Re: [Spice-devel] [PATCH v3 1/7] Add red_qxl_destroy function

[Jonathon Jongsma]

On Fri, 2016-12-02 at 10:51 -0500, Frediano Ziglio wrote:
> > 
> > 
> > On Fri, 2016-12-02 at 03:35 -0500, Frediano Ziglio wrote:
> > > 
> > > > 
> > > > 
> > > > 
> > > > On Thu, 2016-12-01 at 11:09 +, Frediano Ziglio wrote:
> > > > > 
> > > > > 
> > > > > Allows to destroy a QXL object
> > > > > 
> > > > > Signed-off-by: Frediano Ziglio 
> > > > > ---
> > > > >  server/red-qxl.c| 25 ++---
> > > > >  server/red-qxl.h|  1 +
> > > > >  server/red-worker.c | 35 ++-
> > > > >  server/red-worker.h |  1 +
> > > > >  4 files changed, 58 insertions(+), 4 deletions(-)
> > > > > 
> > > > > diff --git a/server/red-qxl.c b/server/red-qxl.c
> > > > > index 19cff95..de0546f 100644
> > > > > --- a/server/red-qxl.c
> > > > > +++ b/server/red-qxl.c
> > > > > @@ -58,6 +58,7 @@ struct QXLState {
> > > > >  QXLDevSurfaceCreate surface_create;
> > > > >  unsigned int max_monitors;
> > > > >  RedsState *reds;
> > > > > +RedWorker *worker;
> > > > >  
> > > > >  pthread_mutex_t scanout_mutex;
> > > > >  SpiceMsgDisplayGlScanoutUnix scanout;
> > > > > @@ -1006,11 +1007,29 @@ void red_qxl_init(RedsState *reds,
> > > > > QXLInstance *qxl)
> > > > >  client_display_cbs.disconnect =
> > > > > red_qxl_disconnect_display_peer;
> > > > >  client_display_cbs.migrate = red_qxl_display_migrate;
> > > > >  
> > > > > -// TODO: reference and free
> > > > > -RedWorker *worker = red_worker_new(qxl,
> > > > > _cursor_cbs,
> > > > > +qxl_state->worker = red_worker_new(qxl,
> > > > > _cursor_cbs,
> > > > > _display_cbs);
> > > > >  
> > > > > -red_worker_run(worker);
> > > > > +red_worker_run(qxl_state->worker);
> > > > > +}
> > > > > +
> > > > > +void red_qxl_destroy(QXLInstance *qxl)
> > > > > +{
> > > > > +spice_return_if_fail(qxl->st != NULL && qxl->st-
> > > > > >dispatcher
> > > > > !=
> > > > > NULL);
> > > > > +
> > > > > +QXLState *qxl_state = qxl->st;
> > > > > +
> > > > > +/* send message to close thread */
> > > > > +RedWorkerMessageClose message;
> > > > > +dispatcher_send_message(qxl_state->dispatcher,
> > > > > +RED_WORKER_MESSAGE_CLOSE_WORKER,
> > > > > +);
> > > > > +red_worker_free(qxl_state->worker);
> > > > 
> > > > Is this safe? You're sending a CLOSE_WORKER message and then
> > > > freeing
> > > > the worker. But the CLOSE_WORKER handler (handle_dev_close())
> > > > also
> > > > uses
> > > > the worker (via 'opaque'). I don't think we can guarantee that
> > > > the
> > > > RedWorker's handler has executed already, can we?
> > > > 
> > > 
> > > red_worker_free calls pthread_join to make sure consistency.
> > 
> > Hmm, somehow I missed that. Thanks. Is it worth asserting or
> > warning if
> > red_worker_free() is called from the worker thread?
> > 
> > Acked-by: Jonathon Jongsma 
> > 
> 
> Maybe some comments would be better. It's true that RedQxl and
> RedWorker
> are quite close friends and only RedQxl should use RedWorker.
> I'll try to write the comment:
> 
> > 
> > 
> > > 
> > >  
> > > > 
> > > > 
> > > > > 
> > > > > 
> > > > > +g_object_unref(qxl_state->dispatcher);
> > > > > +/* this must be done after calling red_worker_free */
> > > > > +qxl->st = NULL;
> > > > > +pthread_mutex_destroy(_state->scanout_mutex);
> > > > > +free(qxl_state);
> > > > >  }
> > > > >  
> > > > >  Dispatcher *red_qxl_get_dispatcher(QXLInstance *qxl)
> > > > > diff --git a/server/red-qxl.h b/server/red-qxl.h
> > > > > index 65357b1..7743124 100644
> > > > > --- a/server/red-qxl.h
> > > > > +++ b/server/red-qxl.h
> > > > > @@ -24,6 +24,7 @@
> > > > >  typedef struct AsyncCommand AsyncCommand;
> > > > >  
> > > > >  void red_qxl_init(SpiceServer *reds, QXLInstance *qxl);
> > > > > +void red_qxl_destroy(QXLInstance *qxl);
> > > > >  
> > > > >  void red_qxl_on_ic_change(QXLInstance *qxl,
> > > > > SpiceImageCompression
> > > > > ic);
> > > > >  void red_qxl_on_sv_change(QXLInstance *qxl, int sv);
> > > > > diff --git a/server/red-worker.c b/server/red-worker.c
> > > > > index d699bd6..5dac0ec 100644
> > > > > --- a/server/red-worker.c
> > > > > +++ b/server/red-worker.c
> > > > > @@ -1410,7 +1410,6 @@ static void *red_worker_main(void *arg)
> > > > >  g_main_loop_unref(loop);
> > > > >  worker->loop = NULL;
> > > > >  
> > > > > -/* FIXME: free worker, and join threads */
> > > > >  return NULL;
> > > > >  }
> > > > >  
> > > > > @@ -1435,3 +1434,37 @@ bool red_worker_run(RedWorker *worker)
> > > > >  
> > > > >  return r == 0;
> > > > >  }
> > > > > +
> > > > > +static void red_worker_close_channel(RedChannel *channel)
> > > > > +{
> > > > > +red_channel_reset_thread_id(channel);
> > > > > +red_channel_destroy(channel);
> > > > > +}
> > > > > +
> 
> /*
>  * Free the worker thread. This function should be called by RedQxl
>  

