[libcamera-devel] [PATCH v4 02/15] py: New event handling
Tomi Valkeinen
tomi.valkeinen at ideasonboard.com
Thu Mar 9 15:25:48 CET 2023
At the moment the Python bindings only handle the requestCompleted
events. But we have others, bufferCompleted and disconnect from the
Camera, and cameraAdded and cameraRemoved from the CameraManager.
This patch makes all those events available to the users.
The get_ready_requests() method is now deprecated, but available to keep
backward compatibility.
The new event handling works like get_ready_requests(), but instead of
returning only Requests from requestCompleted events, it returns all
event types using a new Event class.
Additionally camera.stop() has been changed to return events for that
camera. This serves two purposes: first, it removes the requestCompleted
events from the event queue, thus preventing the old events being
returned when the camera is started again, and second, it allows the
user to process those events if it so wants.
All other event types are always collected and returned, except
bufferCompleted which needs to be enabled by setting the
CameraManager.buffer_completed_active to True. This is to reduce the
overhead a bit. It is not clear if this is a necessary optimization or
not.
TODO: Documentation.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
---
src/py/libcamera/py_camera_manager.cpp | 195 +++++++++++++++++++++++--
src/py/libcamera/py_camera_manager.h | 66 ++++++++-
src/py/libcamera/py_main.cpp | 44 +++++-
3 files changed, 281 insertions(+), 24 deletions(-)
diff --git a/src/py/libcamera/py_camera_manager.cpp b/src/py/libcamera/py_camera_manager.cpp
index 9ccb7aad..7d6dded4 100644
--- a/src/py/libcamera/py_camera_manager.cpp
+++ b/src/py/libcamera/py_camera_manager.cpp
@@ -5,6 +5,7 @@
#include "py_camera_manager.h"
+#include <algorithm>
#include <errno.h>
#include <memory>
#include <sys/eventfd.h>
@@ -35,11 +36,17 @@ PyCameraManager::PyCameraManager()
if (ret)
throw std::system_error(-ret, std::generic_category(),
"Failed to start CameraManager");
+
+ cameraManager_->cameraAdded.connect(this, &PyCameraManager::handleCameraAdded);
+ cameraManager_->cameraRemoved.connect(this, &PyCameraManager::handleCameraRemoved);
}
PyCameraManager::~PyCameraManager()
{
LOG(Python, Debug) << "~PyCameraManager()";
+
+ cameraManager_->cameraAdded.disconnect();
+ cameraManager_->cameraRemoved.disconnect();
}
py::list PyCameraManager::cameras()
@@ -60,6 +67,43 @@ py::list PyCameraManager::cameras()
return l;
}
+PyCameraEvent PyCameraManager::convertEvent(const CameraEvent &event)
+{
+ /*
+ * We need to set a keep-alive here so that the camera keeps the
+ * camera manager alive.
+ */
+ py::object py_cm = py::cast(this);
+ py::object py_cam = py::cast(event.camera_);
+ py::detail::keep_alive_impl(py_cam, py_cm);
+
+ PyCameraEvent pyevent(event.type_, py_cam);
+
+ switch (event.type_) {
+ case CameraEventType::CameraAdded:
+ case CameraEventType::CameraRemoved:
+ case CameraEventType::Disconnect:
+ /* No additional parameters to add */
+ break;
+
+ case CameraEventType::BufferCompleted:
+ pyevent.request_ = py::cast(event.request_);
+ pyevent.fb_ = py::cast(event.fb_);
+ break;
+
+ case CameraEventType::RequestCompleted:
+ pyevent.request_ = py::cast(event.request_);
+
+ /* Decrease the ref increased in Camera.queue_request() */
