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10124 :: Nim Threading question

• WipWapWoop (orginal) [2023-04-22T20:45:04+02:00] view original

  Hi,

  So basically in simple, the code below is the code with an error:

  import std/locks
  import system/threads
  
  var
    thr: array[2, Thread[string]]
    L: Lock
  
  proc SendString(msg: string): void =
    L.acquire()
    echo msg
    L.release()
  
  initLock(L)
  for i in 0..len(thr):
    if(i == 1): thr[i].createThread(SendString, "hello")
    else: thr[i].createThread(SendString, "Goodbye")
  
  joinThreads(thr)
  deinitLock(L)
  Run

  But I really do not get it. What I've done wrong? From what I read in the docs, it has to work right...

  # api ref
  proc createThread*[TArg](t: var Thread[TArg];
                           tp: proc (arg: TArg) {.thread, nimcall.}; param: TArg)
  Run

  the err i get:

  
  template/generic instantiation of `createThread` from here
  
  discard
  allocShared0Impl(sizeof(GcThread)))' has no type (or is ambiguous)
  Run

---

• noah (orginal) [2023-04-22T23:52:20+02:00] view original

  this executes for me

  • you dont need to import system/threads (or anything from system
  • and you need to compile with --threads:on

  import std/locks
  
  var
    thr: array[2, Thread[string]]
    L: Lock
  
  proc sendString(msg: string): void =
    L.acquire()
    echo msg
    L.release()
  
  initLock(L)
  for i in thr.low .. thr.high:
    if(i == 1): thr[i].createThread(sendString, "hello")
    else: thr[i].createThread(sendString, "Goodbye")
  
  joinThreads(thr)
  deinitLock(L)
  Run

---