hrev49371 adds 1 changeset to branch 'master'
old head: 29e8040d58b31033af8c095e3b2f5421197638d2
new head: db8517e2d7ecdd0e776cbcf5f5cb4d70f0f4d52f
overview:
http://cgit.haiku-os.org/haiku/log/?qt=range&q=db8517e2d7ec+%5E29e8040d58b3
----------------------------------------------------------------------------
db8517e2d7ec: netresolv: use thread-safe version of res functions
* Make getaddrinfo() and friends thread-safe by using the thread-safe
versions of the res functions.
* NetBSD offers two versions of the res functions: one in res_state.c
from the netresolv directory, defined as weak symbols. It is the
legacy version and only for single-threaded applications.
A thread-safe version of the functions is in res_state.c inside
their libpthread directory. An application that uses pthreads on
NetBSD will then use the non-weak symbols from the pthreads
library.
* On Haiku, the thread-safe version is now always used. The
res_state.c is taken from NetBSD's libpthread directory, and then
only struct _nres from the other file is added to it.
Please keep this in mind for future updates of netresolv, do not
accidentally replace it with the single-threaded version.
* This e.g. fixes WebPositive just hanging when opening websites
(even in situations where no IPv6-related problems apply), waiting
forever to resolve names.
[ Julian Harnath <julian.harnath@xxxxxxxxxxxxxx> ]
----------------------------------------------------------------------------
Revision: hrev49371
Commit: db8517e2d7ecdd0e776cbcf5f5cb4d70f0f4d52f
URL: http://cgit.haiku-os.org/haiku/commit/?id=db8517e2d7ec
Author: Julian Harnath <julian.harnath@xxxxxxxxxxxxxx>
Date: Sun Jul 5 11:26:02 2015 UTC
----------------------------------------------------------------------------
1 file changed, 90 insertions(+), 17 deletions(-)
src/kits/network/netresolv/resolv/res_state.c | 107 ++++++++++++++++++----
----------------------------------------------------------------------------
diff --git a/src/kits/network/netresolv/resolv/res_state.c
b/src/kits/network/netresolv/resolv/res_state.c
index 2f4cfe8..1ae60fc 100644
--- a/src/kits/network/netresolv/resolv/res_state.c
+++ b/src/kits/network/netresolv/resolv/res_state.c
@@ -1,4 +1,4 @@
-/* $NetBSD: res_state.c,v 1.8 2009/01/11 02:46:29 christos Exp $ */
+/* $NetBSD: res_state.c,v 1.6 2008/04/28 20:23:02 martin Exp $ */
/*-
* Copyright (c) 2004 The NetBSD Foundation, Inc.
@@ -28,17 +28,29 @@
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
+
+/* Note to Haiku Developers:
+ -------------------------
+ This file contains the thread-safe versions of res functions, taken from
+ NetBSD's libpthread directory. Do *not* replace it with the legacy
+ single-threaded version from NetBSD's netresolv directory.
+*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: res_state.c,v 1.8 2009/01/11 02:46:29 christos Exp $");
+__RCSID("$NetBSD: res_state.c,v 1.6 2008/04/28 20:23:02 martin Exp $");
#endif
#include <sys/types.h>
+#include <sys/queue.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
-#include <netdb.h>
+#include <stdlib.h>
+#include <unistd.h>
#include <resolv.h>
+#include <netdb.h>
+
+#include <pthread.h>
struct __res_state _nres
# if defined(__BIND_RES_TEXT)
@@ -46,30 +58,91 @@ struct __res_state _nres
# endif
;
-res_state __res_get_state_nothread(void);
-void __res_put_state_nothread(res_state);
+static SLIST_HEAD(, _res_st) res_list = LIST_HEAD_INITIALIZER(&res_list);
+
+struct _res_st {
+ /* __res_put_state() assumes st_res is the first member. */
+ struct __res_state st_res;
+
+ SLIST_ENTRY(_res_st) st_list;
+};
-#define __weak_alias(from, to) B_DEFINE_WEAK_ALIAS(to, from);
+static pthread_mutex_t res_mtx = PTHREAD_MUTEX_INITIALIZER;
-#ifdef __weak_alias
-__weak_alias(__res_get_state, __res_get_state_nothread)
-__weak_alias(__res_put_state, __res_put_state_nothread)
-/* Source compatibility; only for single threaded programs */
-__weak_alias(__res_state, __res_get_state_nothread)
+res_state __res_state(void);
+res_state __res_get_state(void);
+void __res_put_state(res_state);
+
+#ifdef RES_STATE_DEBUG
+static void
+res_state_debug(const char *msg, void *p)
+{
+ char buf[512];
+ pthread_t self = pthread__self();
+ int len = snprintf(buf, sizeof(buf), "%p: %s %p\n", self, msg, p);
+
+ (void)write(STDOUT_FILENO, buf, (size_t)len);
+}
+#else
+#define res_state_debug(a, b)
#endif
+
res_state
-__res_get_state_nothread(void)
+__res_get_state(void)
{
- if ((_nres.options & RES_INIT) == 0 && res_ninit(&_nres) == -1) {
- h_errno = NETDB_INTERNAL;
- return NULL;
+ res_state res;
+ struct _res_st *st;
+ pthread_mutex_lock(&res_mtx);
+ st = SLIST_FIRST(&res_list);
+ if (st != NULL) {
+ SLIST_REMOVE_HEAD(&res_list, st_list);
+ pthread_mutex_unlock(&res_mtx);
+ res = &st->st_res;
+ res_state_debug("checkout from list", st);
+ } else {
+ pthread_mutex_unlock(&res_mtx);
+ st = malloc(sizeof(*st));
+ if (st == NULL) {
+ h_errno = NETDB_INTERNAL;
+ return NULL;
+ }
+ res = &st->st_res;
+ res->options = 0;
+ res_state_debug("alloc new", res);
+ }
+ if ((res->options & RES_INIT) == 0) {
+ if (res_ninit(res) == -1) {
+ h_errno = NETDB_INTERNAL;
+ free(st);
+ return NULL;
+ }
}
- return &_nres;
+ return res;
}
void
/*ARGSUSED*/
-__res_put_state_nothread(res_state res)
+__res_put_state(res_state res)
+{
+ struct _res_st *st = (struct _res_st *)(void *)res;
+
+ res_state_debug("free", res);
+ pthread_mutex_lock(&res_mtx);
+ SLIST_INSERT_HEAD(&res_list, st, st_list);
+ pthread_mutex_unlock(&res_mtx);
+}
+
+/*
+ * This is aliased via a macro to _res; don't allow multi-threaded programs
+ * to use it.
+ */
+res_state
+__res_state(void)
{
+ static const char res[] = "_res is not supported for multi-threaded"
+ " programs.\n";
+ (void)write(STDERR_FILENO, res, sizeof(res) - 1);
+ abort();
+ return NULL;
}
