source: mainline/uspace/libc/generic/io/vprintf.c@ 183788f1

/*
 * Copyright (c) 2006 Josef Cejka
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */

#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>
#include <io/printf_core.h>
#include <futex.h>
#include <async.h>

static atomic_t printf_futex = FUTEX_INITIALIZER;

static int vprintf_write(const char *str, size_t count, void *unused)
{
        return write(1, str, count);
}

/** Print formatted text.
 * @param fmt   format string
 * @param ap    format parameters
 * \see For more details about format string see printf_core.
 */
int vprintf(const char *fmt, va_list ap)
{
        struct printf_spec ps = {
                (int (*)(void *, size_t, void *)) vprintf_write,
                 NULL
        };
        /*
         * Prevent other threads to execute printf_core()
         */
        futex_down(&printf_futex);
        /*
         * Prevent other pseudo threads of the same thread
         * to execute printf_core()
         */
        async_serialize_start();
        int ret = printf_core(fmt, &ps, ap);
        async_serialize_end();
        futex_up(&printf_futex);
        return ret;
}

/** @}
 */