Re: [libgpiod][PATCH 1/3] tests: don't use the same chip object from different threads

["Erik Schilling" <erik.schilling@xxxxxxxxxx>]

On Tue Sep 19, 2023 at 11:31 AM CEST, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> There are no thread-safety guarantees in libgpiod. Let's not reuse the
> chip object created in one thread to generate info events in another but
> create a second chip for that purpose instead.
>
> Reported-by: Erik Schilling <erik.schilling@xxxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Reviewed-by: Erik Schilling <erik.schilling@xxxxxxxxxx>

> ---
>  tests/tests-info-event.c | 62 +++++++++++++++++++++-------------------
>  1 file changed, 33 insertions(+), 29 deletions(-)
>
> diff --git a/tests/tests-info-event.c b/tests/tests-info-event.c
> index d069811..cbd9e9e 100644
> --- a/tests/tests-info-event.c
> +++ b/tests/tests-info-event.c
> @@ -49,43 +49,59 @@ GPIOD_TEST_CASE(event_timeout)
>  }
>  
>  struct request_ctx {
> -	struct gpiod_chip *chip;
> -	struct gpiod_line_config *line_cfg;
> -	struct gpiod_line_settings *settings;
> +	const char *path;
>  	guint offset;
>  };
>  
>  static gpointer request_reconfigure_release_line(gpointer data)
>  {
> +	g_autoptr(struct_gpiod_line_settings) settings = NULL;
> +	g_autoptr(struct_gpiod_line_config) line_cfg = NULL;
>  	g_autoptr(struct_gpiod_line_request) request = NULL;
> +	g_autoptr(struct_gpiod_chip) chip = NULL;
>  	struct request_ctx *ctx = data;
>  	gint ret;
>  
> +	chip = gpiod_chip_open(ctx->path);
> +	g_assert_nonnull(chip);
> +	if (g_test_failed())
> +		return NULL;
> +
> +	line_cfg = gpiod_line_config_new();
> +	g_assert_nonnull(line_cfg);
> +	if (g_test_failed())
> +		return NULL;
> +
> +	settings = gpiod_line_settings_new();
> +	g_assert_nonnull(settings);
> +	if (g_test_failed())
> +		return NULL;
> +
>  	g_usleep(1000);
>  
> -	ret = gpiod_line_config_add_line_settings(ctx->line_cfg, &ctx->offset,
> -						  1, ctx->settings);
> +	ret = gpiod_line_config_add_line_settings(line_cfg, &ctx->offset,
> +						  1, settings);
>  	g_assert_cmpint(ret, ==, 0);
>  	if (g_test_failed())
>  		return NULL;
>  
> -	request = gpiod_chip_request_lines(ctx->chip, NULL, ctx->line_cfg);
> +	request = gpiod_chip_request_lines(chip, NULL, line_cfg);
>  	g_assert_nonnull(request);
>  	if (g_test_failed())
>  		return NULL;
>  
>  	g_usleep(1000);
>  
> -	gpiod_line_config_reset(ctx->line_cfg);
> -	gpiod_line_settings_set_direction(ctx->settings,
> +	gpiod_line_config_reset(line_cfg);
> +	gpiod_line_settings_set_direction(settings,
>  					  GPIOD_LINE_DIRECTION_OUTPUT);
> -	ret = gpiod_line_config_add_line_settings(ctx->line_cfg, &ctx->offset,
> -						  1, ctx->settings);
> +	ret = gpiod_line_config_add_line_settings(line_cfg, &ctx->offset,
> +						  1, settings);
>  	g_assert_cmpint(ret, ==, 0);
>  	if (g_test_failed())
>  		return NULL;
>  
> -	ret = gpiod_line_request_reconfigure_lines(request, ctx->line_cfg);
> +	ret = gpiod_line_request_reconfigure_lines(request, line_cfg);
>  	g_assert_cmpint(ret, ==, 0);
>  	if (g_test_failed())
>  		return NULL;
> @@ -106,25 +122,19 @@ GPIOD_TEST_CASE(request_reconfigure_release_events)
>  	g_autoptr(struct_gpiod_info_event) request_event = NULL;
>  	g_autoptr(struct_gpiod_info_event) reconfigure_event = NULL;
>  	g_autoptr(struct_gpiod_info_event) release_event = NULL;
> -	g_autoptr(struct_gpiod_line_config) line_cfg = NULL;
> -	g_autoptr(struct_gpiod_line_settings) settings = NULL;
>  	g_autoptr(GThread) thread = NULL;
>  	struct gpiod_line_info *request_info, *reconfigure_info, *release_info;
>  	guint64 request_ts, reconfigure_ts, release_ts;
>  	struct request_ctx ctx;
> +	const char *chip_path = g_gpiosim_chip_get_dev_path(sim);
>  	gint ret;
>  
> -	chip = gpiod_test_open_chip_or_fail(g_gpiosim_chip_get_dev_path(sim));
> -	line_cfg = gpiod_test_create_line_config_or_fail();
> -	settings = gpiod_test_create_line_settings_or_fail();
> -
> +	chip = gpiod_test_open_chip_or_fail(chip_path);
>  	info = gpiod_test_chip_watch_line_info_or_fail(chip, 3);
>  
>  	g_assert_false(gpiod_line_info_is_used(info));
>  
> -	ctx.chip = chip;
> -	ctx.line_cfg = line_cfg;
> -	ctx.settings = settings;
> +	ctx.path = chip_path;
>  	ctx.offset = 3;
>  
>  	thread = g_thread_new("request-release",
> @@ -199,26 +209,20 @@ GPIOD_TEST_CASE(chip_fd_can_be_polled)
>  	g_autoptr(struct_gpiod_chip) chip = NULL;
>  	g_autoptr(struct_gpiod_line_info) info = NULL;
>  	g_autoptr(struct_gpiod_info_event) event = NULL;
> -	g_autoptr(struct_gpiod_line_config) line_cfg = NULL;
> -	g_autoptr(struct_gpiod_line_settings) settings = NULL;
>  	g_autoptr(GThread) thread = NULL;
> +	const char *chip_path = g_gpiosim_chip_get_dev_path(sim);
>  	struct gpiod_line_info *evinfo;
>  	struct request_ctx ctx;
>  	struct timespec ts;
>  	struct pollfd pfd;
>  	gint ret, fd;
>  
> -	chip = gpiod_test_open_chip_or_fail(g_gpiosim_chip_get_dev_path(sim));
> -	settings = gpiod_test_create_line_settings_or_fail();
> -	line_cfg = gpiod_test_create_line_config_or_fail();
> -
> +	chip = gpiod_test_open_chip_or_fail(chip_path);
>  	info = gpiod_test_chip_watch_line_info_or_fail(chip, 3);
>  
>  	g_assert_false(gpiod_line_info_is_used(info));
>  
> -	ctx.chip = chip;
> -	ctx.line_cfg = line_cfg;
> -	ctx.settings = settings;
> +	ctx.path = chip_path;
>  	ctx.offset = 3;
>  
>  	thread = g_thread_new("request-release",