[vlc-devel] [PATCH v2] compat: add qsort_r()

[Rémi Denis-Courmont]

Le tiistaina 20. marraskuuta 2018, 16.36.41 EET Romain Vimont a écrit :
> Add qsort_r() based on qsort() with Thread Local Storage to store the
> comparison context.
> ---
>  compat/qsort_r.c     | 47 ++++++++++++++++++++++++++++++++++++++++++++
>  configure.ac         |  2 +-
>  include/vlc_fixups.h |  7 +++++++
>  3 files changed, 55 insertions(+), 1 deletion(-)
>  create mode 100644 compat/qsort_r.c
> 
> diff --git a/compat/qsort_r.c b/compat/qsort_r.c
> new file mode 100644
> index 0000000000..9519ddafc6
> --- /dev/null
> +++ b/compat/qsort_r.c
> @@ -0,0 +1,47 @@
> +/**
> + * @file qsort_r.c
> + * @brief replacement for GNU qsort_r()
> + */
> +/**************************************************************************
> *** + * Copyright (C) 2018 VLC authors and VideoLAN
> + *
> + * This program 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.
> + *
> + * 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 Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public License
> + * along with this program; if not, write to the Free Software Foundation,
> + * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. +
> ***************************************************************************
> **/ +
> +#ifdef HAVE_CONFIG_H
> +# include "config.h"
> +#endif
> +
> +#include <stdlib.h>
> +
> +static thread_local struct qsort_r_context
> +{
> +    int (*compar)(const void *, const void *, void *);
> +    void *arg;
> +} qsort_r_ctx;
> +
> +static int qsort_cmp(const void *lhs, const void *rhs)
> +{
> +    return qsort_r_ctx.compar(lhs, rhs, qsort_r_ctx.arg);
> +}
> +
> +void qsort_r(void *base, size_t nmemb, size_t size,
> +             int (*compar)(const void *, const void *, void *),
> +             void *arg)
> +{
> +    qsort_r_ctx.compar = compar;
> +    qsort_r_ctx.arg = arg;
> +    qsort(base, nmemb, size, qsort_cmp);
> +}

The final r in qsort_r () stands for reentrant, and that there is not 
reentrant.

-- 
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