[Qemu-devel] [PATCH 04/18] char: add wait support for reconnect

[marcandre . lureau]

From: Marc-André Lureau <address@hidden>

Until now, 'wait' was solely used for listening sockets. However, it can
also be useful for 'reconnect' socket kind, where the first open must
succeed before continuing.

This allows for instance (with other support patches) having vhost-user
wait for an initial connection to setup the vhost-net, before eventually
accepting new connections.

Signed-off-by: Marc-André Lureau <address@hidden>
---
 qemu-char.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/qemu-char.c b/qemu-char.c
index 8702931..3e25c08 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -3659,7 +3659,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
ChardevBackend *backend,
                                   Error **errp)
 {
     bool is_listen      = qemu_opt_get_bool(opts, "server", false);
-    bool is_waitconnect = is_listen && qemu_opt_get_bool(opts, "wait", true);
+    bool is_wait        = qemu_opt_get_bool(opts, "wait", is_listen);
     bool is_telnet      = qemu_opt_get_bool(opts, "telnet", false);
     bool do_nodelay     = !qemu_opt_get_bool(opts, "delay", true);
     int64_t reconnect   = qemu_opt_get_number(opts, "reconnect", 0);
@@ -3696,7 +3696,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
ChardevBackend *backend,
     sock->has_telnet = true;
     sock->telnet = is_telnet;
     sock->has_wait = true;
-    sock->wait = is_waitconnect;
+    sock->wait = is_wait;
     sock->has_reconnect = true;
     sock->reconnect = reconnect;
     sock->tls_creds = g_strdup(tls_creds);
@@ -4350,7 +4350,7 @@ static CharDriverState *qmp_chardev_open_socket(const 
char *id,
     bool do_nodelay     = sock->has_nodelay ? sock->nodelay : false;
     bool is_listen      = sock->has_server  ? sock->server  : true;
     bool is_telnet      = sock->has_telnet  ? sock->telnet  : false;
-    bool is_waitconnect = sock->has_wait    ? sock->wait    : false;
+    bool is_wait        = sock->has_wait    ? sock->wait    : false;
     int64_t reconnect   = sock->has_reconnect ? sock->reconnect : 0;
     ChardevCommon *common = qapi_ChardevSocket_base(sock);
     QIOChannelSocket *sioc = NULL;
@@ -4424,7 +4424,7 @@ static CharDriverState *qmp_chardev_open_socket(const 
char *id,
     }
 
     sioc = qio_channel_socket_new();
-    if (s->reconnect_time) {
+    if (s->reconnect_time && !is_wait) {
         qio_channel_socket_connect_async(sioc, s->addr,
                                          qemu_chr_socket_connected,
                                          chr, NULL);
@@ -4433,7 +4433,7 @@ static CharDriverState *qmp_chardev_open_socket(const 
char *id,
             goto error;
         }
         s->listen_ioc = sioc;
-        if (is_waitconnect) {
+        if (is_wait) {
             trace_char_socket_waiting(chr->filename);
             tcp_chr_accept(QIO_CHANNEL(s->listen_ioc), G_IO_IN, chr);
         }
@@ -4443,9 +4443,24 @@ static CharDriverState *qmp_chardev_open_socket(const 
char *id,
                 QIO_CHANNEL(s->listen_ioc), G_IO_IN, tcp_chr_accept, chr, 
NULL);
         }
     } else {
-        if (qio_channel_socket_connect_sync(sioc, s->addr, errp) < 0) {
-            goto error;
-        }
+        do {
+            Error *err = NULL;
+
+            if (qio_channel_socket_connect_sync(sioc, s->addr, &err) < 0) {
+                if (reconnect) {
+                    trace_char_socket_reconnect_error(chr->label,
+                                                      error_get_pretty(err));
+                    error_free(err);
+                    continue;
+                } else {
+                    error_propagate(errp, err);
+                    goto error;
+                }
+            } else {
+                break;
+            }
+        } while (true);
+
         tcp_chr_new_client(chr, sioc);
         object_unref(OBJECT(sioc));
     }
-- 
2.5.5