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authorNicolas Dufresne <nicolas.dufresne@collabora.com>2024-06-05 15:41:20 -0400
committerKieran Bingham <kieran.bingham@ideasonboard.com>2024-07-25 09:54:56 +0100
commit04f1f2033724f038ab1152e8135292770a33f97a (patch)
tree81ddfe145cdc3cf1c4d4d346d5bd37e388489186 /src
parent01132257b9e70e6408e98e7df684c6db3aefe8e8 (diff)
gstreamer: pool: Replace GstAtomicQueue with deque and mutex
The GstAtomicQueue only supports 2 threads, one pushing, and one popping. We pop and push on error cases and we may have multiple threads downstream returning buffer (using tee), which breaks this assumption. On top of which, the release function, that notifies when the queue goes from empty to not-empty relies on a racy empty check. The downstream thread that does this check is effectively concurrent with our thread calling acquire(). Fix this by replacing the GstAtomicQueue with a std::deque, and protect access to that using the object lock. Bug: https://bugs.libcamera.org/show_bug.cgi?id=201 Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Diffstat (limited to 'src')
-rw-r--r--src/gstreamer/gstlibcamerapool.cpp40
1 files changed, 31 insertions, 9 deletions
diff --git a/src/gstreamer/gstlibcamerapool.cpp b/src/gstreamer/gstlibcamerapool.cpp
index 9661c67a..0b1a5689 100644
--- a/src/gstreamer/gstlibcamerapool.cpp
+++ b/src/gstreamer/gstlibcamerapool.cpp
@@ -8,6 +8,7 @@
#include "gstlibcamerapool.h"
+#include <deque>
#include <libcamera/stream.h>
#include "gstlibcamera-utils.h"
@@ -24,24 +25,41 @@ static guint signals[N_SIGNALS];
struct _GstLibcameraPool {
GstBufferPool parent;
- GstAtomicQueue *queue;
+ std::deque<GstBuffer *> *queue;
GstLibcameraAllocator *allocator;
Stream *stream;
};
G_DEFINE_TYPE(GstLibcameraPool, gst_libcamera_pool, GST_TYPE_BUFFER_POOL)
+static GstBuffer *
+gst_libcamera_pool_pop_buffer(GstLibcameraPool *self)
+{
+ GLibLocker lock(GST_OBJECT(self));
+ GstBuffer *buf;
+
+ if (self->queue->empty())
+ return nullptr;
+
+ buf = self->queue->front();
+ self->queue->pop_front();
+
+ return buf;
+}
+
static GstFlowReturn
gst_libcamera_pool_acquire_buffer(GstBufferPool *pool, GstBuffer **buffer,
[[maybe_unused]] GstBufferPoolAcquireParams *params)
{
GstLibcameraPool *self = GST_LIBCAMERA_POOL(pool);
- GstBuffer *buf = GST_BUFFER(gst_atomic_queue_pop(self->queue));
+ GstBuffer *buf = gst_libcamera_pool_pop_buffer(self);
+
if (!buf)
return GST_FLOW_ERROR;
if (!gst_libcamera_allocator_prepare_buffer(self->allocator, self->stream, buf)) {
- gst_atomic_queue_push(self->queue, buf);
+ GLibLocker lock(GST_OBJECT(self));
+ self->queue->push_back(buf);
return GST_FLOW_ERROR;
}
@@ -64,9 +82,13 @@ static void
gst_libcamera_pool_release_buffer(GstBufferPool *pool, GstBuffer *buffer)
{
GstLibcameraPool *self = GST_LIBCAMERA_POOL(pool);
- bool do_notify = gst_atomic_queue_length(self->queue) == 0;
+ bool do_notify;
- gst_atomic_queue_push(self->queue, buffer);
+ {
+ GLibLocker lock(GST_OBJECT(self));
+ do_notify = self->queue->empty();
+ self->queue->push_back(buffer);
+ }
if (do_notify)
g_signal_emit(self, signals[SIGNAL_BUFFER_NOTIFY], 0);
@@ -75,7 +97,7 @@ gst_libcamera_pool_release_buffer(GstBufferPool *pool, GstBuffer *buffer)
static void
gst_libcamera_pool_init(GstLibcameraPool *self)
{
- self->queue = gst_atomic_queue_new(4);
+ self->queue = new std::deque<GstBuffer *>();
}
static void
@@ -84,10 +106,10 @@ gst_libcamera_pool_finalize(GObject *object)
GstLibcameraPool *self = GST_LIBCAMERA_POOL(object);
GstBuffer *buf;
- while ((buf = GST_BUFFER(gst_atomic_queue_pop(self->queue))))
+ while ((buf = gst_libcamera_pool_pop_buffer(self)))
gst_buffer_unref(buf);
- gst_atomic_queue_unref(self->queue);
+ delete self->queue;
g_object_unref(self->allocator);
G_OBJECT_CLASS(gst_libcamera_pool_parent_class)->finalize(object);
@@ -122,7 +144,7 @@ gst_libcamera_pool_new(GstLibcameraAllocator *allocator, Stream *stream)
gsize pool_size = gst_libcamera_allocator_get_pool_size(allocator, stream);
for (gsize i = 0; i < pool_size; i++) {
GstBuffer *buffer = gst_buffer_new();
- gst_atomic_queue_push(pool->queue, buffer);
+ pool->queue->push_back(buffer);
}
return pool;