imap/src/osdep/unix/flockcyg.h

   1 /* ========================================================================
   2  * Copyright 1988-2006 University of Washington
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  *
  11  * ========================================================================
  12  */
  13
  14 /*
  15  * Program:     flock() emulation via fcntl() locking
  16  *
  17  * Author:      Mark Crispin
  18  *              Networks and Distributed Computing
  19  *              Computing & Communications
  20  *              University of Washington
  21  *              Administration Building, AG-44
  22  *              Seattle, WA  98195
  23  *              Internet: MRC@CAC.Washington.EDU
  24  *
  25  * Date:        10 April 2001
  26  * Last Edited: 30 August 2006
  27  */
  28
  29 /* Cygwin does not seem to have the design flaw in fcntl() locking that
  30  * most other systems do (see flocksim.c for details).  If some cretin
  31  * decides to implement that design flaw, then Cygwin will have to use
  32  * flocksim.  Also, we don't test NFS either
  33  */
  34
  35
  36 #define flock flocksim          /* use ours instead of theirs */
  37
  38 #undef LOCK_SH
  39 #define LOCK_SH 1               /* shared lock */
  40 #undef LOCK_EX
  41 #define LOCK_EX 2               /* exclusive lock */
  42 #undef LOCK_NB
  43 #define LOCK_NB 4               /* no blocking */
  44 #undef LOCK_UN
  45 #define LOCK_UN 8               /* unlock */
  46
  47
  48 /* Function prototypes */
  49
  50 int flocksim (int fd,int operation);