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From: "Carlo Marcelo Arenas Belón via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: "Carlo Marcelo Arenas Belón" <carenas@gmail.com>,
	"Johannes Schindelin" <johannes.schindelin@gmx.de>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Carlo Marcelo Arenas Belón" <carenas@gmail.com>
Subject: [PATCH 1/3] grep: make PCRE1 aware of custom allocator
Date: Wed, 16 Oct 2019 12:06:51 +0000	[thread overview]
Message-ID: <4feb8cc83a6d0b73bd7e47a513b91ce193c6ed6f.1571227613.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.402.git.1571227613.gitgitgadget@gmail.com>

From: =?UTF-8?q?Carlo=20Marcelo=20Arenas=20Bel=C3=B3n?= <carenas@gmail.com>

63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09) didn't include a way
to override the system alocator, and so it is incompatible with
USE_NED_ALLOCATOR as reported by Dscho[1] (in similar code from PCRE2)

Note that nedmalloc, as well as other custom allocators like jemalloc
and mi-malloc, can be configured at runtime (via `LD_PRELOAD`),
therefore we cannot know at compile time whether a custom allocator is
used or not.

Make the minimum change possible to ensure this combination is supported
by extending `grep_init()` to set the PCRE1 specific functions to Git's
idea of `malloc()` and `free()` and therefore making sure all
allocations are done inside PCRE1 with the same allocator than the rest
of Git.

This change has negligible performance impact: PCRE needs to allocate
memory once per program run for the character table and for each pattern
compilation. These are both rare events compared to matching patterns
against lines. Actual measurements[2] show that the impact is lost in
the noise.

[1] https://public-inbox.org/git/pull.306.git.gitgitgadget@gmail.com
[2] https://public-inbox.org/git/7f42007f-911b-c570-17f6-1c6af0429586@web.de

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 grep.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/grep.c b/grep.c
index cd952ef5d3..db6e0d895f 100644
--- a/grep.c
+++ b/grep.c
@@ -150,12 +150,20 @@ int grep_config(const char *var, const char *value, void *cb)
  * Initialize one instance of grep_opt and copy the
  * default values from the template we read the configuration
  * information in an earlier call to git_config(grep_config).
+ *
+ * If using PCRE, make sure that the library is configured
+ * to use the same allocator as Git (e.g. nedmalloc on Windows).
  */
 void grep_init(struct grep_opt *opt, struct repository *repo, const char *prefix)
 {
 	struct grep_opt *def = &grep_defaults;
 	int i;
 
+#ifdef USE_LIBPCRE1
+	pcre_malloc = malloc;
+	pcre_free = free;
+#endif
+
 	memset(opt, 0, sizeof(*opt));
 	opt->repo = repo;
 	opt->prefix = prefix;
-- 
gitgitgadget


