glibc/nss/nss_files_data.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

162 lines
4.5 KiB
C

/* Returns a pointer to the global nss_files data structure.
Copyright (C) 2021-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <nss_files.h>
#include <allocate_once.h>
#include <errno.h>
#include <netdb.h>
#include <nss.h>
#include <stdlib.h>
/* This collects all per file-data. */
struct nss_files_data
{
struct nss_files_per_file_data files[nss_file_count];
};
/* For use with allocate_once. */
static void *nss_files_global;
static void *
nss_files_global_allocate (void *closure)
{
struct nss_files_data *result = malloc (sizeof (*result));
if (result != NULL)
{
for (int i = 0; i < nss_file_count; ++i)
{
result->files[i].stream = NULL;
__libc_lock_init (result->files[i].lock);
}
}
return result;
}
/* Like __nss_files_data_open, but does not perform the open call. */
static enum nss_status
__nss_files_data_get (struct nss_files_per_file_data **pdata,
enum nss_files_file file, int *errnop, int *herrnop)
{
struct nss_files_data *data = allocate_once (&nss_files_global,
nss_files_global_allocate,
NULL, NULL);
if (data == NULL)
{
if (errnop != NULL)
*errnop = errno;
if (herrnop != NULL)
{
__set_h_errno (NETDB_INTERNAL);
*herrnop = NETDB_INTERNAL;
}
return NSS_STATUS_TRYAGAIN;
}
*pdata = &data->files[file];
__libc_lock_lock ((*pdata)->lock);
return NSS_STATUS_SUCCESS;
}
/* Helper function for opening the backing file at PATH. */
static enum nss_status
__nss_files_data_internal_open (struct nss_files_per_file_data *data,
const char *path)
{
enum nss_status status = NSS_STATUS_SUCCESS;
if (data->stream == NULL)
{
data->stream = __nss_files_fopen (path);
if (data->stream == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
}
return status;
}
enum nss_status
__nss_files_data_open (struct nss_files_per_file_data **pdata,
enum nss_files_file file, const char *path,
int *errnop, int *herrnop)
{
enum nss_status status = __nss_files_data_get (pdata, file, errnop, herrnop);
if (status != NSS_STATUS_SUCCESS)
return status;
/* Be prepared that the set*ent function was not called before. */
if ((*pdata)->stream == NULL)
{
int saved_errno = errno;
status = __nss_files_data_internal_open (*pdata, path);
__set_errno (saved_errno);
if (status != NSS_STATUS_SUCCESS)
__nss_files_data_put (*pdata);
}
return status;
}
libc_hidden_def (__nss_files_data_open)
void
__nss_files_data_put (struct nss_files_per_file_data *data)
{
__libc_lock_unlock (data->lock);
}
libc_hidden_def (__nss_files_data_put)
enum nss_status
__nss_files_data_setent (enum nss_files_file file, const char *path)
{
struct nss_files_per_file_data *data;
enum nss_status status = __nss_files_data_get (&data, file, NULL, NULL);
if (status != NSS_STATUS_SUCCESS)
return status;
if (data->stream == NULL)
status = __nss_files_data_internal_open (data, path);
else
rewind (data->stream);
__nss_files_data_put (data);
return status;
}
libc_hidden_def (__nss_files_data_setent)
enum nss_status
__nss_files_data_endent (enum nss_files_file file)
{
/* No cleanup is necessary if not initialized. */
struct nss_files_data *data = atomic_load_acquire (&nss_files_global);
if (data == NULL)
return NSS_STATUS_SUCCESS;
struct nss_files_per_file_data *fdata = &data->files[file];
__libc_lock_lock (fdata->lock);
if (fdata->stream != NULL)
{
fclose (fdata->stream);
fdata->stream = NULL;
}
__libc_lock_unlock (fdata->lock);
return NSS_STATUS_SUCCESS;
}
libc_hidden_def (__nss_files_data_endent)