+ pyevent.request_.dec_ref();
+
+ break;
+ }
+
+ return pyevent;
+}
+
+/* DEPRECATED */
std::vector<py::object> PyCameraManager::getReadyRequests()
{
int ret = readFd();
@@ -72,21 +116,134 @@ std::vector<py::object> PyCameraManager::getReadyRequests()
std::vector<py::object> py_reqs;
- for (Request *request : getCompletedRequests()) {
- py::object o = py::cast(request);
- /* Decrease the ref increased in Camera.queue_request() */
- o.dec_ref();
- py_reqs.push_back(o);
+ for (const auto &ev : getEvents()) {
+ if (ev.type_ != CameraEventType::RequestCompleted)
+ continue;
+
+ PyCameraEvent pyev = convertEvent(ev);
+ py_reqs.push_back(pyev.request_);
}
return py_reqs;
}
+std::vector<PyCameraEvent> PyCameraManager::getPyEvents()
+{
+ int ret = readFd();
+
+ if (ret == EAGAIN) {
+ LOG(Python, Debug) << "No events";
+ return {};
+ }
+
+ if (ret != 0)
+ throw std::system_error(ret, std::generic_category());
+
+ std::vector<CameraEvent> events = getEvents();
+
+ LOG(Python, Debug) << "Got " << events.size() << " events";
+
+ std::vector<PyCameraEvent> pyevents;
+ pyevents.reserve(events.size());
+
+ std::transform(events.begin(), events.end(), std::back_inserter(pyevents),
+ [this](const CameraEvent &ev) {
+ return convertEvent(ev);
+ });
+
+ return pyevents;
+}
+
+static bool isCameraSpecificEvent(const CameraEvent &event, std::shared_ptr<Camera> &camera)
+{
+ return event.camera_ == camera &&
+ (event.type_ == CameraEventType::RequestCompleted ||
+ event.type_ == CameraEventType::BufferCompleted ||
+ event.type_ == CameraEventType::Disconnect);
+}
+
+std::vector<PyCameraEvent> PyCameraManager::getPyCameraEvents(std::shared_ptr<Camera> camera)
+{
+ std::vector<CameraEvent> events;
+ size_t unhandled_size;
+
+ {
+ MutexLocker guard(eventsMutex_);
+
+ /*
+ * Collect events related to the given camera and remove them
+ * from the events_ vector.
+ */
+
+ auto it = events_.begin();
+ while (it != events_.end()) {
+ if (isCameraSpecificEvent(*it, camera)) {
+ events.push_back(*it);
+ it = events_.erase(it);
+ } else {
+ it++;
+ }
+ }
+
+ unhandled_size = events_.size();
+ }
+
+ /* Convert events to Python events */
+
+ std::vector<PyCameraEvent> pyevents;
+
+ for (const auto &event : events) {
+ PyCameraEvent pyev = convertEvent(event);
+ pyevents.push_back(pyev);
+ }
+
+ LOG(Python, Debug) << "Got " << pyevents.size() << " camera events, "
+ << unhandled_size << " unhandled events left";
+
+ return pyevents;
+}
+
/* Note: Called from another thread */
-void PyCameraManager::handleRequestCompleted(Request *req)
+void PyCameraManager::handleBufferCompleted(std::shared_ptr<Camera> cam, Request *req, FrameBuffer *fb)
{
- pushRequest(req);
- writeFd();
+ if (!bufferCompletedEventActive_)
+ return;
+
+ CameraEvent ev(CameraEventType::BufferCompleted, cam, req, fb);
+
+ pushEvent(ev);
+}
+
+/* Note: Called from another thread */
+void PyCameraManager::handleRequestCompleted(std::shared_ptr<Camera> cam, Request *req)
+{
+ CameraEvent ev(CameraEventType::RequestCompleted, cam, req);
+
+ pushEvent(ev);
+}
+
+/* Note: Called from another thread */
+void PyCameraManager::handleDisconnected(std::shared_ptr<Camera> cam)
+{
+ CameraEvent ev(CameraEventType::Disconnect, cam);
+
+ pushEvent(ev);
+}
+
+/* Note: Called from another thread */
+void PyCameraManager::handleCameraAdded(std::shared_ptr<Camera> cam)
