Re: [PATCH v5 8/8] convert: Update subprocess_read_status to not die on EOF

[Lars Schneider]

> On 07 Apr 2017, at 14:03, Ben Peart  wrote:
> 
> Enable sub-processes to gracefully handle when the process dies by
> updating subprocess_read_status to return an error on EOF instead of
> dying.
> 
> Update apply_multi_file_filter to take advantage of the revised
> subprocess_read_status.
> 
> Signed-off-by: Ben Peart 
> ---
> convert.c | 10 --
> sub-process.c | 10 +++---
> sub-process.h |  2 +-
> 3 files changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/convert.c b/convert.c
> index baa41da760..9e181e27ad 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -629,7 +629,10 @@ static int apply_multi_file_filter(const char *path, 
> const char *src, size_t len
>   if (err)
>   goto done;
> 
> - subprocess_read_status(process->out, _status);
> + err = subprocess_read_status(process->out, _status);
> + if (err)
> + goto done;
> +
>   err = strcmp(filter_status.buf, "success");
>   if (err)
>   goto done;
> @@ -638,7 +641,10 @@ static int apply_multi_file_filter(const char *path, 
> const char *src, size_t len
>   if (err)
>   goto done;
> 
> - subprocess_read_status(process->out, _status);
> + err = subprocess_read_status(process->out, _status);
> + if (err)
> + goto done;
> +
>   err = strcmp(filter_status.buf, "success");
> 
> done:
> diff --git a/sub-process.c b/sub-process.c
> index 60bb650012..c5057cafcd 100644
> --- a/sub-process.c
> +++ b/sub-process.c
> @@ -30,13 +30,15 @@ struct subprocess_entry *subprocess_find_entry(const char 
> *cmd)
>   return hashmap_get(_map, , NULL);
> }
> 
> -void subprocess_read_status(int fd, struct strbuf *status)
> +int subprocess_read_status(int fd, struct strbuf *status)
> {
>   struct strbuf **pair;
>   char *line;
> + int len;
> +
>   for (;;) {
> - line = packet_read_line(fd, NULL);
> - if (!line)
> + len = packet_read_line_gently(fd, NULL, );
> + if ((len == -1) || !line)

Minor nit: Maybe "if ((len < 0) || !line)" ?


>   break;
>   pair = strbuf_split_str(line, '=', 2);
>   if (pair[0] && pair[0]->len && pair[1]) {
> @@ -48,6 +50,8 @@ void subprocess_read_status(int fd, struct strbuf *status)
>   }
>   strbuf_list_free(pair);
>   }
> +
> + return len == -1 ? len : 0;

Minor nit: Maybe "return len < 0 ? len : 0;

> }
> 
> void subprocess_stop(struct subprocess_entry *entry)
> diff --git a/sub-process.h b/sub-process.h
> index 0cf1760a0a..5a1ce0 100644
> --- a/sub-process.h
> +++ b/sub-process.h
> @@ -41,6 +41,6 @@ static inline struct child_process 
> *subprocess_get_child_process(
>  * key/value pairs and return the value from the last "status" packet
>  */
> 
> -void subprocess_read_status(int fd, struct strbuf *status);
> +int subprocess_read_status(int fd, struct strbuf *status);
> 
> #endif
> -- 
> 2.12.0.windows.1.31.g1548525701.dirty
> 

Looks good to me.

Thanks,
Lars

[PATCH v5 8/8] convert: Update subprocess_read_status to not die on EOF

[Ben Peart]

Enable sub-processes to gracefully handle when the process dies by
updating subprocess_read_status to return an error on EOF instead of
dying.

Update apply_multi_file_filter to take advantage of the revised
subprocess_read_status.

Signed-off-by: Ben Peart 
---
 convert.c | 10 --
 sub-process.c | 10 +++---
 sub-process.h |  2 +-
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/convert.c b/convert.c
index baa41da760..9e181e27ad 100644
--- a/convert.c
+++ b/convert.c
@@ -629,7 +629,10 @@ static int apply_multi_file_filter(const char *path, const 
char *src, size_t len
if (err)
goto done;
 
-   subprocess_read_status(process->out, _status);
+   err = subprocess_read_status(process->out, _status);
+   if (err)
+   goto done;
+
err = strcmp(filter_status.buf, "success");
if (err)
goto done;
@@ -638,7 +641,10 @@ static int apply_multi_file_filter(const char *path, const 
char *src, size_t len
if (err)
goto done;
 
-   subprocess_read_status(process->out, _status);
+   err = subprocess_read_status(process->out, _status);
+   if (err)
+   goto done;
+
err = strcmp(filter_status.buf, "success");
 
 done:
diff --git a/sub-process.c b/sub-process.c
index 60bb650012..c5057cafcd 100644
--- a/sub-process.c
+++ b/sub-process.c
@@ -30,13 +30,15 @@ struct subprocess_entry *subprocess_find_entry(const char 
*cmd)
return hashmap_get(_map, , NULL);
 }
 
-void subprocess_read_status(int fd, struct strbuf *status)
+int subprocess_read_status(int fd, struct strbuf *status)
 {
struct strbuf **pair;
char *line;
+   int len;
+
for (;;) {
-   line = packet_read_line(fd, NULL);
-   if (!line)
+   len = packet_read_line_gently(fd, NULL, );
+   if ((len == -1) || !line)
break;
pair = strbuf_split_str(line, '=', 2);
if (pair[0] && pair[0]->len && pair[1]) {
@@ -48,6 +50,8 @@ void subprocess_read_status(int fd, struct strbuf *status)
}
strbuf_list_free(pair);
}
+
+   return len == -1 ? len : 0;
 }
 
 void subprocess_stop(struct subprocess_entry *entry)
diff --git a/sub-process.h b/sub-process.h
index 0cf1760a0a..5a1ce0 100644
--- a/sub-process.h
+++ b/sub-process.h
@@ -41,6 +41,6 @@ static inline struct child_process 
*subprocess_get_child_process(
  * key/value pairs and return the value from the last "status" packet
  */
 
-void subprocess_read_status(int fd, struct strbuf *status);
+int subprocess_read_status(int fd, struct strbuf *status);
 
 #endif
-- 
2.12.0.windows.1.31.g1548525701.dirty