[PATCH v3 11/33] block/nbd: rename NBDConnectThread to NBDClientConnection

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

We are going to move connection code to own file and want clear names
and APIs.

The structure is shared between user and (possibly) several runs of
connect-thread. So it's wrong to call it "thread". Let's rename to
something more generic.

Appropriately rename connect_thread and thr variables to conn.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/nbd.c | 137 ++++++++++++++++++++++++++--------------------------
 1 file changed, 68 insertions(+), 69 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index dab73bdf3b..9ce6a323eb 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -66,7 +66,7 @@ typedef enum NBDClientState {
     NBD_CLIENT_QUIT
 } NBDClientState;
 
-typedef struct NBDConnectThread {
+typedef struct NBDClientConnection {
     /* Initialization constants */
     SocketAddress *saddr; /* address to connect to */
 
@@ -82,7 +82,7 @@ typedef struct NBDConnectThread {
     bool running; /* thread is running now */
     bool detached; /* thread is detached and should cleanup the state */
     Coroutine *wait_co; /* nbd_co_establish_connection() wait in yield() */
-} NBDConnectThread;
+} NBDClientConnection;
 
 typedef struct BDRVNBDState {
     QIOChannelSocket *sioc; /* The master data channel */
@@ -115,34 +115,34 @@ typedef struct BDRVNBDState {
     char *x_dirty_bitmap;
     bool alloc_depth;
 
-    NBDConnectThread *connect_thread;
+    NBDClientConnection *conn;
 } BDRVNBDState;
 
-static void nbd_free_connect_thread(NBDConnectThread *thr);
+static void nbd_free_connect_thread(NBDClientConnection *conn);
 static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr,
                                     Error **errp);
 static coroutine_fn QIOChannelSocket *
-nbd_co_establish_connection(NBDConnectThread *thr, Error **errp);
-static void nbd_co_establish_connection_cancel(NBDConnectThread *thr);
+nbd_co_establish_connection(NBDClientConnection *conn, Error **errp);
+static void nbd_co_establish_connection_cancel(NBDClientConnection *conn);
 static int nbd_client_handshake(BlockDriverState *bs, Error **errp);
 static void nbd_yank(void *opaque);
 
 static void nbd_clear_bdrvstate(BlockDriverState *bs)
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
-    NBDConnectThread *thr = s->connect_thread;
+    NBDClientConnection *conn = s->conn;
     bool do_free;
 
-    qemu_mutex_lock(&thr->mutex);
-    if (thr->running) {
-        thr->detached = true;
+    qemu_mutex_lock(&conn->mutex);
+    if (conn->running) {
+        conn->detached = true;
     }
-    do_free = !thr->running && !thr->detached;
-    qemu_mutex_unlock(&thr->mutex);
+    do_free = !conn->running && !conn->detached;
+    qemu_mutex_unlock(&conn->mutex);
 
     /* the runaway thread will clean it up itself */
     if (do_free) {
-        nbd_free_connect_thread(thr);
+        nbd_free_connect_thread(conn);
     }
 
     yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name));
@@ -286,7 +286,7 @@ static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs)
         qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
     }
 
-    nbd_co_establish_connection_cancel(s->connect_thread);
+    nbd_co_establish_connection_cancel(s->conn);
 
     reconnect_delay_timer_del(s);
 
@@ -326,7 +326,7 @@ static void nbd_teardown_connection(BlockDriverState *bs)
         if (s->connection_co_sleep_ns_state) {
             qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
         }
-        nbd_co_establish_connection_cancel(s->connect_thread);
+        nbd_co_establish_connection_cancel(s->conn);
     }
     if (qemu_in_coroutine()) {
         s->teardown_co = qemu_coroutine_self();
@@ -353,101 +353,101 @@ static bool nbd_client_connecting_wait(BDRVNBDState *s)
 
 static void nbd_init_connect_thread(BDRVNBDState *s)
 {
-    s->connect_thread = g_new(NBDConnectThread, 1);
+    s->conn = g_new(NBDClientConnection, 1);
 
-    *s->connect_thread = (NBDConnectThread) {
+    *s->conn = (NBDClientConnection) {
         .saddr = QAPI_CLONE(SocketAddress, s->saddr),
     };
 
-    qemu_mutex_init(&s->connect_thread->mutex);
+    qemu_mutex_init(&s->conn->mutex);
 }
 
-static void nbd_free_connect_thread(NBDConnectThread *thr)
+static void nbd_free_connect_thread(NBDClientConnection *conn)
 {
-    if (thr->sioc) {
-        qio_channel_close(QIO_CHANNEL(thr->sioc), NULL);
-        object_unref(OBJECT(thr->sioc));
+    if (conn->sioc) {
+        qio_channel_close(QIO_CHANNEL(conn->sioc), NULL);
+        object_unref(OBJECT(conn->sioc));
     }
-    error_free(thr->err);
-    qapi_free_SocketAddress(thr->saddr);
-    g_free(thr);
+    error_free(conn->err);
+    qapi_free_SocketAddress(conn->saddr);
+    g_free(conn);
 }
 
 static void *connect_thread_func(void *opaque)
 {
-    NBDConnectThread *thr = opaque;
+    NBDClientConnection *conn = opaque;
     int ret;
     bool do_free = false;
 
-    thr->sioc = qio_channel_socket_new();
+    conn->sioc = qio_channel_socket_new();
 
