glibc/string/strsignal.c

126 lines
3.1 KiB
C

/* Copyright (C) 1991-2015 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
<http://www.gnu.org/licenses/>. */
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libintl.h>
#include <bits/libc-lock.h>
static __libc_key_t key;
/* If nonzero the key allocation failed and we should better use a
static buffer than fail. */
#define BUFFERSIZ 100
static char local_buf[BUFFERSIZ];
static char *static_buf;
/* Destructor for the thread-specific data. */
static void init (void);
static void free_key_mem (void *mem);
static char *getbuffer (void);
/* Return a string describing the meaning of the signal number SIGNUM. */
char *
strsignal (int signum)
{
__libc_once_define (static, once);
const char *desc;
/* If we have not yet initialized the buffer do it now. */
__libc_once (once, init);
if (
#ifdef SIGRTMIN
(signum >= SIGRTMIN && signum <= SIGRTMAX) ||
#endif
signum < 0 || signum >= NSIG
|| (desc = _sys_siglist[signum]) == NULL)
{
char *buffer = getbuffer ();
int len;
#ifdef SIGRTMIN
if (signum >= SIGRTMIN && signum <= SIGRTMAX)
len = __snprintf (buffer, BUFFERSIZ - 1, _("Real-time signal %d"),
signum - SIGRTMIN);
else
#endif
len = __snprintf (buffer, BUFFERSIZ - 1, _("Unknown signal %d"),
signum);
if (len >= BUFFERSIZ)
buffer = NULL;
else
buffer[len] = '\0';
return buffer;
}
return (char *) _(desc);
}
/* Initialize buffer. */
static void
init (void)
{
if (__libc_key_create (&key, free_key_mem))
/* Creating the key failed. This means something really went
wrong. In any case use a static buffer which is better than
nothing. */
static_buf = local_buf;
}
/* Free the thread specific data, this is done if a thread terminates. */
static void
free_key_mem (void *mem)
{
free (mem);
__libc_setspecific (key, NULL);
}
/* Return the buffer to be used. */
static char *
getbuffer (void)
{
char *result;
if (static_buf != NULL)
result = static_buf;
else
{
/* We don't use the static buffer and so we have a key. Use it
to get the thread-specific buffer. */
result = __libc_getspecific (key);
if (result == NULL)
{
/* No buffer allocated so far. */
result = malloc (BUFFERSIZ);
if (result == NULL)
/* No more memory available. We use the static buffer. */
result = local_buf;
else
__libc_setspecific (key, result);
}
}
return result;
}