lumiera_/src/lib/error.c
2008-04-08 23:27:21 +01:00

82 lines
2.3 KiB
C

/*
error.c - Lumiera Error handling
Copyright (C) Lumiera.org
2008, Christian Thaeter <ct@pipapo.org>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <pthread.h>
#include "lib/error.h"
/**
* @file C Error handling in Lumiera.
*/
/*
predefined errors
*/
LUMIERA_ERROR_DEFINE (ERRNO, "errno");
/* Thread local storage */
static pthread_key_t lumiera_error_tls;
static pthread_once_t lumiera_error_initialized = PTHREAD_ONCE_INIT;
static void
lumiera_error_tls_init (void)
{
pthread_key_create (&lumiera_error_tls, NULL);
}
/**
* Set error state for the current thread.
* If the error state of the current thread was cleared, then set it, else preserve the old state.
* @param nerr name of the error with 'LUMIERA_ERROR_' prefix (example: LUMIERA_ERROR_NO_MEMORY)
* @return old state, that is NULL for success, when the state was cleared and a pointer to a pending
* error when the error state was already set
*/
const char*
lumiera_error_set (const char * nerr)
{
pthread_once (&lumiera_error_initialized, lumiera_error_tls_init);
const char* err = pthread_getspecific (lumiera_error_tls);
if (!err)
pthread_setspecific (lumiera_error_tls, nerr);
return err;
}
/**
* Get and clear current error state.
* This function clears the error state, if it needs to be reused, one has to store it in a temporary
* variable.
* @return pointer to any pending error of this thread, NULL if no error is pending
*/
const char*
lumiera_error ()
{
pthread_once (&lumiera_error_initialized, lumiera_error_tls_init);
const char* err = pthread_getspecific (lumiera_error_tls);
if (err)
pthread_setspecific (lumiera_error_tls, NULL);
return err;
}