include/wvlockfile.h

   1 /* -*- Mode: C++ -*-
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * A simple lockfile class using WvStreams.
   6  */
   7
   8 #ifndef __WVLOCKFILE_H
   9 #define __WVLOCKFILE_H
  10
  11 #include "wvfile.h"
  12
  13
  14 class WvLockFile
  15 {
  16 public:
  17     WvLockFile(WvStringParm _lockname);
  18
  19     /** Check to make sure no lock is established or that it's owned by us. */
  20     bool isok();
  21
  22     /** Creates the lockfile with the current pid. Returns success/failure. */
  23     bool lock();
  24
  25     /**
  26      * Removes the lockfile if present. If there's no lockfile after,
  27      * returns true, otherwise false.
  28      */
  29     bool unlock();
  30
  31     /**
  32      * Returns one of three things:
  33      *   -1 if the lockfile exists, but is inaccessible.
  34      *   0  if there is no lockfile, or the process is not running.
  35      *   >0 The pid of the known-running process that owns the lock.
  36      */
  37     pid_t readpid();
  38
  39 protected:
  40     WvString lockname;
  41 };
  42
  43 #endif // __WVLOCKFILE_H