[libcamera-devel] [PATCH v1 17/23] gst: Add a pool and an allocator implementation
Nicolas Dufresne
nicolas at ndufresne.ca
Tue Feb 25 21:15:17 CET 2020
Le mercredi 12 février 2020 à 02:16 +0200, Laurent Pinchart a écrit :
> Hi Nicolas,
>
> Thank you for the patch.
>
> On Tue, Jan 28, 2020 at 10:32:04PM -0500, Nicolas Dufresne wrote:
> > From: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> >
> > This is needed to track the livetime of the FrameBufferAllocator in relation to
>
> s/livetime/lifetime/
>
> > the GstBuffer/GstMemory objects travelling inside GStreamer.
> >
> > Signed-off-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> > ---
> > src/gstreamer/gstlibcameraallocator.cpp | 240 ++++++++++++++++++++++++
> > src/gstreamer/gstlibcameraallocator.h | 29 +++
> > src/gstreamer/gstlibcamerapool.cpp | 109 +++++++++++
> > src/gstreamer/gstlibcamerapool.h | 27 +++
> > src/gstreamer/meson.build | 11 +-
> > 5 files changed, 413 insertions(+), 3 deletions(-)
> > create mode 100644 src/gstreamer/gstlibcameraallocator.cpp
> > create mode 100644 src/gstreamer/gstlibcameraallocator.h
> > create mode 100644 src/gstreamer/gstlibcamerapool.cpp
> > create mode 100644 src/gstreamer/gstlibcamerapool.h
> >
> > diff --git a/src/gstreamer/gstlibcameraallocator.cpp b/src/gstreamer/gstlibcameraallocator.cpp
> > new file mode 100644
> > index 0000000..0f248b4
> > --- /dev/null
> > +++ b/src/gstreamer/gstlibcameraallocator.cpp
> > @@ -0,0 +1,240 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2020, Collabora Ltd.
> > + * Author: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> > + *
> > + * gstlibcameraallocator.cpp - GStreamer Custom Allocator
> > + */
> > +
> > +#include "gstlibcameraallocator.h"
> > +#include "gstlibcamera-utils.h"
> > +
> > +#include <libcamera/camera.h>
> > +#include <libcamera/stream.h>
> > +#include <libcamera/framebuffer_allocator.h>
>
> Could you please keep those headers alphabetically sorted ?
>
> > +
> > +using namespace libcamera;
> > +
> > +/***********************************************************************/
> > +/* Internal object for tracking memories associated with a FrameBuffer */
> > +/***********************************************************************/
>
> Same comment as before regarding this, a doxygen-style comment with a
> tiny bit of doc may be useful for inexperienced readers such as your
> devoted reviewer :-) You could combine the next comment with it.
>
> > +
> > +static gboolean gst_libcamera_allocator_release(GstMiniObject *mini_object);
>
> It would be nice to avoid forward declarations, but it may not be worth
> it.
It's always my goal, but this one was not avoidable.
>
> > +
> > +/* This internal object is used to track the outstanding GstMemory object that
>
> s/object/objects/
>
> > + * are part of a FrameBuffer. The allocator will only re-use a FrameBuffer when
> > + * al all outstranging GstMemory have returned.
>
> s/al all/all/ ?
> s/outstranging/outstanding/ ?
>
> > + */
> > +struct FrameWrap {
> > + FrameWrap(GstAllocator *allocator, FrameBuffer *buffer,
> > + gpointer stream);
> > + ~FrameWrap();
> > +
> > + void AcquirePlane() { ++outstanding_planes_; }
> > + bool ReleasePlane() { return --outstanding_planes_ == 0; }
>
> Methods should start with a lowercase letter (camelCase, not CamelCase
> as for type names).
>
> > +
> > + gpointer stream_;
> > + FrameBuffer *buffer_;
> > + std::vector<GstMemory *> planes_;
> > + gint outstanding_planes_;
>
> outstandingPlanes_ as it's a C++ class ?
>
> > +};
> > +
> > +static GQuark
> > +gst_libcamera_frame_quark(void)
>
> How about making this a static function of the FrameWrap class ?
