core: Merge malloc_trim patch

We've had multiple opportunities where Richard Mudgett's
malloc_trim patch has been useful. Let's get it
pushed up to gerrit and merged.

Since malloc_trim is only available in libc, an entry is
added to configure.ac to create a definition for
HAVE_MALLOC_TRIM.

Change-Id: Ia38308c550149d9d6eae4ca414a649957de9700c

configure

@@ -16847,7 +16847,7 @@ fi
 done
 
 
-for ac_func in asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl
+for ac_func in asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl malloc_trim
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"

configure.ac

@@ -784,7 +784,7 @@ AC_FUNC_STRNLEN
 AC_FUNC_STRTOD
 AC_FUNC_UTIME_NULL
 AC_FUNC_VPRINTF
-AC_CHECK_FUNCS([asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl])
+AC_CHECK_FUNCS([asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl malloc_trim])
 
 AC_MSG_CHECKING(for htonll)
 AC_LINK_IFELSE(

include/asterisk/autoconfig.h.in

@@ -492,6 +492,9 @@
 /* Define to 1 if you have the <malloc.h> header file. */
 #undef HAVE_MALLOC_H
 
+/* Define to 1 if you have the `malloc_trim' function. */
+#undef HAVE_MALLOC_TRIM
+
 /* Define to 1 if you have the <math.h> header file. */
 #undef HAVE_MATH_H
 

main/cli.c

@@ -1788,6 +1788,34 @@ static char *handle_cli_wait_fullybooted(struct ast_cli_entry *e, int cmd, struc
 	return CLI_SUCCESS;
 }
 
+
+#ifdef HAVE_MALLOC_TRIM
+	/* BUGBUG malloc_trim() is a libc specific function.  Non-portable. */
+	static char *handle_cli_malloc_trim(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+	{
+		extern int malloc_trim(size_t __pad) __THROW;
+
+		switch (cmd) {
+		case CLI_INIT:
+			e->command = "malloc trim";
+			e->usage =
+				"Usage: malloc trim\n"
+				"       Try to give excess memory back to the OS.\n";
+			return NULL;
+		case CLI_GENERATE:
+			return NULL;
+		}
+
+		if (malloc_trim(0)) {
+			ast_cli(a->fd, "Returned some memory to the OS.\n");
+		} else {
+			ast_cli(a->fd, "No memory returned to the OS.\n");
+		}
+
+		return CLI_SUCCESS;
+	}
+#endif
+
 static char *handle_help(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 
 static struct ast_cli_entry cli_cli[] = {
@@ -1833,6 +1861,11 @@ static struct ast_cli_entry cli_cli[] = {
 	AST_CLI_DEFINE(handle_cli_check_permissions, "Try a permissions config for a user"),
 
 	AST_CLI_DEFINE(handle_cli_wait_fullybooted, "Wait for Asterisk to be fully booted"),
+
+#ifdef HAVE_MALLOC_TRIM
+	AST_CLI_DEFINE(handle_cli_malloc_trim, "Return excess memory to the OS"),
+#endif
+
 };
 
 /*!