[SR-Dev] git:ser_core_cvs: Wrapper functions for regcomp, regexec, regfree, and regerror using shared
Andrei Pelinescu-Onciul
andrei at iptel.org
Fri Apr 3 16:05:10 CEST 2009
Module: sip-router
Branch: ser_core_cvs
Commit: e01a458045ad4363110dad04a774342a57b5851a
URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=e01a458045ad4363110dad04a774342a57b5851a
Author: Miklos Tirpak <miklos at iptel.org>
Committer: Miklos Tirpak <miklos at iptel.org>
Date: Fri Apr 3 13:03:46 2009 +0000
Wrapper functions for regcomp, regexec, regfree, and regerror using shared
memory allocators instead of libc malloc/realloc/free.
Check the README file for more details.
---
lib/Makefile | 2 +-
lib/README | 22 ++++++--
lib/shm_regex/Makefile | 14 +++++
lib/shm_regex/README | 23 ++++++++
lib/shm_regex/shm_regex.c | 129 +++++++++++++++++++++++++++++++++++++++++++++
lib/shm_regex/shm_regex.h | 45 ++++++++++++++++
6 files changed, 228 insertions(+), 7 deletions(-)
diff --git a/lib/Makefile b/lib/Makefile
index 431e37d..01bbc1d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -7,7 +7,7 @@
#
-SUBDIRS=binrpc cds xcap presence
+SUBDIRS=binrpc cds xcap presence shm_regex
.PHONY: subdirs $(SUBDIRS)
diff --git a/lib/README b/lib/README
index 289b9f6..317fd3e 100644
--- a/lib/README
+++ b/lib/README
@@ -24,28 +24,32 @@ xcap - Common XCAP operations and structures (XCAP authorization documents
requires external libraries: libxml2, libcurl3 (nonSER version)
requires internal libraries: cds
+shm_regex - Wrapper functions for regcomp, regexec, regfree and regerror
+ using shared memory. See 'man regex' for details.
+
Used by modules: pa, rls, dialog, rpa
Usage:
-----
-All libraries can be compiled "with ser" or "without ser". Compilation
-without ser may be useful for debugging purposes or for example for
+All libraries except shm_regex can be compiled "with ser" or "without ser".
+Compilation without ser may be useful for debugging purposes or for example for
searching for memory leaks with some tool like valgrind.
+shm_regex library can be compiled only with ser.
Compilation with ser:
--------------------
Compilation and installation of these libraries is NOT DONE by running
-main ser makefile now - it MUST be done MANUALLY. For this purpose
-is there Makefile.ser. To compile and install libraries simply run
+main ser makefile now - it MUST be done MANUALLY. To compile and install
+libraries simply run
- make -f Makefile.ser install
+ make install
in lib directory. You can select destination directory like in the case
of ser, for example:
- make -f Makefile.ser install prefix="/my/ser/directory"
+ make install prefix="/my/ser/directory"
AFTER COMPILATION of libraries you can COMPILE MODULES using this
libraries like PA, RLS or dialog.
@@ -61,6 +65,12 @@ you should set LD_LIBRARY_PATH=/usr/local/lib/ser. In the case of
nonstandard installation, you can use something like
LD_LIBRARY_PATH=/my/ser/directory/lib/ser.
+Compilation without ser:
+--------------------
+Use the alternate makefile, Makefile.noser:
+
+ make -f Makefile.noser install
+
Documentation
-------------
Documentation for all libraries is (or will be) in
diff --git a/lib/shm_regex/Makefile b/lib/shm_regex/Makefile
new file mode 100644
index 0000000..2a0c907
--- /dev/null
+++ b/lib/shm_regex/Makefile
@@ -0,0 +1,14 @@
+#
+# makefile for shm_regex
+#
+
+include ../../Makefile.defs
+auto_gen=
+NAME:=ser_shm_regex
+MAJOR_VER=0
+MINOR_VER=1
+BUGFIX_VER=0
+LIBS=
+
+include ../../Makefile.libs
+
diff --git a/lib/shm_regex/README b/lib/shm_regex/README
new file mode 100644
index 0000000..bfec807
--- /dev/null
+++ b/lib/shm_regex/README
@@ -0,0 +1,23 @@
+$Id$
+
+Wrapper functions for regcomp, regexec, regfree, and regerror using shared
+memory allocators instead of libc malloc/realloc/free. The original functions
+are prefixed with "shm_".
+
+The regular expression compiled with shm_regcomp() can be used with shm_regexec()
+simultaneously by multiple processes without locking, because regexec has its own
+internal locks. It can be later on freed with shm_regfree() when the expression
+is no longer used. Note however that
+
+1) shm_regexec allocates shared memory for the pattern buffer when it is successfully
+called for the first time.
+
+2) shm_regexec temporary allocates and deallocates memory for storing the registers
+for the pmatch array runtime if nmatch and pmatch parameters are not 0. This is
+done also in shared memory, therefore use the shared memory wrappers for
+regular expression based search-and-replace only if really necessary.
+
+See 'man regex' for the usage and parameters of the functions.
+
+Supported only with GNU C library.
