NetXMS Support Forum

Hi there,

I'm getting a segfault on server 4.3.3 (Debian) when using PushDCIData() in a transform script. If the DCI I'm pushing to has 'Save only changed values' enabled, then a segfault occurs.

I haven't been able to reproduce this behavior on a test platform, so can't rule out something else being the cause of the problem. Curiously, the fault only occurs after a restart of the server.

Thread 33 "$DATACOLL/WRK" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7ffff04b0700 (LWP 8118)]
DCItem::processNewValue (this=0x7ffe2f3a7410, tmTimeStamp=tmTimeStamp@entry=1680668319, originalValue=originalValue@entry=0x7ffc8bcad844 L"20", updateStatus=0x7ffff04a9b97) at dcitem.cpp:698
698    dcitem.cpp: No such file or directory.
(gdb) bt
#0  DCItem::processNewValue (this=0x7ffe2f3a7410, tmTimeStamp=tmTimeStamp@entry=1680668319, originalValue=originalValue@entry=0x7ffc8bcad844 L"20", updateStatus=0x7ffff04a9b97) at dcitem.cpp:698
#1  0x00007ffff7c18dee in DataCollectionTarget::processNewDCValue (this=this@entry=0x7ffe2ef49010, dcObject=std::shared_ptr<DCObject> (use count 2, weak count 0) = {...}, currTime=currTime@entry=1680668319,
    itemValue=0x7ffc8bcad844 L"20", tableValue=std::shared_ptr<Table> (empty) = {...}) at /usr/include/c++/8/bits/shared_ptr_base.h:1018
#2  0x00007ffff7beb450 in F_PushDCIData (argc=<optimized out>, argv=0x7ffc8bc15400, ppResult=0x7ffff04a9c50, vm=0x7ffc8bc42000) at /usr/include/c++/8/bits/shared_ptr_base.h:614
#3  0x00007ffff7a20547 in NXSL_VM::callExternalFunction (stackItems=3, function=<optimized out>, this=0x7ffc8bc42000) at ../../include/nxsl_classes.h:201
#4  NXSL_VM::callExternalFunction (this=0x7ffc8bc42000, function=<optimized out>, stackItems=3) at vm.cpp:2675
#5  0x00007ffff7a24ea7 in NXSL_VM::execute (this=0x7ffc8bc42000) at vm.cpp:1411
#6  0x00007ffff7a297c8 in NXSL_VM::run (this=this@entry=0x7ffc8bc42000, args=..., globals=globals@entry=0x0, expressionVariables=expressionVariables@entry=0x0, constants=constants@entry=0x0, entryPoint=entryPoint@entry=0x0)
    at vm.cpp:391
#7  0x00007ffff7a29c42 in NXSL_VM::run (this=this@entry=0x7ffc8bc42000, argc=argc@entry=1, argv=argv@entry=0x7ffff04aa040, globals=globals@entry=0x0, expressionVariables=expressionVariables@entry=0x0, constants=constants@entry=0x0,
    entryPoint=0x0) at vm.cpp:321
#8  0x00007ffff7c10dca in DCTable::transform (this=this@entry=0x7ffe2f140610, value=std::shared_ptr<Table> (use count 2, weak count 0) = {...}) at ../../../include/nxsl_classes.h:1427
#9  0x00007ffff7c116e9 in DCTable::processNewValue (this=0x7ffe2f140610, timestamp=timestamp@entry=1680668319, value=std::shared_ptr<Table> (use count 2, weak count 0) = {...}, updateStatus=updateStatus@entry=0x7ffff04aa527)
    at dctable.cpp:357
#10 0x00007ffff7c18d9c in DataCollectionTarget::processNewDCValue (this=0x7ffe2ef49010, dcObject=std::shared_ptr<DCObject> (use count 2, weak count 0) = {...}, currTime=currTime@entry=1680668319,
    itemValue=itemValue@entry=0x7ffff04aad60 L"", tableValue=std::shared_ptr<Table> (use count 2, weak count 0) = {...}) at /usr/include/c++/8/bits/shared_ptr_base.h:1018
#11 0x00007ffff7be49c8 in DataCollector (dcObject=std::shared_ptr<DCObject> (use count 2, weak count 0) = {...}) at /usr/include/c++/8/bits/shared_ptr_base.h:762
#12 0x00007ffff7c22afa in __ThreadPoolExecute_SharedPtr_Wrapper<DCObject> (arg=0x7ffc8c000020) at ../../../include/nms_threads.h:990
#13 0x00007ffff794c21e in ProcessSerializedRequests (data=0x7ffc8c00b050) at tp.cpp:487
#14 0x00007ffff794c066 in WorkerThread (threadInfo=0x7fffeb5b15b0) at tp.cpp:199
#15 0x00007ffff794de4a in ThreadCreate_Wrapper_1<WorkerThreadInfo*> (context=0x7fffeb5b15c0) at ../../include/nms_threads.h:536
#16 0x00007ffff779ffa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#17 0x00007ffff6ec206f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb)

Trying to do a transformation on a trap parameter. Have tried doing it this way:

oid = $1;
status = $2;
newStatus = "unknown";

switch (status)
{
   case "1"
      newStatus = "up";
      break;
   case "2":
      newStatus = "down";
      break;
}

return %(oid, newStatus);

It doesn't appear to work though, so how should I reference (and return) the parameter values?

Thanks.