[PATCH v2 3/3] test: gstreamer: Test memory lifetime

[Kieran Bingham]

Quoting Nicolas Dufresne (2024-03-05 15:30:58)
> From: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> 
> Test that everything works fine if a buffer outlives the pipeline.
> 
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> ---
>  .../gstreamer_memory_lifetime_test.cpp        | 75 +++++++++++++++++++
>  test/gstreamer/meson.build                    |  4 +-
>  2 files changed, 78 insertions(+), 1 deletion(-)
>  create mode 100644 test/gstreamer/gstreamer_memory_lifetime_test.cpp
> 
> diff --git a/test/gstreamer/gstreamer_memory_lifetime_test.cpp b/test/gstreamer/gstreamer_memory_lifetime_test.cpp
> new file mode 100644
> index 00000000..6d932e9e
> --- /dev/null
> +++ b/test/gstreamer/gstreamer_memory_lifetime_test.cpp
> @@ -0,0 +1,75 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2024, Nicolas Dufresne
> + *
> + * gstreamer_memory_lifetime_test.cpp - GStreamer memory lifetime test
> + */
> +
> +#include <iostream>
> +#include <unistd.h>
> +
> +#include <gst/app/app.h>
> +#include <gst/gst.h>
> +
> +#include "gstreamer_test.h"
> +#include "test.h"
> +
> +using namespace std;
> +
> +class GstreamerMemoryLifetimeTest : public GstreamerTest, public Test
> +{
> +public:
> +       GstreamerMemoryLifetimeTest()
> +               : GstreamerTest()
> +       {
> +       }
> +
> +protected:
> +       int init() override
> +       {
> +               if (status_ != TestPass)
> +                       return status_;
> +
> +               appsink_ = gst_element_factory_make("appsink", nullptr);
> +               if (!appsink_) {
> +                       g_printerr("Your installation is missing 'appsink'\n");
> +                       return TestFail;
> +               }
> +               g_object_ref_sink(appsink_);
> +
> +               return createPipeline();
> +       }
> +
> +       int run() override
> +       {
> +               /* Build the pipeline */
> +               gst_bin_add_many(GST_BIN(pipeline_), libcameraSrc_, appsink_, nullptr);
> +               if (gst_element_link(libcameraSrc_, appsink_) != TRUE) {
> +                       g_printerr("Elements could not be linked.\n");
> +                       return TestFail;
> +               }
> +
> +               if (startPipeline() != TestPass)
> +                       return TestFail;
> +
> +               sample_ = gst_app_sink_try_pull_sample(GST_APP_SINK(appsink_), GST_SECOND * 5);
> +               gst_element_set_state(pipeline_, GST_STATE_NULL);
> +
> +               if (!sample_)
> +                       return TestFail;

Is this the part that does the test? I don't really know how this test
is working.

Is it pulling a single buffer? Does set_state(GST_STATE_NULL) destroy
the pipeline?

Any comments we can add here to make it clearer what is actually being
tested or happening? The code doesn't really tell me what's going on
under the hood.

Does the test for !sample_ really mean the buffer still exists and is
valid? Does the test need to do anything to /access/ the buffer to make
sure the test proves it succeeded?

I expect it probably does as otherwise you'd have added more - but it's
just not obvious from the above.



> +
> +               return TestPass;
> +       }
> +
> +       void cleanup() override
> +       {
> +               g_clear_pointer(&sample_, gst_sample_unref);
> +               g_clear_object(&appsink_);
> +       }
> +
> +private:
> +       GstElement *appsink_;
> +       GstSample *sample_;
> +};
> +
> +TEST_REGISTER(GstreamerMemoryLifetimeTest)
> diff --git a/test/gstreamer/meson.build b/test/gstreamer/meson.build
> index f3ba5a23..70609b88 100644
> --- a/test/gstreamer/meson.build
> +++ b/test/gstreamer/meson.build
> @@ -8,12 +8,14 @@ gstreamer_tests = [
>      {'name': 'single_stream_test', 'sources': ['gstreamer_single_stream_test.cpp']},
>      {'name': 'multi_stream_test', 'sources': ['gstreamer_multi_stream_test.cpp']},
>      {'name': 'device_provider_test', 'sources': ['gstreamer_device_provider_test.cpp']},
> +    {'name': 'memory_lifetime_test', 'sources': ['gstreamer_memory_lifetime_test.cpp']},
>  ]
>  gstreamer_dep = dependency('gstreamer-1.0', required : true)
> +gstapp_dep = dependency('gstreamer-app-1.0', required : true)
>  
>  foreach test : gstreamer_tests
>      exe = executable(test['name'], test['sources'], 'gstreamer_test.cpp',
> -                     dependencies : [libcamera_private, gstreamer_dep],
> +                     dependencies : [libcamera_private, gstreamer_dep, gstapp_dep],
>                       link_with : test_libraries,
>                       include_directories : test_includes_internal)
>  
> -- 
> 2.43.2
>