+{
+ CameraEvent ev(CameraEventType::CameraAdded, cam);
+
+ pushEvent(ev);
+}
+
+/* Note: Called from another thread */
+void PyCameraManager::handleCameraRemoved(std::shared_ptr<Camera> cam)
+{
+ CameraEvent ev(CameraEventType::CameraRemoved, cam);
+
+ pushEvent(ev);
}
void PyCameraManager::writeFd()
@@ -116,16 +273,24 @@ int PyCameraManager::readFd()
return -EIO;
}
-void PyCameraManager::pushRequest(Request *req)
+void PyCameraManager::pushEvent(const CameraEvent &ev)
{
- MutexLocker guard(completedRequestsMutex_);
- completedRequests_.push_back(req);
+ {
+ MutexLocker guard(eventsMutex_);
+ events_.push_back(ev);
+ }
+
+ writeFd();
+
+ LOG(Python, Debug) << "Queued events: " << events_.size();
}
-std::vector<Request *> PyCameraManager::getCompletedRequests()
+std::vector<CameraEvent> PyCameraManager::getEvents()
{
- std::vector<Request *> v;
- MutexLocker guard(completedRequestsMutex_);
- swap(v, completedRequests_);
+ std::vector<CameraEvent> v;
+
+ MutexLocker guard(eventsMutex_);
+ swap(v, events_);
+
return v;
}
diff --git a/src/py/libcamera/py_camera_manager.h b/src/py/libcamera/py_camera_manager.h
index 3525057d..757f6d8e 100644
--- a/src/py/libcamera/py_camera_manager.h
+++ b/src/py/libcamera/py_camera_manager.h
@@ -13,6 +13,48 @@
using namespace libcamera;
+enum class CameraEventType {
+ CameraAdded,
+ CameraRemoved,
+ Disconnect,
+ RequestCompleted,
+ BufferCompleted,
+};
+
+/*
+ * This event struct is used internally to queue the events we receive from
+ * other threads.
+ */
+struct CameraEvent {
+ CameraEvent(CameraEventType type, std::shared_ptr<Camera> camera,
+ Request *request = nullptr, FrameBuffer *fb = nullptr)
+ : type_(type), camera_(camera), request_(request), fb_(fb)
+ {
+ }
+
+ CameraEventType type_;
+ std::shared_ptr<Camera> camera_;
+ Request *request_;
+ FrameBuffer *fb_;
+};
+
+/*
+ * This event struct is passed to Python. We need to use pybind11::object here
+ * instead of a C++ pointer so that we keep a ref to the Request, and a
+ * keep-alive from the camera to the camera manager.
+ */
+struct PyCameraEvent {
+ PyCameraEvent(CameraEventType type, pybind11::object camera)
+ : type_(type), camera_(camera)
+ {
+ }
+
+ CameraEventType type_;
+ pybind11::object camera_;
+ pybind11::object request_;
+ pybind11::object fb_;
+};
+
class PyCameraManager
{
public:
@@ -26,20 +68,30 @@ public:
int eventFd() const { return eventFd_.get(); }
- std::vector<pybind11::object> getReadyRequests();
+ std::vector<pybind11::object> getReadyRequests(); /* DEPRECATED */
+ std::vector<PyCameraEvent> getPyEvents();
+ std::vector<PyCameraEvent> getPyCameraEvents(std::shared_ptr<Camera> camera);
+
+ void handleBufferCompleted(std::shared_ptr<Camera> cam, Request *req, FrameBuffer *fb);
+ void handleRequestCompleted(std::shared_ptr<Camera> cam, Request *req);
+ void handleDisconnected(std::shared_ptr<Camera> cam);
+ void handleCameraAdded(std::shared_ptr<Camera> cam);
+ void handleCameraRemoved(std::shared_ptr<Camera> cam);
- void handleRequestCompleted(Request *req);
+ bool bufferCompletedEventActive_ = false;
private:
std::unique_ptr<CameraManager> cameraManager_;
UniqueFD eventFd_;
- libcamera::Mutex completedRequestsMutex_;
- std::vector<Request *> completedRequests_
- LIBCAMERA_TSA_GUARDED_BY(completedRequestsMutex_);
+ libcamera::Mutex eventsMutex_;
+ std::vector<CameraEvent> events_
