regcomp.c: do not ignore memory allocation failure
[glibc.git] / hurd / alloc-fd.c
blob58eea52917a87282b52afba04e4ebe6322f8fa15
1 /* Copyright (C) 1994, 1995, 1996, 1997 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 Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the 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 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
19 #include <hurd.h>
20 #include <hurd/fd.h>
21 #include <hurd/resource.h>
22 #include <stdlib.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. */
30 struct hurd_fd *
31 _hurd_alloc_fd (int *fd, int first_fd)
33 int i;
34 void *crit;
35 long int rlimit;
37 if (first_fd < 0)
39 errno = EINVAL;
40 return NULL;
43 crit = _hurd_critical_section_lock ();
45 __mutex_lock (&_hurd_dtable_lock);
47 search:
48 for (i = first_fd; i < _hurd_dtablesize; ++i)
50 struct hurd_fd *d = _hurd_dtable[i];
51 if (d == NULL)
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);
57 if (d == NULL)
59 __mutex_unlock (&_hurd_dtable_lock);
60 _hurd_critical_section_unlock (crit);
61 return NULL;
63 _hurd_dtable[i] = d;
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);
71 if (fd != NULL)
72 *fd = i;
73 return d;
75 else
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. */
90 int save = errno;
91 struct hurd_fd **new;
92 /* Try to double the table size, but don't exceed the limit,
93 and make sure it exceeds FIRST_FD. */
94 int size = _hurd_dtablesize * 2;
95 if (size > rlimit)
96 size = rlimit;
97 else if (size <= first_fd)
98 size = first_fd + 1;
100 if (size * sizeof (*_hurd_dtable) < size)
102 /* Integer overflow! */
103 errno = ENOMEM;
104 goto out;
107 /* If we fail to allocate that, decrement the desired size
108 until we succeed in allocating it. */
110 new = realloc (_hurd_dtable, size * sizeof (*_hurd_dtable));
111 while (new == NULL && size-- > first_fd);
113 if (new != NULL)
115 /* We managed to allocate a new table. Now install it. */
116 errno = save;
117 if (first_fd < _hurd_dtablesize)
118 first_fd = _hurd_dtablesize;
119 /* Initialize the new slots. */
120 for (i = _hurd_dtablesize; i < size; ++i)
121 new[i] = NULL;
122 _hurd_dtablesize = size;
123 _hurd_dtable = new;
124 /* Go back to the loop to initialize the first new slot. */
125 goto search;
127 else
128 errno = ENOMEM;
130 else
131 errno = EMFILE;
133 else
134 errno = EINVAL; /* Bogus FIRST_FD value. */
136 out:
137 __mutex_unlock (&_hurd_dtable_lock);
138 _hurd_critical_section_unlock (crit);
140 return NULL;