>
> > +{
> > + static gsize frame_quark = 0;
> > +
> > + if (g_once_init_enter(&frame_quark)) {
> > + GQuark quark = g_quark_from_string("GstLibCameraFrameWrap");
> > + g_once_init_leave(&frame_quark, quark);
> > + }
> > +
> > + return frame_quark;
> > +}
> > +
> > +FrameWrap::FrameWrap(GstAllocator *allocator, FrameBuffer *buffer,
> > + gpointer stream)
> > +
> > + : stream_(stream),
> > + buffer_(buffer),
> > + outstanding_planes_(0)
> > +{
> > + for (const FrameBuffer::Plane &plane : buffer->planes()) {
> > + GstMemory *mem = gst_fd_allocator_alloc(allocator,
> > + plane.fd.fd(),
> > + plane.length,
> > + GST_FD_MEMORY_FLAG_DONT_CLOSE);
> > + gst_mini_object_set_qdata(GST_MINI_OBJECT(mem),
> > + gst_libcamera_frame_quark(),
> > + this, NULL);
> > + GST_MINI_OBJECT(mem)->dispose = gst_libcamera_allocator_release;
> > + g_object_unref(mem->allocator);
> > + planes_.push_back(mem);
> > + }
> > +}
> > +
> > +FrameWrap::~FrameWrap()
> > +{
> > + for (GstMemory *mem : planes_) {
> > + GST_MINI_OBJECT(mem)->dispose = nullptr;
> > + g_object_ref(mem->allocator);
> > + gst_memory_unref(mem);
> > + }
> > +}
> > +
> > +/***********************************/
> > +/* The GstAllocator implementation */
> > +/***********************************/
> > +struct _GstLibcameraAllocator {
> > + GstDmaBufAllocator parent;
> > + FrameBufferAllocator *fb_allocator;
> > + /* A hash table using Stream pointer as key and returning a GQueue of
> > + * FrameWrap. */
> > + GHashTable *pools;
> > +};
> > +
> > +G_DEFINE_TYPE(GstLibcameraAllocator, gst_libcamera_allocator,
> > + GST_TYPE_DMABUF_ALLOCATOR);
> > +
> > +static gboolean
> > +gst_libcamera_allocator_release(GstMiniObject *mini_object)
> > +{
> > + GstMemory *mem = GST_MEMORY_CAST(mini_object);
> > + GstLibcameraAllocator *self = GST_LIBCAMERA_ALLOCATOR(mem->allocator);
> > + GST_OBJECT_LOCKER(self);
> > + gpointer data = gst_mini_object_get_qdata(mini_object,
> > + gst_libcamera_frame_quark());
> > + auto *frame = (FrameWrap *)data;
>
> Could you use reinterpret_cast<FrameWrap *>(data) here ? And maybe
> replace auto with FrameWrap as it's short.
>
> In general, please use static_cast or reinterpret_cast as appropriate,
> as they offer more compile-time protection that C-style casts. I won't
> comment on other occurrences.
>
> > +
> > + gst_memory_ref(mem);
> > +
> > + if (frame->ReleasePlane()) {
> > + auto *pool = (GQueue *)g_hash_table_lookup(self->pools, frame->stream_);
> > + g_return_val_if_fail(pool, TRUE);
> > + g_queue_push_tail(pool, frame);
> > + }
> > +
> > + /* Keep last in case we are holding on the last allocator ref */
> > + g_object_unref(mem->allocator);
> > +
> > + /* Rreturns FALSE so that our mini object isn't freed */
>
> s/Rreturns/Return/
>
> > + return FALSE;
> > +}
> > +
> > +static void
> > +gst_libcamera_allocator_free_pool(gpointer data)
> > +{
> > + GQueue *queue = (GQueue *)data;
> > + FrameWrap *frame;
> > +
> > + while ((frame = (FrameWrap *)g_queue_pop_head(queue))) {
> > + g_warn_if_fail(frame->outstanding_planes_ == 0);
> > + delete frame;
> > + }
> > +
> > + g_queue_free(queue);
> > +}
> > +
> > +static void
> > +gst_libcamera_allocator_init(GstLibcameraAllocator *self)
> > +{
