contrib/python_1.5.2-fcntl_lockf.diff

   1 --- python-1.5.2/Modules/fcntlmodule.c.orig     Wed Jan  6 13:44:23 1999
   2 +++ python-1.5.2/Modules/fcntlmodule.c  Sun Apr  1 07:42:54 2001
   3 @@ -233,30 +233,12 @@
   4  {
   5         int fd, code, ret, whence = 0;
   6         PyObject *lenobj = NULL, *startobj = NULL;
   7 +       struct flock l;
   8
   9         if (!PyArg_ParseTuple(args, "ii|OOi", &fd, &code,
  10                               &lenobj, &startobj, &whence))
  11             return NULL;
  12
  13 -#ifndef LOCK_SH
  14 -#define LOCK_SH                1       /* shared lock */
  15 -#define LOCK_EX                2       /* exclusive lock */
  16 -#define LOCK_NB                4       /* don't block when locking */
  17 -#define LOCK_UN                8       /* unlock */
  18 -#endif
  19 -       {
  20 -               struct flock l;
  21 -               if (code == LOCK_UN)
  22 -                       l.l_type = F_UNLCK;
  23 -               else if (code & LOCK_SH)
  24 -                       l.l_type = F_RDLCK;
  25 -               else if (code & LOCK_EX)
  26 -                       l.l_type = F_WRLCK;
  27 -               else {
  28 -                       PyErr_SetString(PyExc_ValueError,
  29 -                                       "unrecognized flock argument");
  30 -                       return NULL;
  31 -               }
  32                 l.l_start = l.l_len = 0;
  33                 if (startobj != NULL) {
  34  #if !defined(HAVE_LARGEFILE_SUPPORT)
  35 @@ -281,10 +263,45 @@
  36                                 return NULL;
  37                 }
  38                 l.l_whence = whence;
  39 +       switch (code)
  40 +         {
  41 +         case F_TEST:
  42 +           /* Test the lock: return 0 if FD is unlocked or locked by this process;
  43 +              return -1, set errno to EACCES, if another process holds the lock.  */
  44 +           if (fcntl (fd, F_GETLK, &l) < 0) {
  45 +             PyErr_SetFromErrno(PyExc_IOError);
  46 +             return NULL;
  47 +           }
  48 +           if (l.l_type == F_UNLCK || l.l_pid == getpid ()) {
  49 +             Py_INCREF(Py_None);
  50 +             return Py_None;
  51 +           }
  52 +           errno = EACCES;
  53 +           PyErr_SetFromErrno(PyExc_IOError);
  54 +           return NULL;
  55 +
  56 +         case F_ULOCK:
  57 +           l.l_type = F_UNLCK;
  58 +           code = F_SETLK;
  59 +           break;
  60 +         case F_LOCK:
  61 +           l.l_type = F_WRLCK;
  62 +           code = F_SETLKW;
  63 +           break;
  64 +         case F_TLOCK:
  65 +           l.l_type = F_WRLCK;
  66 +           code = F_SETLK;
  67 +           break;
  68 +
  69 +         default:
  70 +           PyErr_SetString(PyExc_ValueError,
  71 +                           "unrecognized flock argument");
  72 +           return NULL;
  73 +         }
  74                 Py_BEGIN_ALLOW_THREADS
  75 -               ret = fcntl(fd, (code & LOCK_NB) ? F_SETLK : F_SETLKW, &l);
  76 +         ret = fcntl(fd, code, &l);
  77                 Py_END_ALLOW_THREADS
  78 -       }
  79 +
  80         if (ret < 0) {
  81                 PyErr_SetFromErrno(PyExc_IOError);
  82                 return NULL;