  reply	other threads:[~2019-10-16 12:07 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-16 12:06 [PATCH 0/3] Revive 'pcre2-chartables-leakfix' Johannes Schindelin via GitGitGadget
2019-10-16 12:06 ` Carlo Marcelo Arenas Belón via GitGitGadget [this message]
2019-10-16 12:06 ` [PATCH 2/3] grep: make PCRE2 aware of custom allocator Carlo Marcelo Arenas Belón via GitGitGadget
2019-10-16 12:06 ` [PATCH 3/3] grep: avoid leak of chartables in PCRE2 Johannes Schindelin via GitGitGadget
2019-10-16 12:10 ` [PATCH v2 0/3] Revive 'pcre2-chartables-leakfix' Johannes Schindelin via GitGitGadget
2019-10-16 12:10   ` [PATCH v2 1/3] grep: make PCRE1 aware of custom allocator Carlo Marcelo Arenas Belón via GitGitGadget
2019-10-16 12:10   ` [PATCH v2 2/3] grep: make PCRE2 " Carlo Marcelo Arenas Belón via GitGitGadget
2019-10-18  1:38     ` Junio C Hamano
2021-02-04 21:05     ` [PATCH 00/10] grep/pcre2: memory allocation fixes Ævar Arnfjörð Bjarmason
2021-02-10 21:34       ` Junio C Hamano
2021-02-18  0:07       ` [PATCH v2 " Ævar Arnfjörð Bjarmason
2021-03-04  0:34         ` Junio C Hamano
2021-02-18  0:07       ` [PATCH v2 01/10] grep/pcre2: drop needless assignment + assert() on opt->pcre2 Ævar Arnfjörð Bjarmason
2021-02-18  0:07       ` [PATCH v2 02/10] grep/pcre2: drop needless assignment to NULL Ævar Arnfjörð Bjarmason
2021-02-18  0:07       ` [PATCH v2 03/10] grep/pcre2: correct reference to grep_init() in comment Ævar Arnfjörð Bjarmason
2021-02-18  0:07       ` [PATCH v2 04/10] grep/pcre2: prepare to add debugging to pcre2_malloc() Ævar Arnfjörð Bjarmason
2021-02-18  0:07       ` [PATCH v2 05/10] grep/pcre2: add GREP_PCRE2_DEBUG_MALLOC debug mode Ævar Arnfjörð Bjarmason
2021-02-18  0:07       ` [PATCH v2 06/10] grep/pcre2: use compile-time PCREv2 version test Ævar Arnfjörð Bjarmason
2021-03-04  0:14         ` Junio C Hamano
2021-02-18  0:07       ` [PATCH v2 07/10] grep/pcre2: use pcre2_maketables_free() function Ævar Arnfjörð Bjarmason
2021-02-18  0:07       ` [PATCH v2 08/10] grep/pcre2: actually make pcre2 use custom allocator Ævar Arnfjörð Bjarmason
2021-03-04  0:24         ` Junio C Hamano
2021-02-18  0:07       ` [PATCH v2 09/10] grep/pcre2: move back to thread-only PCREv2 structures Ævar Arnfjörð Bjarmason
2021-03-04  0:27         ` Junio C Hamano
2021-02-18  0:07       ` [PATCH v2 10/10] grep/pcre2: move definitions of pcre2_{malloc,free} Ævar Arnfjörð Bjarmason
2021-03-04  0:28         ` Junio C Hamano
2021-02-04 21:05     ` [PATCH 01/10] grep/pcre2: drop needless assignment + assert() on opt->pcre2 Ævar Arnfjörð Bjarmason
2021-02-04 21:05     ` [PATCH 02/10] grep/pcre2: drop needless assignment to NULL Ævar Arnfjörð Bjarmason
2021-02-04 21:05     ` [PATCH 03/10] grep/pcre2: correct reference to grep_init() in comment Ævar Arnfjörð Bjarmason
2021-02-04 21:05     ` [PATCH 04/10] grep/pcre2: prepare to add debugging to pcre2_malloc() Ævar Arnfjörð Bjarmason
2021-02-04 21:05     ` [PATCH 05/10] grep/pcre2: add GREP_PCRE2_DEBUG_MALLOC debug mode Ævar Arnfjörð Bjarmason
2021-02-10 10:38       ` Johannes Schindelin
2021-02-04 21:05     ` [PATCH 06/10] grep/pcre2: use compile-time PCREv2 version test Ævar Arnfjörð Bjarmason
2021-02-04 21:05     ` [PATCH 07/10] grep/pcre2: use pcre2_maketables_free() function Ævar Arnfjörð Bjarmason
2021-02-10 10:43       ` Johannes Schindelin
2021-03-04  0:16       ` Junio C Hamano
2021-02-04 21:05     ` [PATCH 08/10] grep/pcre2: actually make pcre2 use custom allocator Ævar Arnfjörð Bjarmason
2021-02-10 12:38       ` Johannes Schindelin
2021-02-04 21:05     ` [PATCH 09/10] grep/pcre2: move back to thread-only PCREv2 structures Ævar Arnfjörð Bjarmason
2021-02-04 21:05     ` [PATCH 10/10] grep/pcre2: move definitions of pcre2_{malloc,free} Ævar Arnfjörð Bjarmason
2021-02-10 12:40       ` Johannes Schindelin
2019-10-16 12:10   ` [PATCH v2 3/3] grep: avoid leak of chartables in PCRE2 Carlo Marcelo Arenas Belón via GitGitGadget
  -- strict thread matches above, loose matches on Subject: below --
2019-08-05 21:53 [PATCH 1/1] pcre2: allow overriding the system allocator Junio C Hamano
2019-08-06  8:50 ` [PATCH 0/3] grep: no leaks (WIP) Carlo Marcelo Arenas Belón
2019-08-06  8:50   ` [PATCH 1/3] grep: make PCRE1 aware of custom allocator Carlo Marcelo Arenas Belón
2019-08-08 13:54     ` Johannes Schindelin
2019-08-08 15:19       ` Carlo Arenas

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