[libcamera-devel] [PATCH v5 03/13] py: New event handling
Tomi Valkeinen
tomi.valkeinen at ideasonboard.com
Sat Jun 3 09:56:05 CEST 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
specific camera. This serves two purposes: first, it removes the
RequestCompleted and BufferCompleted 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.
The CameraManager events (CameraAdded and CameraRemoved) are always
enabled, but of the Camera events only RequestCompleted is enabled by
default. Other Camera events can be enabled
Camera.enable_camera_event().
Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
---
Documentation/python-bindings.rst | 24 ++-
src/py/libcamera/py_camera_manager.cpp | 275 +++++++++++++++++++++++--
src/py/libcamera/py_camera_manager.h | 73 ++++++-
src/py/libcamera/py_main.cpp | 54 ++++-
4 files changed, 386 insertions(+), 40 deletions(-)
diff --git a/Documentation/python-bindings.rst b/Documentation/python-bindings.rst
index bac5cd34..8f2d76c3 100644
--- a/Documentation/python-bindings.rst
+++ b/Documentation/python-bindings.rst
@@ -43,17 +43,23 @@ CameraManager
The Python API provides a singleton CameraManager via ``CameraManager.singleton()``.
There is no need to start or stop the CameraManager.
-Handling Completed Requests
----------------------------
+Event Handling
+--------------
-The Python bindings do not expose the ``Camera::requestCompleted`` signal
-directly as the signal is invoked from another thread and it has real-time
-constraints. Instead the bindings queue the completed requests internally and
-use an eventfd to inform the user that there are completed requests.
+The Python bindings do not expose the signals from the C++ side directly as the
+signals are invoked from another thread and they may have real-time
+constraints. Instead the bindings queue the received events internally and use
+an eventfd to inform the user that there are events to be handled.
-The user can wait on the eventfd, and upon getting an event, use
-``CameraManager.get_ready_requests()`` to clear the eventfd event and to get
-the completed requests.
+The user can wait on the eventfd (e.g. by using Python Selector), and use
+``CameraManager.get_events()`` to reset the eventfd and get the events.
+
+The CameraManager events (CameraAdded and CameraRemoved) are always enabled, but
+of the Camera events only RequestCompleted is enabled by default. To enable
+Disconnect or BufferCompleted event, use ``Camera.enable_camera_event()``.
+
+The ``Camera.stop()`` method will return all events related to that Camera from
+the event queue.
Controls & Properties
---------------------
diff --git a/src/py/libcamera/py_camera_manager.cpp b/src/py/libcamera/py_camera_manager.cpp
index 9ccb7aad..83c2b063 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 +36,24 @@ 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();
+}
+
+void PyCameraManager::init()
+{
+ /* Always enable RequestCompleted for all cameras by default */
+ for (auto cam : cameraManager_->cameras())
+ setCameraEventFlag(cam, CameraEventType::RequestCompleted, true);
}
py::list PyCameraManager::cameras()
@@ -60,6 +74,43 @@ 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 +123,207 @@ 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();
+ 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);
+}
+
+bool PyCameraManager::getCameraEventFlag(std::shared_ptr<Camera> camera, CameraEventType event_type)
+{
+ const uint32_t evbit = 1 << (uint32_t)event_type;
+ uint32_t mask = 0;
+
+ if (auto it = camera_event_masks_.find(camera); it != camera_event_masks_.end())
+ mask = it->second;
+
+ return !!(mask & evbit);
+}
+
+void PyCameraManager::setCameraEventFlag(std::shared_ptr<Camera> camera, CameraEventType event_type, bool value)
+{
+ switch (event_type) {
+ case CameraEventType::RequestCompleted:
+ case CameraEventType::BufferCompleted:
+ case CameraEventType::Disconnect:
+ break;
+
+ default:
+ throw std::runtime_error("Bad camera event type");
+ }
+