Re: [Spice-devel] [PATCH v3 1/7] Add red_qxl_destroy function

[Frediano Ziglio]

> 
> On Fri, 2016-12-02 at 03:35 -0500, Frediano Ziglio wrote:
> > > 
> > > 
> > > On Thu, 2016-12-01 at 11:09 +, Frediano Ziglio wrote:
> > > > 
> > > > Allows to destroy a QXL object
> > > > 
> > > > Signed-off-by: Frediano Ziglio 
> > > > ---
> > > >  server/red-qxl.c| 25 ++---
> > > >  server/red-qxl.h|  1 +
> > > >  server/red-worker.c | 35 ++-
> > > >  server/red-worker.h |  1 +
> > > >  4 files changed, 58 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/server/red-qxl.c b/server/red-qxl.c
> > > > index 19cff95..de0546f 100644
> > > > --- a/server/red-qxl.c
> > > > +++ b/server/red-qxl.c
> > > > @@ -58,6 +58,7 @@ struct QXLState {
> > > >  QXLDevSurfaceCreate surface_create;
> > > >  unsigned int max_monitors;
> > > >  RedsState *reds;
> > > > +RedWorker *worker;
> > > >  
> > > >  pthread_mutex_t scanout_mutex;
> > > >  SpiceMsgDisplayGlScanoutUnix scanout;
> > > > @@ -1006,11 +1007,29 @@ void red_qxl_init(RedsState *reds,
> > > > QXLInstance *qxl)
> > > >  client_display_cbs.disconnect =
> > > > red_qxl_disconnect_display_peer;
> > > >  client_display_cbs.migrate = red_qxl_display_migrate;
> > > >  
> > > > -// TODO: reference and free
> > > > -RedWorker *worker = red_worker_new(qxl, _cursor_cbs,
> > > > +qxl_state->worker = red_worker_new(qxl, _cursor_cbs,
> > > > _display_cbs);
> > > >  
> > > > -red_worker_run(worker);
> > > > +red_worker_run(qxl_state->worker);
> > > > +}
> > > > +
> > > > +void red_qxl_destroy(QXLInstance *qxl)
> > > > +{
> > > > +spice_return_if_fail(qxl->st != NULL && qxl->st->dispatcher
> > > > !=
> > > > NULL);
> > > > +
> > > > +QXLState *qxl_state = qxl->st;
> > > > +
> > > > +/* send message to close thread */
> > > > +RedWorkerMessageClose message;
> > > > +dispatcher_send_message(qxl_state->dispatcher,
> > > > +RED_WORKER_MESSAGE_CLOSE_WORKER,
> > > > +);
> > > > +red_worker_free(qxl_state->worker);
> > > 
> > > Is this safe? You're sending a CLOSE_WORKER message and then
> > > freeing
> > > the worker. But the CLOSE_WORKER handler (handle_dev_close()) also
> > > uses
> > > the worker (via 'opaque'). I don't think we can guarantee that the
> > > RedWorker's handler has executed already, can we?
> > > 
> > 
> > red_worker_free calls pthread_join to make sure consistency.
> 
> Hmm, somehow I missed that. Thanks. Is it worth asserting or warning if
> red_worker_free() is called from the worker thread?
> 
> Acked-by: Jonathon Jongsma 
> 

