[Qemu-devel] [RFC 4/6] migration: return incoming task tag for fd

[Peter Xu <peterx@redhat.com>]

Allow to return the task tag in fd_start_incoming_migration().

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/fd.c | 18 +++++++++++-------
 migration/fd.h |  2 +-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/migration/fd.c b/migration/fd.c
index 30f5258..e9a548c 100644
--- a/migration/fd.c
+++ b/migration/fd.c
@@ -52,7 +52,11 @@ static gboolean fd_accept_incoming_migration(QIOChannel *ioc,
     return FALSE; /* unregister */
 }
 
-void fd_start_incoming_migration(const char *infd, Error **errp)
+/*
+ * Returns the tag ID of the watch that is attached to global main
+ * loop (>0), or zero if failure detected.
+ */
+guint fd_start_incoming_migration(const char *infd, Error **errp)
 {
     QIOChannel *ioc;
     int fd;
@@ -63,13 +67,13 @@ void fd_start_incoming_migration(const char *infd, Error **errp)
     ioc = qio_channel_new_fd(fd, errp);
     if (!ioc) {
         close(fd);
-        return;
+        return 0;
     }
 
     qio_channel_set_name(QIO_CHANNEL(ioc), "migration-fd-incoming");
-    qio_channel_add_watch(ioc,
-                          G_IO_IN,
-                          fd_accept_incoming_migration,
-                          NULL,
-                          NULL);
+    return qio_channel_add_watch(ioc,
+                                 G_IO_IN,
+                                 fd_accept_incoming_migration,
+                                 NULL,
+                                 NULL);
 }
diff --git a/migration/fd.h b/migration/fd.h
index a14a63c..94cdea8 100644
--- a/migration/fd.h
+++ b/migration/fd.h
@@ -16,7 +16,7 @@
 
 #ifndef QEMU_MIGRATION_FD_H
 #define QEMU_MIGRATION_FD_H
-void fd_start_incoming_migration(const char *path, Error **errp);
+guint fd_start_incoming_migration(const char *path, Error **errp);
 
 void fd_start_outgoing_migration(MigrationState *s, const char *fdname,
                                  Error **errp);
-- 
2.7.4