Lange) · Mon, 16 Jun 1997 11:22:47 +0200 (METDST)

Oops - here we go again.

Now it hit another IOC - No special hardware on that one, just the CAN
fieldbus support that has been running on all our IOCs from the beginning.
The only thing that just the two faulty IOCs have in common and the only
thing quite new on them is that the sequencer is loaded and there are seq
state machines running.

-> i

  NAME        ENTRY       TID    PRI   STATUS      PC       SP     ERRNO  DELAY
---------- ------------ -------- --- ---------- -------- -------- ------- -----

...
scanOnce   6fba0e         520a70  65 SUSPEND      6ec252   520a28       0     0

-> checkStack
  NAME        ENTRY        TID     SIZE   CUR  HIGH  MARGIN
------------ ------------ -------- ----- ----- ----- ------

...
scanOnce     0x00006fba0e 520a70    9664    72  1076   8588 

-> tt "scanOnce"
 79c3c _vxTaskEntry   +10 : 6fba0e (0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
6fba92 _scanOnce      +13e: _dbScanLock (c40064dd)
value = 0 = 0x0

-> l
6fba76  487a ff69                PEA         (0xff69,PC)
6fba7a  4878 01c9                PEA         0x000001c9
6fba7e  487a fd7f                PEA         (0xfd7f,PC)
6fba82  42a7                     CLR   .L    -(A7)
6fba84  61ff 0001 6e64           BSR         _errPrintf
6fba8a  504f                     ADDQ  .W    #0x8,A7
6fba8c  504f                     ADDQ  .W    #0x8,A7
6fba8e  2f2e fffc                MOVE  .L    (0xfffc,A6),-(A7)
6fba92  61ff ffff 07b2           BSR         _dbScanLock
6fba98  2eae fffc                MOVE  .L    (0xfffc,A6),(A7)
value = 7322268 = 0x6fba9c = _scanOnce + 0x148
-> l
6fba9c  61ff ffff 1890           BSR         _dbProcess
6fbaa2  2eae fffc                MOVE  .L    (0xfffc,A6),(A7)
6fbaa6  61ff ffff 0860           BSR         _dbScanUnlock
6fbaac  584f                     ADDQ  .W    #0x4,A7
6fbaae  6094                     BRA         0x006fba44
6fbab0  4e71                     NOP         
                        _scanOnceSetQueueSize:
6fbab2  4e56 0000                LINK  .W    A6,#0
6fbab6  23ee 0008 0072 9188      MOVE  .L    (0x8,A6),_onceQueueSize
6fbabe  4280                     CLR   .L    D0
6fbac0  4e5e                     UNLK        A6
value = 7322306 = 0x6fbac2 = _scanOnceSetQueueSize + 0x10

Am I interpreting this right thinking that the reason for the scanOnce
task's crash is its dbScanLock call (first level call caused by a CA wakeup
to the scanOnce task as opposed to subsequent calls from faulty support of
other records in the line of forward linked processing)? I.e. the task
reads junk from the ring buffer? The ring buffer that officially only CA
writes into?

Even more clueless, (I didn't think this to be increasable...)
Ralph

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System