Maybe some comments would be better. It's true that RedQxl and RedWorker
are quite close friends and only RedQxl should use RedWorker.
I'll try to write the comment:

> 
> >  
> > > 
> > > > 
> > > > +g_object_unref(qxl_state->dispatcher);
> > > > +/* this must be done after calling red_worker_free */
> > > > +qxl->st = NULL;
> > > > +pthread_mutex_destroy(_state->scanout_mutex);
> > > > +free(qxl_state);
> > > >  }
> > > >  
> > > >  Dispatcher *red_qxl_get_dispatcher(QXLInstance *qxl)
> > > > diff --git a/server/red-qxl.h b/server/red-qxl.h
> > > > index 65357b1..7743124 100644
> > > > --- a/server/red-qxl.h
> > > > +++ b/server/red-qxl.h
> > > > @@ -24,6 +24,7 @@
> > > >  typedef struct AsyncCommand AsyncCommand;
> > > >  
> > > >  void red_qxl_init(SpiceServer *reds, QXLInstance *qxl);
> > > > +void red_qxl_destroy(QXLInstance *qxl);
> > > >  
> > > >  void red_qxl_on_ic_change(QXLInstance *qxl,
> > > > SpiceImageCompression
> > > > ic);
> > > >  void red_qxl_on_sv_change(QXLInstance *qxl, int sv);
> > > > diff --git a/server/red-worker.c b/server/red-worker.c
> > > > index d699bd6..5dac0ec 100644
> > > > --- a/server/red-worker.c
> > > > +++ b/server/red-worker.c
> > > > @@ -1410,7 +1410,6 @@ static void *red_worker_main(void *arg)
> > > >  g_main_loop_unref(loop);
> > > >  worker->loop = NULL;
> > > >  
> > > > -/* FIXME: free worker, and join threads */
> > > >  return NULL;
> > > >  }
> > > >  
> > > > @@ -1435,3 +1434,37 @@ bool red_worker_run(RedWorker *worker)
> > > >  
> > > >  return r == 0;
> > > >  }
> > > > +
> > > > +static void red_worker_close_channel(RedChannel *channel)
> > > > +{
> > > > +red_channel_reset_thread_id(channel);
> > > > +red_channel_destroy(channel);
> > > > +}
> > > > +

/*
 * Free the worker thread. This function should be called by RedQxl
 * after sending a RED_WORKER_MESSAGE_CLOSE_WORKER message;
 * failing to do so will cause a deadlock.
 */

> > > > +void red_worker_free(RedWorker *worker)
> > > > +{
> > > > +RedsState *reds = red_qxl_get_server(worker->qxl->st);
> > > > +
> > > > +/* prevent any possible future attempt to connect to new
> > > > clients
> > > > */
> > > > +reds_unregister_channel(reds, RED_CHANNEL(worker-
> > > > > 
> > > > > 