> > + self->pools = g_hash_table_new_full(NULL, NULL, NULL,
> > + gst_libcamera_allocator_free_pool);
> > + GST_OBJECT_FLAG_SET(self, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);
> > +}
> > +
> > +static void
> > +gst_libcamera_allocator_dispose(GObject *object)
> > +{
> > + GstLibcameraAllocator *self = GST_LIBCAMERA_ALLOCATOR(object);
> > +
> > + if (self->pools) {
> > + g_hash_table_unref(self->pools);
> > + self->pools = NULL;
> > + }
> > +
> > + G_OBJECT_CLASS(gst_libcamera_allocator_parent_class)->dispose(object);
> > +}
> > +
> > +static void
> > +gst_libcamera_allocator_finalize(GObject *object)
> > +{
> > + GstLibcameraAllocator *self = GST_LIBCAMERA_ALLOCATOR(object);
> > +
> > + delete self->fb_allocator;
> > +
> > + G_OBJECT_CLASS(gst_libcamera_allocator_parent_class)->finalize(object);
> > +}
> > +
> > +static void
> > +gst_libcamera_allocator_class_init(GstLibcameraAllocatorClass *klass)
> > +{
> > + auto *allocator_class = GST_ALLOCATOR_CLASS(klass);
> > + auto *object_class = G_OBJECT_CLASS(klass);
> > +
> > + object_class->dispose = gst_libcamera_allocator_dispose;
> > + object_class->finalize = gst_libcamera_allocator_finalize;
> > + allocator_class->alloc = NULL;
> > +}
> > +
> > +GstLibcameraAllocator *
> > +gst_libcamera_allocator_new(std::shared_ptr<Camera> camera)
> > +{
> > + auto *self = (GstLibcameraAllocator *)g_object_new(GST_TYPE_LIBCAMERA_ALLOCATOR,
> > + nullptr);
> > +
> > + self->fb_allocator = FrameBufferAllocator::create(camera);
> > + for (Stream *stream : camera->streams()) {
> > + gint ret;
> > +
> > + ret = self->fb_allocator->allocate(stream);
> > + if (ret == 0)
> > + return nullptr;
> > +
> > + GQueue *pool = g_queue_new();
> > + for (const std::unique_ptr<FrameBuffer> &buffer :
> > + self->fb_allocator->buffers(stream)) {
> > + auto *fb = new FrameWrap(GST_ALLOCATOR(self),
> > + buffer.get(), stream);
> > + g_queue_push_tail(pool, fb);
> > + }
> > +
> > + g_hash_table_insert(self->pools, stream, pool);
> > + }
> > +
> > + return self;
> > +}
> > +
> > +bool
> > +gst_libcamera_allocator_prepare_buffer(GstLibcameraAllocator *self,
> > + Stream *stream, GstBuffer *buffer)
> > +{
> > + GST_OBJECT_LOCKER(self);
> > +
> > + auto *pool = (GQueue *)g_hash_table_lookup(self->pools, stream);
> > + g_return_val_if_fail(pool, false);
> > +
> > + auto *frame = (FrameWrap *)g_queue_pop_head(pool);
> > + if (!frame)
> > + return false;
> > +
> > + for (GstMemory *mem : frame->planes_) {
> > + frame->AcquirePlane();
> > + gst_buffer_append_memory(buffer, mem);
> > + g_object_ref(mem->allocator);
> > + }
> > +
> > + return true;
> > +}
> > +
> > +gsize
> > +gst_libcamera_allocator_get_pool_size(GstLibcameraAllocator *self,
> > + Stream *stream)
> > +{
> > + GST_OBJECT_LOCKER(self);
> > +
> > + auto *pool = (GQueue *)g_hash_table_lookup(self->pools, stream);
> > + g_return_val_if_fail(pool, false);
> > +
> > + return pool->length;
> > +}
> > diff --git a/src/gstreamer/gstlibcameraallocator.h b/src/gstreamer/gstlibcameraallocator.h
> > new file mode 100644
> > index 0000000..f2a0f58
> > --- /dev/null
> > +++ b/src/gstreamer/gstlibcameraallocator.h
> > @@ -0,0 +1,29 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2020, Collabora Ltd.
