Hi Heather,
On Tue, 2023-10-10 at 15:42 +0200, Mark Wielaard wrote:
> From: Heather McIntyre <h...@rice.edu>
>
> * lib/eu-search.h: New file.
> Declarations for read/write locked eu_tsearch/eu_tfind.
Like in the previous case, don't forget to add such a new header to
noinst_HEADERS so make dist adds them.
diff --git a/lib/Makefile.am b/lib/Makefile.am
index ce8f3e1b..9df0a8c6 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -39,5 +39,6 @@ libeu_a_SOURCES = xasprintf.c xstrdup.c xstrndup.c xmalloc.c
next_prime.c \
noinst_HEADERS = fixedsizehash.h libeu.h system.h dynamicsizehash.h list.h \
eu-config.h color.h printversion.h bpf.h \
- atomics.h stdatomic-fbsd.h dynamicsizehash_concurrent.h
+ atomics.h stdatomic-fbsd.h dynamicsizehash_concurrent.h \
+ eu-search.h
EXTRA_DIST = dynamicsizehash.c dynamicsizehash_concurrent.c
> * lib/eu-search.c: New file.
> Definitions for read/write locked eu_tsearch/eu_tfind.
> * Makefile.am (libeu_a_SOURCES): Add eu-search.c.
>
> Signed-off-by: Heather S. McIntyre <h...@rice.edu>
> Signed-off-by: Mark Wielaard <m...@klomp.org>
> ---
> lib/Makefile.am | 2 +-
> lib/eu-search.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++
> lib/eu-search.h | 39 ++++++++++++++++++++++++++++++++
> 3 files changed, 100 insertions(+), 1 deletion(-)
> create mode 100644 lib/eu-search.c
> create mode 100644 lib/eu-search.h
>
> diff --git a/lib/Makefile.am b/lib/Makefile.am
> index b3bb929f..ce8f3e1b 100644
> --- a/lib/Makefile.am
> +++ b/lib/Makefile.am
> @@ -34,7 +34,7 @@ AM_CPPFLAGS += -I$(srcdir)/../libelf
> noinst_LIBRARIES = libeu.a
>
> libeu_a_SOURCES = xasprintf.c xstrdup.c xstrndup.c xmalloc.c next_prime.c \
> - crc32.c crc32_file.c \
> + crc32.c crc32_file.c eu-search.c \
> color.c error.c printversion.c
OK.
> noinst_HEADERS = fixedsizehash.h libeu.h system.h dynamicsizehash.h list.h \
> diff --git a/lib/eu-search.c b/lib/eu-search.c
> new file mode 100644
> index 00000000..a6b04f4f
> --- /dev/null
> +++ b/lib/eu-search.c
> @@ -0,0 +1,60 @@
> +/* Definitions for thread-safe tsearch/tfind
> + Copyright (C) 2023 Rice University
> + This file is part of elfutils.
> +
> + This file is free software; you can redistribute it and/or modify
> + it under the terms of either
> +
> + * the GNU Lesser General Public License as published by the Free
> + Software Foundation; either version 3 of the License, or (at
> + your option) any later version
> +
> + or
> +
> + * 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
> +
> + or both in parallel, as here.
> +
> + elfutils 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 copies of the GNU General Public License and
> + the GNU Lesser General Public License along with this program. If
> + not, see <http://www.gnu.org/licenses/>. */
> +
> +#ifdef HAVE_CONFIG_H
> +#include <config.h>
> +#endif
> +
> +#include <stdlib.h>
> +#include "eu-search.h"
> +
> +rwlock_define(static, search_find_lock);
> +
> +void *eu_tsearch(const void *key, void **rootp,
> + int (*compar)(const void *, const void *))
> +{
> + void *ret = NULL;
> + rwlock_wrlock(search_find_lock);
> +
> + ret = tsearch(key, rootp, compar);
> +
> + rwlock_unlock(search_find_lock);
> + return ret;
> +}
> +
> +void *eu_tfind(const void *key, void *const *rootp,
> + int (*compar)(const void *, const void *))
> +{
> + void *ret = NULL;
> + rwlock_rdlock(search_find_lock);
> +
> + ret = tfind(key, rootp, compar);
> +
> + rwlock_unlock(search_find_lock);
> + return ret;
> +}
So this uses on static lock for all eu-tsearch/eu-tfind calls. But
searches with different roots should be independent. Would it make
sense to add different locks for different roots?
That would make the code a little more complicated, but we could hide
the root and lock in a new structure that will be passed the the
eu_tsearch/eu_tfind calls.
Maybe something like:
struct eu_search_root
{
void *root;
rwlock_define (,lock);
};
With helper functions to create/init and destroy/delete them?
void eu_tinit (struct eu_search_root *search_root);
(Or is there no real initing to do?)
void eu_tdestroy (struct eu_search_root *search_root,
void (*free_node)(void *nodep));
Or is all this way too complicated and a global lock just fine?
Cheers,
Mark
> diff --git a/lib/eu-search.h b/lib/eu-search.h
> new file mode 100644
> index 00000000..4ce0139a
> --- /dev/null
> +++ b/lib/eu-search.h
> @@ -0,0 +1,39 @@
> +/* Calls for thread-safe tsearch/tfind
> + Copyright (C) 2023 Rice University
> + This file is part of elfutils.
> +
> + This file is free software; you can redistribute it and/or modify
> + it under the terms of either
> +
> + * the GNU Lesser General Public License as published by the Free
> + Software Foundation; either version 3 of the License, or (at
> + your option) any later version
> +
> + or
> +
> + * 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
> +
> + or both in parallel, as here.
> +
> + elfutils 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 copies of the GNU General Public License and
> + the GNU Lesser General Public License along with this program. If
> + not, see <http://www.gnu.org/licenses/>. */
> +
> +#ifndef EU_SEARCH_H
> +#define EU_SEARCH_H 1
> +
> +#include <search.h>
> +
> +extern void *eu_tsearch(const void *key, void **rootp,
> + int (*compar)(const void *, const void *));
> +extern void *eu_tfind(const void *key, void *const *rootp,
> + int (*compar)(const void *, const void *));
> +
> +#endif