Re: [Spice-devel] [PATCH v3 1/7] Add red_qxl_destroy function

[Jonathon Jongsma]

On Fri, 2016-12-02 at 03:35 -0500, Frediano Ziglio wrote:
> > 
> > 
> > On Thu, 2016-12-01 at 11:09 +, Frediano Ziglio wrote:
> > > 
> > > Allows to destroy a QXL object
> > > 
> > > Signed-off-by: Frediano Ziglio 
> > > ---
> > >  server/red-qxl.c| 25 ++---
> > >  server/red-qxl.h|  1 +
> > >  server/red-worker.c | 35 ++-
> > >  server/red-worker.h |  1 +
> > >  4 files changed, 58 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/server/red-qxl.c b/server/red-qxl.c
> > > index 19cff95..de0546f 100644
> > > --- a/server/red-qxl.c
> > > +++ b/server/red-qxl.c
> > > @@ -58,6 +58,7 @@ struct QXLState {
> > >  QXLDevSurfaceCreate surface_create;
> > >  unsigned int max_monitors;
> > >  RedsState *reds;
> > > +RedWorker *worker;
> > >  
> > >  pthread_mutex_t scanout_mutex;
> > >  SpiceMsgDisplayGlScanoutUnix scanout;
> > > @@ -1006,11 +1007,29 @@ void red_qxl_init(RedsState *reds,
> > > QXLInstance *qxl)
> > >  client_display_cbs.disconnect =
> > > red_qxl_disconnect_display_peer;
> > >  client_display_cbs.migrate = red_qxl_display_migrate;
> > >  
> > > -// TODO: reference and free
> > > -RedWorker *worker = red_worker_new(qxl, _cursor_cbs,
> > > +qxl_state->worker = red_worker_new(qxl, _cursor_cbs,
> > > _display_cbs);
> > >  
> > > -red_worker_run(worker);
> > > +red_worker_run(qxl_state->worker);
> > > +}
> > > +
> > > +void red_qxl_destroy(QXLInstance *qxl)
> > > +{
> > > +spice_return_if_fail(qxl->st != NULL && qxl->st->dispatcher
> > > !=
> > > NULL);
> > > +
> > > +QXLState *qxl_state = qxl->st;
> > > +
> > > +/* send message to close thread */
> > > +RedWorkerMessageClose message;
> > > +dispatcher_send_message(qxl_state->dispatcher,
> > > +RED_WORKER_MESSAGE_CLOSE_WORKER,
> > > +);
> > > +red_worker_free(qxl_state->worker);
> > 
> > Is this safe? You're sending a CLOSE_WORKER message and then
> > freeing
> > the worker. But the CLOSE_WORKER handler (handle_dev_close()) also
> > uses
> > the worker (via 'opaque'). I don't think we can guarantee that the
> > RedWorker's handler has executed already, can we?
> > 
> 
> red_worker_free calls pthread_join to make sure consistency.

Hmm, somehow I missed that. Thanks. Is it worth asserting or warning if
red_worker_free() is called from the worker thread?

