[Mesa-dev] [PATCH 5/7] util/queue: hold a lock when reading num_threads in util_queue_finish

[Ian Romanick]

This patch is

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

On 11/28/18 6:59 PM, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> ---
>  src/util/u_queue.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/util/u_queue.c b/src/util/u_queue.c
> index 5aaf60ae78e..612ad5e83c6 100644
> --- a/src/util/u_queue.c
> +++ b/src/util/u_queue.c
> @@ -582,29 +582,29 @@ util_queue_finish_execute(void *data, int num_thread)
>     util_barrier_wait(barrier);
>  }
>  
>  /**
>   * Wait until all previously added jobs have completed.
>   */
>  void
>  util_queue_finish(struct util_queue *queue)
>  {
>     util_barrier barrier;
> -   struct util_queue_fence *fences = malloc(queue->num_threads * sizeof(*fences));
> -
> -   util_barrier_init(&barrier, queue->num_threads);
> +   struct util_queue_fence *fences;
>  
>     /* If 2 threads were adding jobs for 2 different barries at the same time,
>      * a deadlock would happen, because 1 barrier requires that all threads
>      * wait for it exclusively.
>      */
>     mtx_lock(&queue->finish_lock);
> +   fences = malloc(queue->num_threads * sizeof(*fences));
> +   util_barrier_init(&barrier, queue->num_threads);
>  
>     for (unsigned i = 0; i < queue->num_threads; ++i) {
>        util_queue_fence_init(&fences[i]);
>        util_queue_add_job(queue, &barrier, &fences[i], util_queue_finish_execute, NULL);
>     }
>  
>     for (unsigned i = 0; i < queue->num_threads; ++i) {
>        util_queue_fence_wait(&fences[i]);
>        util_queue_fence_destroy(&fences[i]);
>     }
>