[PATCH v3 07/13] qio: Factor out helpers qio_net_listener_[un]watch

[Eric Blake <eblake@redhat.com>]

The code had three similar repetitions of an iteration over one or all
of nsiocs to set up a GSource, and likewise for teardown.  Since an
upcoming patch wants to tweak whether GSource or AioContext is used,
its better to consolidate that into one helper function for fewer
places to edit later.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v2: rebase to changes on the tracepoints earlier in series
v3: rebase to mutex protections, R-b dropped
---
 io/net-listener.c | 122 ++++++++++++++++++++--------------------------
 1 file changed, 52 insertions(+), 70 deletions(-)

diff --git a/io/net-listener.c b/io/net-listener.c
index 93100a2d253..9a94b153279 100644
--- a/io/net-listener.c
+++ b/io/net-listener.c
@@ -120,13 +120,54 @@ int qio_net_listener_open_sync(QIONetListener *listener,
     }
 }

+/*
+ * i == 0 to set watch on entire array, non-zero to only set watch on
+ * recent additions when earlier entries are already watched.
+ *
+ * listener->lock must be held by caller.
+ */
+static void
+qio_net_listener_watch(QIONetListener *listener, size_t i, const char *caller)
+{
+    if (!listener->io_func) {
+        return;
+    }
+
+    trace_qio_net_listener_watch(listener, listener->io_func,
+                                 listener->context, caller);
+    for ( ; i < listener->nsioc; i++) {
+        object_ref(OBJECT(listener));
+        listener->io_source[i] = qio_channel_add_watch_source(
+            QIO_CHANNEL(listener->sioc[i]), G_IO_IN,
+            qio_net_listener_channel_func,
+            listener, (GDestroyNotify)object_unref, listener->context);
+    }
+}
+
+/* listener->lock must be held by caller. */
+static void
+qio_net_listener_unwatch(QIONetListener *listener, const char *caller)
+{
+    size_t i;
+
+    if (!listener->io_func) {
+        return;
+    }
+
+    trace_qio_net_listener_unwatch(listener, listener->io_func,
+                                   listener->context, caller);
+    for (i = 0; i < listener->nsioc; i++) {
+        if (listener->io_source[i]) {
+            g_source_destroy(listener->io_source[i]);
+            g_source_unref(listener->io_source[i]);
+            listener->io_source[i] = NULL;
+        }
+    }
+}

 void qio_net_listener_add(QIONetListener *listener,
                           QIOChannelSocket *sioc)
 {
-    QIONetListenerClientFunc io_func;
-    GMainContext *context;
-
     if (listener->name) {
         qio_channel_set_name(QIO_CHANNEL(sioc), listener->name);
     }
@@ -142,21 +183,9 @@ void qio_net_listener_add(QIONetListener *listener,
     object_ref(OBJECT(sioc));
     listener->connected = true;

-    WITH_QEMU_LOCK_GUARD(&listener->lock) {
-        io_func = listener->io_func;
-        context = listener->context;
-    }
-
-    trace_qio_net_listener_watch(listener, io_func, context, "add");
-    if (io_func) {
-        object_ref(OBJECT(listener));
-        listener->io_source[listener->nsioc] = qio_channel_add_watch_source(
-            QIO_CHANNEL(listener->sioc[listener->nsioc]), G_IO_IN,
-            qio_net_listener_channel_func,
-            listener, (GDestroyNotify)object_unref, context);
-    }
-
+    QEMU_LOCK_GUARD(&listener->lock);
     listener->nsioc++;
+    qio_net_listener_watch(listener, listener->nsioc - 1, "add");
 }


@@ -166,25 +195,13 @@ void qio_net_listener_set_client_func_full(QIONetListener *listener,
                                            GDestroyNotify notify,
                                            GMainContext *context)
 {
-    size_t i;
-
     QEMU_LOCK_GUARD(&listener->lock);
     if (listener->io_func == func && listener->io_data == data &&
         listener->io_notify == notify && listener->context == context) {
         return;
     }

-    trace_qio_net_listener_unwatch(listener, listener->io_func,
-                                   listener->context, "set_client_func");
-
-    for (i = 0; i < listener->nsioc; i++) {
-        if (listener->io_source[i]) {
-            g_source_destroy(listener->io_source[i]);
-            g_source_unref(listener->io_source[i]);
-            listener->io_source[i] = NULL;
-        }
-    }
-
+    qio_net_listener_unwatch(listener, "set_client_func");
     if (listener->io_notify) {
         listener->io_notify(listener->io_data);
     }
@@ -193,17 +210,7 @@ void qio_net_listener_set_client_func_full(QIONetListener *listener,
     listener->io_notify = notify;
     listener->context = context;

-    trace_qio_net_listener_watch(listener, listener->io_func,
-                                 listener->context, "set_client_func");
-    if (listener->io_func != NULL) {
-        for (i = 0; i < listener->nsioc; i++) {
-            object_ref(OBJECT(listener));
-            listener->io_source[i] = qio_channel_add_watch_source(
-                QIO_CHANNEL(listener->sioc[i]), G_IO_IN,
-                qio_net_listener_channel_func,
-                listener, (GDestroyNotify)object_unref, context);
-        }
-    }
+    qio_net_listener_watch(listener, 0, "set_client_func");
 }

 void qio_net_listener_set_client_func(QIONetListener *listener,
@@ -254,21 +261,9 @@ QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener)
         .loop = loop
     };
     size_t i;
-    QIONetListenerClientFunc io_func;
-    GMainContext *context;

     WITH_QEMU_LOCK_GUARD(&listener->lock) {
-        io_func = listener->io_func;
-        context = listener->context;
-    }
-
-    trace_qio_net_listener_unwatch(listener, io_func, context, "wait_client");
-    for (i = 0; i < listener->nsioc; i++) {
-        if (listener->io_source[i]) {
-            g_source_destroy(listener->io_source[i]);
-            g_source_unref(listener->io_source[i]);
-            listener->io_source[i] = NULL;
-        }
+        qio_net_listener_unwatch(listener, "wait_client");
     }

     sources = g_new0(GSource *, listener->nsioc);
@@ -292,15 +287,8 @@ QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener)
     g_main_loop_unref(loop);
     g_main_context_unref(ctxt);

-    trace_qio_net_listener_watch(listener, io_func, context, "wait_client");
-    if (io_func != NULL) {
-        for (i = 0; i < listener->nsioc; i++) {
-            object_ref(OBJECT(listener));
-            listener->io_source[i] = qio_channel_add_watch_source(
-                QIO_CHANNEL(listener->sioc[i]), G_IO_IN,
-                qio_net_listener_channel_func,
-                listener, (GDestroyNotify)object_unref, context);
-        }
+    WITH_QEMU_LOCK_GUARD(&listener->lock) {
+        qio_net_listener_watch(listener, 0, "wait_client");
     }

     return data.sioc;
@@ -315,14 +303,8 @@ void qio_net_listener_disconnect(QIONetListener *listener)
     }

     QEMU_LOCK_GUARD(&listener->lock);
-    trace_qio_net_listener_unwatch(listener, listener->io_func,
-                                   listener->context, "disconnect");
+    qio_net_listener_unwatch(listener, "disconnect");
     for (i = 0; i < listener->nsioc; i++) {
-        if (listener->io_source[i]) {
-            g_source_destroy(listener->io_source[i]);
-            g_source_unref(listener->io_source[i]);
-            listener->io_source[i] = NULL;
-        }
         qio_channel_close(QIO_CHANNEL(listener->sioc[i]), NULL);
     }
     listener->connected = false;
-- 
2.51.1