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1124 :: Question about the locks module

• GrahamStJack (orginal) [2015-04-13T02:26:07+02:00] view original

  The manual describes how to use guards and locks, but when I tried it out I found that guards are deprecated. They looked promising to me - can someone tell me what the future directions are in this area, or point me at the right place to read about it? Thanks.

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• Araq (orginal) [2015-04-13T15:56:58+02:00] view original

  Guards are not deprecated. Why do you think so?

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• GrahamStJack (orginal) [2015-04-13T23:20:13+02:00] view original

  That's good news.

  I thought so because I got deprecated error messages coming from the locks module that seemed to say so. I will start using them again, and post the error messages here.

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• GrahamStJack (orginal) [2015-04-14T01:05:01+02:00] view original

  Here is a code fragment that illustrates what I am trying to do:

  import tables, locks, osproc
  
  type
    Killer = object
      lock:                      TLock
      bailed    {.guard: lock.}: bool
      processes {.guard: lock.}: Table[int, Process]
  
  
  template hold(lock: TLock; body: stmt) =
    lock.acquire
    defer: lock.release
    {.locks: [lock].}:
      body
  
  
  # Initialize a Killer.
  proc initKiller(): Killer =
    initLock(result.lock)
    result.lock.hold:
      result.bailed = false
      result.processes = initTable[int, Process]()
  
  
  # remember that a process has been launched, killing it if we have bailed.
  proc launched(killer: var Killer, process: Process) =
    killer.lock.hold:
      if killer.bailed:
        process.terminate()
      else:
        killer.processes[process.processId] = process
  
  
  # A process has been finished with.
  proc completed(killer: var Killer, process: Process) =
    killer.lock.hold:
      killer.processes.del(process.processId)
  
  
  # Bail, doing nothing if already bailed.
  proc bail(killer: var Killer): bool =
    killer.lock.hold:
      result = not killer.bailed
      if not killer.bailed:
        killer.bailed = true
        for id, process in killer.processes:
          process.terminate
        killer.processes = initTable[int, Process]()
  
  
  # Global Killer instance.
  var killer = initKiller()
  Run

  When I compile this with default options, I get these warnings that I don't understand:

  lib/core/locks.nim(22, 43) Warning: LockEffect is deprecated [Deprecated] lib/core/locks.nim(25, 44) Warning: LockEffect is deprecated [Deprecated]

  Note that heaps of other deprecated warnings come out of the library modules, so I have to turn Deprecated and some other warnings off - but I would like to know what this one means.

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