1 /* Copyright (C) 1994 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If
16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
17 Cambridge, MA 02139, USA. */
21 #include <hurd/resource.h>
23 #include "hurdmalloc.h" /* XXX */
25 /* Allocate a new file descriptor and return it, locked. The new
26 descriptor number will be no less than FIRST_FD. If the table is full,
27 set errno to EMFILE and return NULL. If FIRST_FD is negative or bigger
28 than the size of the table, set errno to EINVAL and return NULL. */
31 _hurd_alloc_fd (int *fd, int first_fd)
43 crit = _hurd_critical_section_lock ();
45 __mutex_lock (&_hurd_dtable_lock);
48 for (i = first_fd; i < _hurd_dtablesize; ++i)
50 struct hurd_fd *d = _hurd_dtable[i];
53 /* Allocate a new descriptor structure for this slot,
54 initializing its port cells to nil. The test below will catch
55 and return this descriptor cell after locking it. */
56 d = _hurd_new_fd (MACH_PORT_NULL, MACH_PORT_NULL);
59 __mutex_unlock (&_hurd_dtable_lock);
60 _hurd_critical_section_unlock (crit);
66 __spin_lock (&d->port.lock);
67 if (d->port.port == MACH_PORT_NULL)
69 __mutex_unlock (&_hurd_dtable_lock);
70 _hurd_critical_section_unlock (crit);
76 __spin_unlock (&d->port.lock);
79 __mutex_lock (&_hurd_rlimit_lock);
80 rlimit = _hurd_rlimits[RLIMIT_OFILE].rlim_cur;
81 __mutex_unlock (&_hurd_rlimit_lock);
83 if (first_fd < rlimit)
85 /* The descriptor table is full. Check if we have reached the
86 resource limit, or only the allocated size. */
87 if (_hurd_dtablesize < rlimit)
89 /* Enlarge the table. */
92 /* Try to double the table size (but don't exceed the limit).
93 If there isn't any at all, give it three slots (because
94 stdio will take that many anyway). */
95 int size = _hurd_dtablesize ? _hurd_dtablesize * 2 : 3;
98 /* If we fail to allocate that, decrement the desired size
99 until we succeed in allocating it. */
101 new = realloc (_hurd_dtable, size * sizeof (*_hurd_dtable));
102 while (new == NULL && size-- > _hurd_dtablesize);
105 /* We managed to allocate a new table. Now install it. */
107 first_fd = _hurd_dtablesize;
108 /* Initialize the new slots. */
109 for (i = first_fd; i < size; ++i)
111 _hurd_dtablesize = size;
113 /* Go back to the loop to initialize the first new slot. */
121 errno = EINVAL; /* Bogus FIRST_FD value. */
123 __mutex_unlock (&_hurd_dtable_lock);
124 _hurd_critical_section_unlock (crit);