[FFmpeg-devel] [PATCH v2 2/2] avutil/executor: Fix stack overflow due to recursive call

[FFmpeg-devel] [PATCH v2 2/2] avutil/executor: Fix stack overflow due to recursive call

[Zhao Zhili]

From: Zhao Zhili <zhilizhao@tencent.com>

av_executor_execute run the task directly when thread is disabled.
The task can schedule a new task by call av_executor_execute. This
forms an implicit recursive call. This patch removed the recursive
call.
---
v2: use bool type

 libavutil/executor.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libavutil/executor.c b/libavutil/executor.c
index 89058fab2f..bfce2ac444 100644
--- a/libavutil/executor.c
+++ b/libavutil/executor.c
@@ -20,6 +20,8 @@
 
 #include "config.h"
 
+#include <stdbool.h>
+
 #include "mem.h"
 #include "thread.h"
 
@@ -49,6 +51,7 @@ typedef struct ThreadInfo {
 struct AVExecutor {
     AVTaskCallbacks cb;
     int thread_count;
+    bool recursive;
 
     ThreadInfo *threads;
     uint8_t *local_contexts;
@@ -207,8 +210,12 @@ void av_executor_execute(AVExecutor *e, AVTask *t)
     }
 
     if (!e->thread_count || !HAVE_THREADS) {
+        if (e->recursive)
+            return;
+        e->recursive = true;
         // We are running in a single-threaded environment, so we must handle all tasks ourselves
         while (run_one_task(e, e->local_contexts))
             /* nothing */;
+        e->recursive = false;
     }
 }
-- 
2.42.0

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-devel] [PATCH v2 2/2] avutil/executor: Fix stack overflow due to recursive call

[Nuo Mi]

On Mon, Jul 8, 2024 at 8:14 PM Zhao Zhili <quinkblack@foxmail.com> wrote:

> From: Zhao Zhili <zhilizhao@tencent.com>
>
> av_executor_execute run the task directly when thread is disabled.
> The task can schedule a new task by call av_executor_execute. This
> forms an implicit recursive call. This patch removed the recursive
> call.
>
Thank you, Zhili.
LGTM
Using bool is a good idea.
We could also use bool for has_lock, has_cond, and die.


> ---
> v2: use bool type
>
>  libavutil/executor.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/libavutil/executor.c b/libavutil/executor.c
> index 89058fab2f..bfce2ac444 100644
> --- a/libavutil/executor.c
> +++ b/libavutil/executor.c
> @@ -20,6 +20,8 @@
>
>  #include "config.h"
>
> +#include <stdbool.h>
> +
>  #include "mem.h"
>  #include "thread.h"
>
> @@ -49,6 +51,7 @@ typedef struct ThreadInfo {
>  struct AVExecutor {
>      AVTaskCallbacks cb;
>      int thread_count;
> +    bool recursive;
>
>      ThreadInfo *threads;
>      uint8_t *local_contexts;
> @@ -207,8 +210,12 @@ void av_executor_execute(AVExecutor *e, AVTask *t)
>      }
>
>      if (!e->thread_count || !HAVE_THREADS) {
> +        if (e->recursive)
> +            return;
> +        e->recursive = true;
>          // We are running in a single-threaded environment, so we must
> handle all tasks ourselves
>          while (run_one_task(e, e->local_contexts))
>              /* nothing */;
> +        e->recursive = false;
>      }
>  }
> --
> 2.42.0
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".