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/**************************************************************************/
/* */
/* OCaml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. */
/* */
/* All rights reserved. This file is distributed under the terms of */
/* the GNU Lesser General Public License version 2.1, with the */
/* special exception on linking described in the file LICENSE. */
/* */
/**************************************************************************/
#include <errno.h>
#include <fcntl.h>
#include <caml/fail.h>
#include <caml/mlvalues.h>
#include <caml/signals.h>
#include "unixsupport.h"
#if defined(F_GETLK) && defined(F_SETLK) && defined(F_SETLKW)
CAMLprim value caml_unix_lockf(value fd, value cmd, value span)
{
struct flock l;
int ret;
int fildes;
long size;
fildes = Int_val(fd);
size = Long_val(span);
l.l_whence = 1;
if (size < 0) {
l.l_start = size;
l.l_len = -size;
} else {
l.l_start = 0L;
l.l_len = size;
}
switch (Int_val(cmd)) {
case 0: /* F_ULOCK */
l.l_type = F_UNLCK;
ret = fcntl(fildes, F_SETLK, &l);
break;
case 1: /* F_LOCK */
l.l_type = F_WRLCK;
caml_enter_blocking_section();
ret = fcntl(fildes, F_SETLKW, &l);
caml_leave_blocking_section();
break;
case 2: /* F_TLOCK */
l.l_type = F_WRLCK;
ret = fcntl(fildes, F_SETLK, &l);
break;
case 3: /* F_TEST */
l.l_type = F_WRLCK;
ret = fcntl(fildes, F_GETLK, &l);
if (ret != -1) {
if (l.l_type == F_UNLCK)
ret = 0;
else {
errno = EACCES;
ret = -1;
}
}
break;
case 4: /* F_RLOCK */
l.l_type = F_RDLCK;
caml_enter_blocking_section();
ret = fcntl(fildes, F_SETLKW, &l);
caml_leave_blocking_section();
break;
case 5: /* F_TRLOCK */
l.l_type = F_RDLCK;
ret = fcntl(fildes, F_SETLK, &l);
break;
default:
errno = EINVAL;
ret = -1;
}
if (ret == -1) caml_uerror("lockf", Nothing);
return Val_unit;
}
#else
#ifdef HAS_LOCKF
#ifdef HAS_UNISTD
#include <unistd.h>
#else
#define F_ULOCK 0
#define F_LOCK 1
#define F_TLOCK 2
#define F_TEST 3
#endif
static const int lock_command_table[] = {
F_ULOCK, F_LOCK, F_TLOCK, F_TEST, F_LOCK, F_TLOCK
};
CAMLprim value caml_unix_lockf(value fd, value cmd, value span)
{
if (lockf(Int_val(fd), lock_command_table[Int_val(cmd)], Long_val(span))
== -1) caml_uerror("lockf", Nothing);
return Val_unit;
}
#else
CAMLprim value caml_unix_lockf(value fd, value cmd, value span)
{ caml_invalid_argument("lockf not implemented"); }
#endif
#endif
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