-    error_free(thr->err);
-    thr->err = NULL;
-    ret = qio_channel_socket_connect_sync(thr->sioc, thr->saddr, &thr->err);
+    error_free(conn->err);
+    conn->err = NULL;
+    ret = qio_channel_socket_connect_sync(conn->sioc, conn->saddr, &conn->err);
     if (ret < 0) {
-        object_unref(OBJECT(thr->sioc));
-        thr->sioc = NULL;
+        object_unref(OBJECT(conn->sioc));
+        conn->sioc = NULL;
     }
 
-    qemu_mutex_lock(&thr->mutex);
+    qemu_mutex_lock(&conn->mutex);
 
-    assert(thr->running);
-    thr->running = false;
-    if (thr->wait_co) {
-        aio_co_schedule(NULL, thr->wait_co);
-        thr->wait_co = NULL;
+    assert(conn->running);
+    conn->running = false;
+    if (conn->wait_co) {
+        aio_co_schedule(NULL, conn->wait_co);
+        conn->wait_co = NULL;
     }
-    do_free = thr->detached;
+    do_free = conn->detached;
 
-    qemu_mutex_unlock(&thr->mutex);
+    qemu_mutex_unlock(&conn->mutex);
 
     if (do_free) {
-        nbd_free_connect_thread(thr);
+        nbd_free_connect_thread(conn);
     }
 
     return NULL;
 }
 
 /*
- * Get a new connection in context of @thr:
+ * Get a new connection in context of @conn:
  *   if thread is running, wait for completion
  *   if thread is already succeeded in background, and user didn't get the
  *     result, just return it now
  *   otherwise if thread is not running, start a thread and wait for completion
  */
 static coroutine_fn QIOChannelSocket *
-nbd_co_establish_connection(NBDConnectThread *thr, Error **errp)
+nbd_co_establish_connection(NBDClientConnection *conn, Error **errp)
 {
     QIOChannelSocket *sioc = NULL;
     QemuThread thread;
 
-    qemu_mutex_lock(&thr->mutex);
+    qemu_mutex_lock(&conn->mutex);
 
     /*
      * Don't call nbd_co_establish_connection() in several coroutines in
      * parallel. Only one call at once is supported.
      */
-    assert(!thr->wait_co);
+    assert(!conn->wait_co);
 
-    if (!thr->running) {
-        if (thr->sioc) {
+    if (!conn->running) {
+        if (conn->sioc) {
             /* Previous attempt finally succeeded in background */
-            sioc = g_steal_pointer(&thr->sioc);
-            qemu_mutex_unlock(&thr->mutex);
+            sioc = g_steal_pointer(&conn->sioc);
+            qemu_mutex_unlock(&conn->mutex);
 
             return sioc;
         }
 
-        thr->running = true;
-        error_free(thr->err);
-        thr->err = NULL;
+        conn->running = true;
+        error_free(conn->err);
+        conn->err = NULL;
         qemu_thread_create(&thread, "nbd-connect",
-                           connect_thread_func, thr, QEMU_THREAD_DETACHED);
+                           connect_thread_func, conn, QEMU_THREAD_DETACHED);
     }
 
-    thr->wait_co = qemu_coroutine_self();
+    conn->wait_co = qemu_coroutine_self();
 
-    qemu_mutex_unlock(&thr->mutex);
+    qemu_mutex_unlock(&conn->mutex);
 
     /*
      * We are going to wait for connect-thread finish, but
@@ -455,9 +455,9 @@ nbd_co_establish_connection(NBDConnectThread *thr, Error **errp)
      */
     qemu_coroutine_yield();
 
-    qemu_mutex_lock(&thr->mutex);
+    qemu_mutex_lock(&conn->mutex);
 
-    if (thr->running) {
+    if (conn->running) {
         /*
          * Obviously, drained section wants to start. Report the attempt as
          * failed. Still connect thread is executing in background, and its
@@ -465,12 +465,12 @@ nbd_co_establish_connection(NBDConnectThread *thr, Error **errp)
          */
         error_setg(errp, "Connection attempt cancelled by other operation");
     } else {
-        error_propagate(errp, thr->err);
-        thr->err = NULL;
-        sioc = g_steal_pointer(&thr->sioc);
+        error_propagate(errp, conn->err);
+        conn->err = NULL;
+        sioc = g_steal_pointer(&conn->sioc);
     }
 
-    qemu_mutex_unlock(&thr->mutex);
+    qemu_mutex_unlock(&conn->mutex);
 
     return sioc;
 }
@@ -481,17 +481,16 @@ nbd_co_establish_connection(NBDConnectThread *thr, Error **errp)
  * stop the thread itself neither close the socket. It just safely wakes
  * nbd_co_establish_connection() sleeping in the yield().
  */
-static void nbd_co_establish_connection_cancel(NBDConnectThread *thr)
+static void nbd_co_establish_connection_cancel(NBDClientConnection *conn)
 {
-    qemu_mutex_lock(&thr->mutex);
+    qemu_mutex_lock(&conn->mutex);
 
-    if (thr->wait_co) {
-        aio_co_schedule(NULL, thr->wait_co);
-        thr->wait_co = NULL;
+    if (conn->wait_co) {
+        aio_co_schedule(NULL, conn->wait_co);
+        conn->wait_co = NULL;
     }
 
-    qemu_mutex_unlock(&thr->mutex);
-
+    qemu_mutex_unlock(&conn->mutex);
 }
 
 static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
@@ -537,7 +536,7 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
         s->ioc = NULL;
     }
 
-    s->sioc = nbd_co_establish_connection(s->connect_thread, NULL);
+    s->sioc = nbd_co_establish_connection(s->conn, NULL);
     if (!s->sioc) {
         ret = -ECONNREFUSED;
         goto out;
-- 
2.29.2