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