> > + * Author: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> > + *
> > + * gstlibcameraallocator.h - GStreamer Custom Allocator
> > + */
> > +
> > +#include <gst/gst.h>
> > +#include <gst/allocators/allocators.h>
> > +#include <libcamera/stream.h>
> > +
> > +#ifndef __GST_LIBCAMERA_ALLOCATOR_H__
> > +#define __GST_LIBCAMERA_ALLOCATOR_H__
> > +
> > +#define GST_TYPE_LIBCAMERA_ALLOCATOR gst_libcamera_allocator_get_type()
> > +G_DECLARE_FINAL_TYPE(GstLibcameraAllocator, gst_libcamera_allocator,
> > + GST_LIBCAMERA, ALLOCATOR, GstDmaBufAllocator)
> > +
> > +GstLibcameraAllocator *gst_libcamera_allocator_new(std::shared_ptr<libcamera::Camera> camera);
> > +
> > +bool gst_libcamera_allocator_prepare_buffer(GstLibcameraAllocator *self,
> > + libcamera::Stream *stream,
> > + GstBuffer *buffer);
> > +
> > +gsize gst_libcamera_allocator_get_pool_size(GstLibcameraAllocator *allocator,
> > + libcamera::Stream *stream);
> > +
> > +#endif /* __GST_LIBCAMERA_ALLOCATOR_H__ */
> > diff --git a/src/gstreamer/gstlibcamerapool.cpp b/src/gstreamer/gstlibcamerapool.cpp
> > new file mode 100644
> > index 0000000..f84d1d6
> > --- /dev/null
> > +++ b/src/gstreamer/gstlibcamerapool.cpp
> > @@ -0,0 +1,109 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2020, Collabora Ltd.
> > + * Author: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> > + *
> > + * gstlibcamerapool.cpp - GStreamer Buffer Pool
> > + */
> > +
> > +#include "gstlibcamerapool.h"
> > +#include "gstlibcamera-utils.h"
> > +
> > +#include <libcamera/stream.h>
> > +
> > +using namespace libcamera;
> > +
> > +struct _GstLibcameraPool {
> > + GstBufferPool parent;
> > +
> > + GstAtomicQueue *queue;
> > + GstLibcameraAllocator *allocator;
> > + Stream *stream;
> > +};
> > +
> > +G_DEFINE_TYPE(GstLibcameraPool, gst_libcamera_pool, GST_TYPE_BUFFER_POOL);
> > +
> > +static GstFlowReturn
> > +gst_libcamera_pool_acquire_buffer(GstBufferPool *pool, GstBuffer **buffer,
> > + GstBufferPoolAcquireParams *params)
> > +{
> > + GstLibcameraPool *self = GST_LIBCAMERA_POOL(pool);
> > + GstBuffer *buf = (GstBuffer *)gst_atomic_queue_pop(self->queue);
> > + if (!buf)
> > + return GST_FLOW_ERROR;
> > +
> > + if (!gst_libcamera_allocator_prepare_buffer(self->allocator, self->stream, buf))
> > + return GST_FLOW_ERROR;
> > +
> > + *buffer = buf;
> > + return GST_FLOW_OK;
> > +}
> > +
> > +static void
> > +gst_libcamera_pool_reset_buffer(GstBufferPool *pool, GstBuffer *buffer)
> > +{
> > + GstBufferPoolClass *klass = GST_BUFFER_POOL_CLASS(gst_libcamera_pool_parent_class);
> > +
> > + /* Clears all the memories and only pool the GstBuffer objects */
> > + gst_buffer_remove_all_memory(buffer);
> > + klass->reset_buffer(pool, buffer);
> > + GST_BUFFER_FLAGS(buffer) = 0;
> > +}
> > +
> > +static void
> > +gst_libcamera_pool_release_buffer(GstBufferPool *pool, GstBuffer *buffer)
> > +{
> > + GstLibcameraPool *self = GST_LIBCAMERA_POOL(pool);
> > + gst_atomic_queue_push(self->queue, (gpointer)buffer);
> > +}
> > +
> > +static void
> > +gst_libcamera_pool_init(GstLibcameraPool *self)
> > +{
> > + self->queue = gst_atomic_queue_new(4);
> > +}
> > +
> > +static void
> > +gst_libcamera_pool_finalize(GObject *object)
> > +{
> > + GstLibcameraPool *self = GST_LIBCAMERA_POOL(object);
> > + GstBuffer *buf;
> > +
> > + while ((buf = (GstBuffer *)gst_atomic_queue_pop(self->queue)))
> > + gst_buffer_unref(buf);
> > +
> > + gst_atomic_queue_unref(self->queue);
> > + g_object_unref(self->allocator);
> > +