+
diff --git a/lib/shm_regex/shm_regex.c b/lib/shm_regex/shm_regex.c
new file mode 100644
index 0000000..165d535
--- /dev/null
+++ b/lib/shm_regex/shm_regex.c
@@ -0,0 +1,129 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2009 iptelorg GmbH
+ *
+ * This file is part of ser, a free SIP server.
+ *
+ * ser is free software; you can redistribute it and/or modify
+ * it under the terms of 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
+ *
+ * For a license to use the ser software under conditions
+ * other than those described here, or to purchase support for this
+ * software, please contact iptel.org by e-mail at the following addresses:
+ * info at iptel.org
+ *
+ * ser 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 a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * History
+ * -------
+ * 2009-04-03 Initial version (Miklos)
+ */
+
+#include <malloc.h> /* hook prototypes */
+
+#include "../../mem/shm_mem.h"
+#include "shm_regex.h"
+
+typedef void *(malloc_hook_t) (size_t, const void *);
+typedef void *(realloc_hook_t) (void *, size_t, const void *);
+typedef void (free_hook_t) (void *, const void *);
+
+/* The memory hooks are overwritten before calling regcomp(), regfree(),
+ * and regexec(), and shared memory function are called
+ * from the hooks instead of libc malloc/realloc/free.
+ */
+
+static void *shm_malloc_hook(size_t size, const void *caller)
+{
+ return shm_malloc (size);
+}
+
+static void *shm_realloc_hook(void *p, size_t size, const void *caller)
+{
+ return shm_realloc (p, size);
+}
+
+static void shm_free_hook(void *ptr, const void *caller)
+{
+ if (ptr) shm_free (ptr);
+}
+
+#define replace_malloc_hooks() \
+ do { \
+ orig_malloc_hook = __malloc_hook; \
+ orig_realloc_hook = __realloc_hook; \
+ orig_free_hook = __free_hook; \
+ __malloc_hook = shm_malloc_hook; \
+ __realloc_hook = shm_realloc_hook; \
+ __free_hook = shm_free_hook; \
+ } while (0)
+
+#define restore_malloc_hooks() \
+ do { \
+ __malloc_hook = orig_malloc_hook; \
+ __realloc_hook = orig_realloc_hook; \
+ __free_hook = orig_free_hook; \
+ } while (0)
+
+int shm_regcomp(regex_t *preg, const char *regex, int cflags)
+{
+ malloc_hook_t *orig_malloc_hook;
+ realloc_hook_t *orig_realloc_hook;
+ free_hook_t *orig_free_hook;
+ int ret;
+
+ replace_malloc_hooks();
+ ret = regcomp(preg, regex, cflags);
+ restore_malloc_hooks();
+
+ return ret;
+}
+
+void shm_regfree(regex_t *preg)
+{
+ malloc_hook_t *orig_malloc_hook;
+ realloc_hook_t *orig_realloc_hook;
+ free_hook_t *orig_free_hook;
+
+ replace_malloc_hooks();
+ regfree(preg);
+ restore_malloc_hooks();
+}
+
+int shm_regexec(const regex_t *preg, const char *string, size_t nmatch,
+ regmatch_t pmatch[], int eflags)
+{
+ malloc_hook_t *orig_malloc_hook;
+ realloc_hook_t *orig_realloc_hook;
+ free_hook_t *orig_free_hook;
+ int ret;
+
+ /* regexec() allocates some memory for the pattern buffer
+ * when it is successfully called for the first time, therefore
+ * shared memory is required also here.
+ * The drawback is that shared memory allocation is also used
+ * needlessly for allocating the temporary space for
+ * the elements of pmatch. -- Does not happen if pmatch and
+ * nmatch are 0.
+ * It is safe to call regexec() concurrently without locking,
+ * because regexec() has its own locks.
+ * (Miklos)
+ */
+ replace_malloc_hooks();
+ ret = regexec(preg, string, nmatch,
+ pmatch, eflags);
+ restore_malloc_hooks();
+
+ return ret;
+}
+
diff --git a/lib/shm_regex/shm_regex.h b/lib/shm_regex/shm_regex.h
new file mode 100644
index 0000000..42ec52b
--- /dev/null
+++ b/lib/shm_regex/shm_regex.h
@@ -0,0 +1,45 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2009 iptelorg GmbH
+ *
+ * This file is part of ser, a free SIP server.
+ *
+ * ser is free software; you can redistribute it and/or modify
+ * it under the terms of 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
+ *
+ * For a license to use the ser software under conditions
+ * other than those described here, or to purchase support for this
+ * software, please contact iptel.org by e-mail at the following addresses:
+ * info at iptel.org
+ *
+ * ser 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 a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * History
+ * -------
+ * 2009-04-03 Initial version (Miklos)
+ */
+
+#ifndef _SHM_REGEX_H
+#define _SHM_REGEX_H
+
+#include <sys/types.h>
+#include <regex.h>
+
+int shm_regcomp(regex_t *preg, const char *regex, int cflags);
+void shm_regfree(regex_t *preg);
+int shm_regexec(const regex_t *preg, const char *string, size_t nmatch,
+ regmatch_t pmatch[], int eflags);
+
+#define shm_regerror regerror
+
+#endif /* _SHM_REGEX_H */
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