sortix-mirror/libc/stdio/fresetfile.c

45 lines
1.7 KiB
C

/*
* Copyright (c) 2011, 2012, 2013, 2014 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* stdio/fresetfile.c
* After a FILE has been shut down, returns all fields to their default state.
*/
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Note: This function preserves a few parts of the fields - this means that if
// you are using this to reset a fresh FILE object, you should memset it
// to zeroes first to avoid problems.
void fresetfile(FILE* fp)
{
FILE* prev = fp->prev;
FILE* next = fp->next;
unsigned char* keep_buffer = fp->buffer;
void* free_user = fp->free_user;
void (*free_func)(void*, FILE*) = fp->free_func;
int kept_flags = fp->flags & (_FILE_REGISTERED | 0);
memset(fp, 0, sizeof(*fp));
fp->buffer = keep_buffer;
fp->file_lock = (pthread_mutex_t) PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
fp->flags = kept_flags;
fp->buffer_mode = -1;
fp->free_user = free_user;
fp->free_func = free_func;
fp->prev = prev;
fp->next = next;
}