Warning: That file was not part of the compilation database. It may have many parsing errors.

1/* Copyright (C) 1994-2019 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#include <hurd.h>
19#include <hurd/fd.h>
20#include <hurd/resource.h>
21#include <stdlib.h>
22#include "hurdmalloc.h" /* XXX */
23
24/* Allocate a new file descriptor and return it, locked. The new
25 descriptor number will be no less than FIRST_FD. If the table is full,
26 set errno to EMFILE and return NULL. If FIRST_FD is negative or bigger
27 than the size of the table, set errno to EINVAL and return NULL. */
28
29struct hurd_fd *
30_hurd_alloc_fd (int *fd, int first_fd)
31{
32 int i;
33 void *crit;
34 long int rlimit;
35
36 if (first_fd < 0)
37 {
38 errno = EINVAL;
39 return NULL;
40 }
41
42 crit = _hurd_critical_section_lock ();
43
44 __mutex_lock (&_hurd_dtable_lock);
45
46 search:
47 for (i = first_fd; i < _hurd_dtablesize; ++i)
48 {
49 struct hurd_fd *d = _hurd_dtable[i];
50 if (d == NULL)
51 {
52 /* Allocate a new descriptor structure for this slot,
53 initializing its port cells to nil. The test below will catch
54 and return this descriptor cell after locking it. */
55 d = _hurd_new_fd (MACH_PORT_NULL, MACH_PORT_NULL);
56 if (d == NULL)
57 {
58 __mutex_unlock (&_hurd_dtable_lock);
59 _hurd_critical_section_unlock (crit);
60 return NULL;
61 }
62 _hurd_dtable[i] = d;
63 }
64
65 __spin_lock (&d->port.lock);
66 if (d->port.port == MACH_PORT_NULL)
67 {
68 __mutex_unlock (&_hurd_dtable_lock);
69 _hurd_critical_section_unlock (crit);
70 if (fd != NULL)
71 *fd = i;
72 return d;
73 }
74 else
75 __spin_unlock (&d->port.lock);
76 }
77
78 __mutex_lock (&_hurd_rlimit_lock);
79 rlimit = _hurd_rlimits[RLIMIT_OFILE].rlim_cur;
80 __mutex_unlock (&_hurd_rlimit_lock);
81
82 if (first_fd < rlimit)
83 {
84 /* The descriptor table is full. Check if we have reached the
85 resource limit, or only the allocated size. */
86 if (_hurd_dtablesize < rlimit)
87 {
88 /* Enlarge the table. */
89 int save = errno;
90 struct hurd_fd **new;
91 /* Try to double the table size, but don't exceed the limit,
92 and make sure it exceeds FIRST_FD. */
93 int size = _hurd_dtablesize * 2;
94 if (size > rlimit)
95 size = rlimit;
96 else if (size <= first_fd)
97 size = first_fd + 1;
98
99 if (size * sizeof (*_hurd_dtable) < size)
100 {
101 /* Integer overflow! */
102 errno = ENOMEM;
103 goto out;
104 }
105
106 /* If we fail to allocate that, decrement the desired size
107 until we succeed in allocating it. */
108 do
109 new = realloc (_hurd_dtable, size * sizeof (*_hurd_dtable));
110 while (new == NULL && size-- > first_fd);
111
112 if (new != NULL)
113 {
114 /* We managed to allocate a new table. Now install it. */
115 errno = save;
116 if (first_fd < _hurd_dtablesize)
117 first_fd = _hurd_dtablesize;
118 /* Initialize the new slots. */
119 for (i = _hurd_dtablesize; i < size; ++i)
120 new[i] = NULL;
121 _hurd_dtablesize = size;
122 _hurd_dtable = new;
123 /* Go back to the loop to initialize the first new slot. */
124 goto search;
125 }
126 else
127 errno = ENOMEM;
128 }
129 else
130 errno = EMFILE;
131 }
132 else
133 errno = EINVAL; /* Bogus FIRST_FD value. */
134
135 out:
136 __mutex_unlock (&_hurd_dtable_lock);
137 _hurd_critical_section_unlock (crit);
138
139 return NULL;
140}
141

Warning: That file was not part of the compilation database. It may have many parsing errors.