Haskell get set thread name -

when print in java, append name of thread print statement know thread running print statement. how , set thread name in haskell? if can't set thread name, how make thread has given name?

note: give threads descriptive names "gui_thread", "main_thread", "database_thread", etc

as said in comment can use labelthread give thread label. sadly not find way pull label out (all found invalid ticket wanted this).

but descriped in parallel , concurrent programming in haskell can event-log view on this:

(straight there – hope nobody minds):

main =   t <- mythreadid   labelthread t "main"   m <- newemptymvar   t <- forkio $ putmvar m 'a'   labelthread t "a"   t <- forkio $ putmvar m 'b'   labelthread t "b"   traceeventio "before takemvar"   takemvar m   takemvar m 

you should compile threaded , eventlog switches set:

ghc mvar4.hs -threaded -eventlog 

and can call +rts , -l:

./mvar4 +rts -l 

finally can @ output ghc-evetns:

ghc-events show mvar4.eventlog 

---

naive self-implementation

that seems not want, here (very basic) example of how (using lists , mvar keep association between threadid , name):

import control.concurrent  type labels = mvar [(threadid, string)]  initlabels :: io labels initlabels = newmvar []  labelthread :: labels -> threadid -> string -> io () labelthread labels threadid label =   modifymvar_ labels (\assocs -> return $ (threadid, label):assocs)  getlabel :: labels -> threadid -> io string getlabel labels threadid = withmvar labels (\assocs ->   case lookup threadid assocs of     label -> return label     nothing    -> return $ show threadid) 

and can use this:

main :: io () main =   ls <- initlabels   myid <- mythreadid   getlabel ls myid >>= print   labelthread ls myid "my thread"   getlabel ls myid >>= print 

which you:

λ> :main "threadid 50" "my thread" 

obviously might not idea if create lots of threads. @ least should add remove label again @ end of thread:

removelabel :: labels -> threadid -> io () removelabel labels threadid =   modifymvar_ labels (return . filter ((/= threadid) . fst))  forklabeledio :: labels -> string -> io () -> io threadid forklabeledio labels label computation = forkio $   myid <- mythreadid   labelthread labels myid label   computation   removelabel labels myid 

... yeah know: nasty – , of course map might better idea – hope basic idea