[Qemu-devel] [PATCH for-4.0 v9 14/16] qemu_thread: supplement error handling for vnc_start_worker_thread

[Fei Li]

Supplement the error handling for vnc_thread_worker_thread: add
an Error parameter for it to propagate the error to its caller to
handle in case it fails, and make it return a Boolean to indicate
whether it succeeds.

Cc: Markus Armbruster <arm...@redhat.com>
Cc: Gerd Hoffmann <kra...@redhat.com>
Signed-off-by: Fei Li <f...@suse.com>
---
 ui/vnc-jobs.c | 17 +++++++++++------
 ui/vnc-jobs.h |  2 +-
 ui/vnc.c      |  4 +++-
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 5712f1f501..35a652d1fd 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -332,16 +332,21 @@ static bool vnc_worker_thread_running(void)
     return queue; /* Check global queue */
 }
 
-void vnc_start_worker_thread(void)
+bool vnc_start_worker_thread(Error **errp)
 {
     VncJobQueue *q;
 
-    if (vnc_worker_thread_running())
-        return ;
+    if (vnc_worker_thread_running()) {
+        goto out;
+    }
 
     q = vnc_queue_init();
-    /* TODO: let the further caller handle the error instead of abort() here */
-    qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread,
-                       q, QEMU_THREAD_DETACHED, &error_abort);
+    if (!qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread,
+                            q, QEMU_THREAD_DETACHED, errp)) {
+        vnc_queue_clear(q);
+        return false;
+    }
     queue = q; /* Set global queue */
+out:
+    return true;
 }
diff --git a/ui/vnc-jobs.h b/ui/vnc-jobs.h
index 59f66bcc35..14640593db 100644
--- a/ui/vnc-jobs.h
+++ b/ui/vnc-jobs.h
@@ -37,7 +37,7 @@ void vnc_job_push(VncJob *job);
 void vnc_jobs_join(VncState *vs);
 
 void vnc_jobs_consume_buffer(VncState *vs);
-void vnc_start_worker_thread(void);
+bool vnc_start_worker_thread(Error **errp);
 
 /* Locks */
 static inline int vnc_trylock_display(VncDisplay *vd)
diff --git a/ui/vnc.c b/ui/vnc.c
index 0c1b477425..0ffe9e6a5d 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3236,7 +3236,9 @@ void vnc_display_init(const char *id, Error **errp)
     vd->connections_limit = 32;
 
     qemu_mutex_init(&vd->mutex);
-    vnc_start_worker_thread();
+    if (!vnc_start_worker_thread(errp)) {
+        return;
+    }
 
     vd->dcl.ops = &dcl_ops;
     register_displaychangelistener(&vd->dcl);
-- 
2.13.7