doSMP: unable to create a task queue: limit exceeded

I am trying to use doSMP for parallel .CAll functions in windows R, but got the following errors:

1: In startWorkers(wr) : there is an existing doSMP session using doSMP1
2: In startWorkers(wr) : there is an existing doSMP session using doSMP2
3: In startWorkers(wr) : there is an existing doSMP session using doSMP3
4: In startWorkers(wr) : there is an existing doSMP session using doSMP4
5: In startWorkers(wr) : there is an existing doSMP session using doSMP5
6: In startWorkers(wr) : there is an existing doSMP session using doSMP6
7: In startWorkers(wr) : there is an existing doSMP session using doSMP7
8: In startWorkers(wr) : there is an existing doSMP session using doSMP8 
9: In startWorkers(wr) :
possible leak of worker sessions: c开发者_运维百科onsider using FORCE=TRUE

I did the rmSessions(all=TRUE), but R always freeze at the following lines:

attempting to delete qnames: doSMP1, doSMP2, doSMP3,doSMP4,doSMP5,doSMP6,doSMP7,doSMP8

I have restarted R and Windows many times, even tried to remove the package and reinstalled it but still not working. Is there anyway to remove these sessions?

What I want is to parallel the for loop which calls .Call, is there other packages can do this in windows R? Thanks a lot for your help.

I'm fairly new at using the doSMP library and have had the same problem as you. I'm sure there are other packages that do parallel processing, though doSMP seems to be fairly simple to use. I have developed the habit of putting the rmSessions(all=T) at the beginning of my code (after loading the doSMP library) just to make sure there are no sessions active and haven't had the problem of the program crashing. I think the thing you have to remember is to call the stopWorkers function every time your loop has finished otherwise R seems to get angry with you. Hope this helps.