> > + G_OBJECT_CLASS(gst_libcamera_pool_parent_class)->finalize(object);
> > +}
> > +
> > +static void
> > +gst_libcamera_pool_class_init(GstLibcameraPoolClass *klass)
> > +{
> > + auto *object_class = G_OBJECT_CLASS(klass);
> > + auto *pool_class = GST_BUFFER_POOL_CLASS(klass);
> > +
> > + object_class->finalize = gst_libcamera_pool_finalize;
> > + pool_class->start = nullptr;
> > + pool_class->acquire_buffer = gst_libcamera_pool_acquire_buffer;
> > + pool_class->reset_buffer = gst_libcamera_pool_reset_buffer;
> > + pool_class->release_buffer = gst_libcamera_pool_release_buffer;
> > +}
> > +
> > +GstLibcameraPool *
> > +gst_libcamera_pool_new(GstLibcameraAllocator *allocator, Stream *stream)
> > +{
> > + auto *pool = (GstLibcameraPool *)g_object_new(GST_TYPE_LIBCAMERA_POOL, nullptr);
> > +
> > + pool->allocator = (GstLibcameraAllocator *)g_object_ref(allocator);
> > + pool->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);
> > + }
> > +
> > + return pool;
> > +}
> > diff --git a/src/gstreamer/gstlibcamerapool.h b/src/gstreamer/gstlibcamerapool.h
> > new file mode 100644
> > index 0000000..ca6b299
> > --- /dev/null
> > +++ b/src/gstreamer/gstlibcamerapool.h
> > @@ -0,0 +1,27 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2020, Collabora Ltd.
> > + * Author: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> > + *
> > + * gstlibcamerapool.h - GStreamer Buffer Pool
> > + *
> > + * This is a partial implementation of GstBufferPool intended for internal use
> > + * only. This pool cannot be configured or activated.
> > + */
> > +
> > +#include <gst/gst.h>
> > +#include <libcamera/stream.h>
> > +
> > +#include "gstlibcameraallocator.h"
> > +
> > +#ifndef __GST_LIBCAMERA_POOL_H__
> > +#define __GST_LIBCAMERA_POOL_H__
> > +
> > +#define GST_TYPE_LIBCAMERA_POOL gst_libcamera_pool_get_type()
> > +G_DECLARE_FINAL_TYPE(GstLibcameraPool, gst_libcamera_pool,
> > + GST_LIBCAMERA, POOL, GstBufferPool)
> > +
> > +GstLibcameraPool *gst_libcamera_pool_new(GstLibcameraAllocator *allocator,
> > + libcamera::Stream *stream);
> > +
> > +#endif /* __GST_LIBCAMERA_POOL_H__ */
> > diff --git a/src/gstreamer/meson.build b/src/gstreamer/meson.build
> > index e497bf4..346910f 100644
> > --- a/src/gstreamer/meson.build
> > +++ b/src/gstreamer/meson.build
> > @@ -4,6 +4,8 @@ libcamera_gst_sources = [
> > 'gstlibcamerasrc.cpp',
> > 'gstlibcameraprovider.cpp',
> > 'gstlibcamerapad.cpp',
> > + 'gstlibcameraallocator.cpp',
> > + 'gstlibcamerapool.cpp'
> > ]
> >
> > libcamera_gst_c_args = [
> > @@ -11,15 +13,18 @@ libcamera_gst_c_args = [
> > '-DPACKAGE="@0@"'.format(meson.project_name()),
> > ]
> >
> > -gst_dep = dependency('gstreamer-video-1.0', version : '>=1.16.1',
> > +gst_req = '>=1.16.1'
>
> Maybe gst_dep_version instead of gst_req ?
>
> > +gstvideo_dep = dependency('gstreamer-video-1.0', version : gst_req,
> > + required : get_option('gstreamer'))
> > +gstallocator_dep = dependency('gstreamer-allocators-1.0', version : gst_req,
> > required : get_option('gstreamer'))
> >
> > -if gst_dep.found()
> > +if gstvideo_dep.found() and gstallocator_dep.found()
> > libcamera_gst = shared_library('gstlibcamera',
> > libcamera_gst_sources,
> > c_args : libcamera_gst_c_args,
> > include_directories : [],
> > - dependencies : [libcamera_dep, gst_dep],
> > + dependencies : [libcamera_dep, gstvideo_dep, gstallocator_dep],
> > install: true,
> > install_dir : '@0@/gstreamer-1.0'.format(get_option('libdir')),
> > )
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