Acked-by: Jonathon Jongsma 


>  
> > 
> > > 
> > > +g_object_unref(qxl_state->dispatcher);
> > > +/* this must be done after calling red_worker_free */
> > > +qxl->st = NULL;
> > > +pthread_mutex_destroy(_state->scanout_mutex);
> > > +free(qxl_state);
> > >  }
> > >  
> > >  Dispatcher *red_qxl_get_dispatcher(QXLInstance *qxl)
> > > diff --git a/server/red-qxl.h b/server/red-qxl.h
> > > index 65357b1..7743124 100644
> > > --- a/server/red-qxl.h
> > > +++ b/server/red-qxl.h
> > > @@ -24,6 +24,7 @@
> > >  typedef struct AsyncCommand AsyncCommand;
> > >  
> > >  void red_qxl_init(SpiceServer *reds, QXLInstance *qxl);
> > > +void red_qxl_destroy(QXLInstance *qxl);
> > >  
> > >  void red_qxl_on_ic_change(QXLInstance *qxl,
> > > SpiceImageCompression
> > > ic);
> > >  void red_qxl_on_sv_change(QXLInstance *qxl, int sv);
> > > diff --git a/server/red-worker.c b/server/red-worker.c
> > > index d699bd6..5dac0ec 100644
> > > --- a/server/red-worker.c
> > > +++ b/server/red-worker.c
> > > @@ -1410,7 +1410,6 @@ static void *red_worker_main(void *arg)
> > >  g_main_loop_unref(loop);
> > >  worker->loop = NULL;
> > >  
> > > -/* FIXME: free worker, and join threads */
> > >  return NULL;
> > >  }
> > >  
> > > @@ -1435,3 +1434,37 @@ bool red_worker_run(RedWorker *worker)
> > >  
> > >  return r == 0;
> > >  }
> > > +
> > > +static void red_worker_close_channel(RedChannel *channel)
> > > +{
> > > +red_channel_reset_thread_id(channel);
> > > +red_channel_destroy(channel);
> > > +}
> > > +
> > > +void red_worker_free(RedWorker *worker)
> > > +{
> > > +RedsState *reds = red_qxl_get_server(worker->qxl->st);
> > > +
> > > +/* prevent any possible future attempt to connect to new
> > > clients
> > > */
> > > +reds_unregister_channel(reds, RED_CHANNEL(worker-
> > > > 
> > > > cursor_channel));
> > > +reds_unregister_channel(reds, RED_CHANNEL(worker-
> > > > 
> > > > display_channel));
> > > +
> > > +pthread_join(worker->thread, NULL);
> > > +
> > > +red_worker_close_channel(RED_CHANNEL(worker-
> > > >cursor_channel));
> > > +worker->cursor_channel = NULL;
> > > +red_worker_close_channel(RED_CHANNEL(worker-
> > > >display_channel));
> > > +worker->display_channel = NULL;
> > > +
> > > +if (worker->dispatch_watch) {
> > > +worker->core.watch_remove(>core, worker-
> > > > 
> > > > dispatch_watch);
> > > +}
> > > +
> > > +

Re: [Spice-devel] [PATCH v3 1/7] Add red_qxl_destroy function

[Frediano Ziglio]

> 
> On Thu, 2016-12-01 at 11:09 +, Frediano Ziglio wrote:
> > Allows to destroy a QXL object
> > 
> > Signed-off-by: Frediano Ziglio 
> > ---
> >  server/red-qxl.c| 25 ++---
> >  server/red-qxl.h|  1 +
> >  server/red-worker.c | 35 ++-
> >  server/red-worker.h |  1 +
> >  4 files changed, 58 insertions(+), 4 deletions(-)
> > 
> > diff --git a/server/red-qxl.c b/server/red-qxl.c
> > index 19cff95..de0546f 100644
> > --- a/server/red-qxl.c
> > +++ b/server/red-qxl.c
> > @@ -58,6 +58,7 @@ struct QXLState {
> >  QXLDevSurfaceCreate surface_create;
> >  unsigned int max_monitors;
> >  RedsState *reds;
> > +RedWorker *worker;
> >  
> >  pthread_mutex_t scanout_mutex;
> >  SpiceMsgDisplayGlScanoutUnix scanout;
> > @@ -1006,11 +1007,29 @@ void red_qxl_init(RedsState *reds,
> > QXLInstance *qxl)
> >  client_display_cbs.disconnect = red_qxl_disconnect_display_peer;
> >  client_display_cbs.migrate = red_qxl_display_migrate;
> >  
> > -// TODO: reference and free
> > -RedWorker *worker = red_worker_new(qxl, _cursor_cbs,
> > +qxl_state->worker = red_worker_new(qxl, _cursor_cbs,
> > _display_cbs);
> >  
> > -red_worker_run(worker);
> > +red_worker_run(qxl_state->worker);
> > +}
> > +
> > +void red_qxl_destroy(QXLInstance *qxl)
> > +{
> > +spice_return_if_fail(qxl->st != NULL && qxl->st->dispatcher !=
> > NULL);
> > +
> > +QXLState *qxl_state = qxl->st;
> > +
> > +/* send message to close thread */
> > +RedWorkerMessageClose message;
> > +dispatcher_send_message(qxl_state->dispatcher,
> > +RED_WORKER_MESSAGE_CLOSE_WORKER,
> > +);
> > +red_worker_free(qxl_state->worker);
> 
> Is this safe? You're sending a CLOSE_WORKER message and then freeing
> the worker. But the CLOSE_WORKER handler (handle_dev_close()) also uses
> the worker (via 'opaque'). I don't think we can guarantee that the
> RedWorker's handler has executed already, can we?
>

