EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  <20062007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  <20062007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
<== Date ==> <== Thread ==>

Subject: Deadlock when using asyn?
From: "Rees, NP \(Nick\)" <[email protected]>
To: "EPICS tech-talk" <[email protected]>
Date: Thu, 3 Aug 2006 17:58:51 +0100
Hi,

I have an asynSerial port that on VxWorks that is accessed by two tasks.
The first calls asynOctetSyncIO->writeRead in a private driver
background thread and the second access is in the asyn port thread using
asynRecord. The two tasks seem to deadlock over access to the two
semaphores: mutex pport->synchronousLock, and event
puserPvt->callbackDone.

Has anyone seen anything similar? What are the rules between mixing
asynOctetSyncIO and normal calls in the asynPort thread? I thought that
the lockPort in asynOctetSyncIO->writeRead was all that was needed.

Further information:

1. Asyn version: 4-6

2. Driver background thread stack trace:

#0  0x2276dc in semBTake ()
#1  0x2283ac in semTake ()
#2  0x1e74eb78 in cancelRequest (pasynUser=0x1ecf4168,
wasQueued=0x1ec9a18c) at ../../asyn/asynDriver/asynManager.c:1458
#3  0x1e72f0f8 in intrCallbackOctet (pasynUser=0x1ed179d8,
data=0x1ed4c130 "0\r", numchars=2) at ../AsynDriverInterface.cc:780
#4  0x1e75b3f0 in callInterruptUsers (pasynUser=0x1ed4c498,
pasynPvt=0x1ed4c5f0, data=0x1ed4c130 "0\r", nbytesTransfered=0x1ec9a294,
eomReason=0x1ec9a370) at ../../asyn/interfaces/asynOctetBase.c:218
#5  0x1e75b770 in readRaw (drvPvt=0x1ed4c7e0, pasynUser=0x1ed4c498,
data=0x1ed4c130 "0\r", maxchars=600, nbytesTransfered=0x1ec9a294,
eomReason=0x1ec9a370) at ../../asyn/interfaces/asynOctetBase.c:282
#6  0x1e762bec in readIt (ppvt=0x1ed4c580, pasynUser=0x1ed4c498,
data=0x1ed460ec "", maxchars=80, nbytesTransfered=0x1ec9a36c,
eomReason=0x1ec9a370) at ../../asyn/miscellaneous/asynInterposeEos.c:241
#7  0x1e75d300 in writeRead (pasynUser=0x1ed4c498,
write_buffer=0x1ed4609c "M161", write_buffer_len=4,
read_buffer=0x1ed460ec "", read_buffer_len=80, timeout=1,
nbytesOut=0x1ec9a368, nbytesIn=0x1ec9a36c, eomReason=0x1ec9a370) at
../../asyn/interfaces/asynOctetSyncIO.c:342
#8  0x1e6f4b84 in drvPmacMbxWriteRead (card=0, writebuf=0x1ed4609c
"M161", readbuf=0x1ed460ec "", errmsg=0x1ed4613c "") at
../drvPmac.c:1580
#9  0x1e6f52ec in drvPmacMbxTask (card=0) at ../drvPmac.c:1746
#10 0x231f7c in vxTaskEntry ()

3. Line 1458 in asynManager.c:
epicsEventMustWait(puserPvt->callbackDone);

4. Information on puserPvt->callbackDone:

ioc135 -> semShow 0x1ed113e0,5

Semaphore Id        : 0x1ed113e0
Semaphore Type      : BINARY
Task Queuing        : FIFO
Pended Tasks        : 1
State               : EMPTY
Options             : 0x0       SEM_Q_FIFO

VxWorks Events
--------------
Registered Task     : NONE
Event(s) to Send    : N/A
Options             : N/A

Pended Tasks
------------
   NAME      TID    PRI TIMEOUT
---------- -------- --- -------
pmacMbx0   1ec9a440  45       0

5. Stack trace for asynPort thread:

#0  0x229348 in semMTake ()
#1  0x2283ac in semTake ()
#2  0x1e8799ac in epicsMutexLock ()
#3  0x1e74b900 in portThread (pport=0x1ed4fcc0) at
../../asyn/asynDriver/asynManager.c:769
#4  0x1e882c68 in createFunction ()
#5  0x231f7c in vxTaskEntry ()

6. Line 769 in asynManager.c is:
epicsMutexMustLock(pport->synchronousLock);

7. Information on the pport->synchronousLock mutex is:

ioc135 -> epicsMutexShow 0x1ed4fbe0,5
epicsMutexId 0x1ed4fbe0 source ../../asyn/asynDriver/asynManager.c line
1714

Semaphore Id        : 0x1ed4fc10
Semaphore Type      : MUTEX
Task Queuing        : PRIORITY
Pended Tasks        : 1
Owner               : 0x1ec9a440   (pmacMbx0)
Options             : 0xd       SEM_Q_PRIORITY
                                SEM_DELETE_SAFE
                                SEM_INVERSION_SAFE

VxWorks Events
--------------
Registered Task     : NONE
Event(s) to Send    : N/A
Options             : N/A

Pended Tasks
------------
   NAME      TID    PRI TIMEOUT
---------- -------- --- -------
PMAC_ASC_0 1ed4f7b0 149       0


Any help would be greatefully received.

Cheers,

Nick Rees
Principal Software Engineer           Phone: +44 (0)1235-778430
Diamond Light Source                  Fax:   +44 (0)1235-446713


Replies:
Re: Deadlock when using asyn? Eric Norum

Navigate by Date:
Prev: RE: Problem building base 3.14.8.2 on Win32 Douglas Pearson
Next: Re: Deadlock when using asyn? Eric Norum
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  <20062007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
Navigate by Thread:
Prev: RE: Problem building base 3.14.8.2 on Win32 Douglas Pearson
Next: Re: Deadlock when using asyn? Eric Norum
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  <20062007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
ANJ, 02 Sep 2010 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·