+ LIBCAMERA_TSA_GUARDED_BY(eventsMutex_);
void writeFd();
int readFd();
- void pushRequest(Request *req);
- std::vector<Request *> getCompletedRequests();
+ void pushEvent(const CameraEvent &ev);
+ std::vector<CameraEvent> getEvents();
+
+ PyCameraEvent convertEvent(const CameraEvent &event);
};
diff --git a/src/py/libcamera/py_main.cpp b/src/py/libcamera/py_main.cpp
index 1d4c23b3..0fffc030 100644
--- a/src/py/libcamera/py_main.cpp
+++ b/src/py/libcamera/py_main.cpp
@@ -61,6 +61,7 @@ PYBIND11_MODULE(_libcamera, m)
* https://pybind11.readthedocs.io/en/latest/advanced/misc.html#avoiding-c-types-in-docstrings
*/
+ auto pyEvent = py::class_<PyCameraEvent>(m, "Event");
auto pyCameraManager = py::class_<PyCameraManager>(m, "CameraManager");
auto pyCamera = py::class_<Camera>(m, "Camera");
auto pyCameraConfiguration = py::class_<CameraConfiguration>(m, "CameraConfiguration");
@@ -93,6 +94,20 @@ PYBIND11_MODULE(_libcamera, m)
m.def("log_set_level", &logSetLevel);
/* Classes */
+
+ py::enum_<CameraEventType>(pyEvent, "Type")
+ .value("CameraAdded", CameraEventType::CameraAdded)
+ .value("CameraRemoved", CameraEventType::CameraRemoved)
+ .value("Disconnect", CameraEventType::Disconnect)
+ .value("RequestCompleted", CameraEventType::RequestCompleted)
+ .value("BufferCompleted", CameraEventType::BufferCompleted);
+
+ pyEvent
+ .def_readonly("type", &PyCameraEvent::type_)
+ .def_readonly("camera", &PyCameraEvent::camera_)
+ .def_readonly("request", &PyCameraEvent::request_)
+ .def_readonly("fb", &PyCameraEvent::fb_);
+
pyCameraManager
.def_static("singleton", []() {
std::shared_ptr<PyCameraManager> cm = gCameraManager.lock();
@@ -110,7 +125,13 @@ PYBIND11_MODULE(_libcamera, m)
.def_property_readonly("cameras", &PyCameraManager::cameras)
.def_property_readonly("event_fd", &PyCameraManager::eventFd)
- .def("get_ready_requests", &PyCameraManager::getReadyRequests);
+
+ /* DEPRECATED */
+ .def("get_ready_requests", &PyCameraManager::getReadyRequests)
+
+ .def("get_events", &PyCameraManager::getPyEvents)
+
+ .def_readwrite("buffer_completed_active", &PyCameraManager::bufferCompletedEventActive_);
pyCamera
.def_property_readonly("id", &Camera::id)
@@ -133,7 +154,17 @@ PYBIND11_MODULE(_libcamera, m)
auto cm = gCameraManager.lock();
ASSERT(cm);
- self.requestCompleted.connect(cm.get(), &PyCameraManager::handleRequestCompleted);
+ self.requestCompleted.connect(&self, [cm, camera=self.shared_from_this()](Request *req) {
+ cm->handleRequestCompleted(camera, req);
+ });
+
+ self.bufferCompleted.connect(&self, [cm, camera=self.shared_from_this()](Request *req, FrameBuffer *fb) {
+ cm->handleBufferCompleted(camera, req, fb);
+ });
+
+ self.disconnected.connect(&self, [cm, camera=self.shared_from_this()]() {
+ cm->handleDisconnected(camera);
+ });
ControlList controlList(self.controls());
@@ -154,10 +185,19 @@ PYBIND11_MODULE(_libcamera, m)
int ret = self.stop();
self.requestCompleted.disconnect();
+ self.bufferCompleted.disconnect();
+ self.disconnected.disconnect();
+
+ auto cm = gCameraManager.lock();
+ ASSERT(cm);
+
+ auto events = cm->getPyCameraEvents(self.shared_from_this());
if (ret)
throw std::system_error(-ret, std::generic_category(),
"Failed to stop camera");
+
+ return events;
})
.def("__str__", [](Camera &self) {
--
2.34.1
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