red_worker_free calls pthread_join to make sure consistency.
 
> > +g_object_unref(qxl_state->dispatcher);
> > +/* this must be done after calling red_worker_free */
> > +qxl->st = NULL;
> > +pthread_mutex_destroy(_state->scanout_mutex);
> > +free(qxl_state);
> >  }
> >  
> >  Dispatcher *red_qxl_get_dispatcher(QXLInstance *qxl)
> > diff --git a/server/red-qxl.h b/server/red-qxl.h
> > index 65357b1..7743124 100644
> > --- a/server/red-qxl.h
> > +++ b/server/red-qxl.h
> > @@ -24,6 +24,7 @@
> >  typedef struct AsyncCommand AsyncCommand;
> >  
> >  void red_qxl_init(SpiceServer *reds, QXLInstance *qxl);
> > +void red_qxl_destroy(QXLInstance *qxl);
> >  
> >  void red_qxl_on_ic_change(QXLInstance *qxl, SpiceImageCompression
> > ic);
> >  void red_qxl_on_sv_change(QXLInstance *qxl, int sv);
> > diff --git a/server/red-worker.c b/server/red-worker.c
> > index d699bd6..5dac0ec 100644
> > --- a/server/red-worker.c
> > +++ b/server/red-worker.c
> > @@ -1410,7 +1410,6 @@ static void *red_worker_main(void *arg)
> >  g_main_loop_unref(loop);
> >  worker->loop = NULL;
> >  
> > -/* FIXME: free worker, and join threads */
> >  return NULL;
> >  }
> >  
> > @@ -1435,3 +1434,37 @@ bool red_worker_run(RedWorker *worker)
> >  
> >  return r == 0;
> >  }
> > +
> > +static void red_worker_close_channel(RedChannel *channel)
> > +{
> > +red_channel_reset_thread_id(channel);
> > +red_channel_destroy(channel);
> > +}
> > +
> > +void red_worker_free(RedWorker *worker)
> > +{
> > +RedsState *reds = red_qxl_get_server(worker->qxl->st);
> > +
> > +/* prevent any possible future attempt to connect to new clients
> > */
> > +reds_unregister_channel(reds, RED_CHANNEL(worker-
> > >cursor_channel));
> > +reds_unregister_channel(reds, RED_CHANNEL(worker-
> > >display_channel));
> > +
> > +pthread_join(worker->thread, NULL);
> > +
> > +red_worker_close_channel(RED_CHANNEL(worker->cursor_channel));
> > +worker->cursor_channel = NULL;
> > +red_worker_close_channel(RED_CHANNEL(worker->display_channel));
> > +worker->display_channel = NULL;
> > +
> > +if (worker->dispatch_watch) {
> > +worker->core.watch_remove(>core, worker-
> > >dispatch_watch);
> > +}
> > +
> > +g_main_context_unref(worker->core.main_context);
> > +
> > +if (worker->record) {
> > +red_record_free(worker->record);
> > +}
> > +memslot_info_destroy(>mem_slots);
> > +free(worker);
> > +}
> > diff --git a/server/red-worker.h b/server/red-worker.h
> > index 53b92b3..d5b5a78 100644
> > --- a/server/red-worker.h
> > +++ b/server/red-worker.h
> > @@ -29,5 +29,6 @@ RedWorker* red_worker_new(QXLInstance *qxl,
> >    const ClientCbs *client_cursor_cbs,
> >    const ClientCbs *client_display_cbs);
> >  bool   red_worker_run(RedWorker