+ const uint32_t evbit = 1 << (uint32_t)event_type;
+ uint32_t mask = 0;
+
+ if (auto it = camera_event_masks_.find(camera); it != camera_event_masks_.end())
+ mask = it->second;
+
+ bool old_val = !!(mask & evbit);
+
+ if (old_val == value)
+ return;
+
+ if (value)
+ mask |= evbit;
+ else
+ mask &= ~evbit;
+
+ camera_event_masks_[camera] = mask;
+
+ switch (event_type) {
+ case CameraEventType::RequestCompleted:
+ if (value) {
+ camera->requestCompleted.connect(camera.get(), [cm = this->shared_from_this(), camera](Request *req) {
+ cm->handleRequestCompleted(camera, req);
+ });
+ } else {
+ camera->requestCompleted.disconnect();
+ }
+ break;
+
+ case CameraEventType::BufferCompleted:
+ if (value) {
+ camera->bufferCompleted.connect(camera.get(), [cm = this->shared_from_this(), camera](Request *req, FrameBuffer *fb) {
+ cm->handleBufferCompleted(camera, req, fb);
+ });
+ } else {
+ camera->bufferCompleted.disconnect();
+ }
+ break;
+
+ case CameraEventType::Disconnect:
+ if (value) {
+ camera->disconnected.connect(camera.get(), [cm = this->shared_from_this(), camera]() {
+ cm->handleDisconnected(camera);
+ });
+ } else {
+ camera->disconnected.disconnect();
+ }
+ break;
+ default:
+ ASSERT(false);
+ }
}
void PyCameraManager::writeFd()
@@ -116,16 +353,24 @@ 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 3574db23..31747547 100644
--- a/src/py/libcamera/py_camera_manager.h
+++ b/src/py/libcamera/py_camera_manager.h
@@ -13,12 +13,56 @@
using namespace libcamera;
-class PyCameraManager
+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 std::enable_shared_from_this<PyCameraManager>
{
public:
PyCameraManager();
~PyCameraManager();
+ void init();
+
pybind11::list cameras();
std::shared_ptr<Camera> get(const std::string &name) { return cameraManager_->get(name); }
@@ -26,20 +70,33 @@ 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 getCameraEventFlag(std::shared_ptr<Camera> camera, CameraEventType event_type);
+ void setCameraEventFlag(std::shared_ptr<Camera> camera, CameraEventType event_type, bool value);
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);
+
+ std::map<std::shared_ptr<Camera>, uint32_t> camera_event_masks_;
};
diff --git a/src/py/libcamera/py_main.cpp b/src/py/libcamera/py_main.cpp
index 5a5f1a37..981a3070 100644
--- a/src/py/libcamera/py_main.cpp
+++ b/src/py/libcamera/py_main.cpp
@@ -110,6 +110,7 @@ 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, std::shared_ptr<PyCameraManager>>(m, "CameraManager");
auto pyCamera = py::class_<Camera, PyCameraSmartPtr<Camera>>(m, "Camera");
auto pyCameraConfiguration = py::class_<CameraConfiguration>(m, "CameraConfiguration");
@@ -136,12 +137,27 @@ 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();
if (!cm) {
cm = std::make_shared<PyCameraManager>();
+ cm->init();
gCameraManager = cm;
}
@@ -153,10 +169,33 @@ 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);
pyCamera
.def_property_readonly("id", &Camera::id)
+
+ .def("get_camera_event_enabled",
+ [](Camera &self, CameraEventType type) {
+ auto cm = gCameraManager.lock();
+ return cm->getCameraEventFlag(self.shared_from_this(), type);
+ })
+
+ .def("enable_camera_event",
+ [](Camera &self, CameraEventType type) {
+ auto cm = gCameraManager.lock();
+ cm->setCameraEventFlag(self.shared_from_this(), type, true);
+ })
+
+ .def("disable_camera_event",
+ [](Camera &self, CameraEventType type) {
+ auto cm = gCameraManager.lock();
+ cm->setCameraEventFlag(self.shared_from_this(), type, false);
+ })
+
.def("acquire", [](Camera &self) {
int ret = self.acquire();
if (ret)
@@ -173,11 +212,6 @@ PYBIND11_MODULE(_libcamera, m)
const std::unordered_map<const ControlId *, py::object> &controls) {
/* \todo What happens if someone calls start() multiple times? */
- auto cm = gCameraManager.lock();
- ASSERT(cm);
-
- self.requestCompleted.connect(cm.get(), &PyCameraManager::handleRequestCompleted);
-
ControlList controlList(self.controls());
for (const auto &[id, obj] : controls) {
@@ -187,7 +221,6 @@ PYBIND11_MODULE(_libcamera, m)
int ret = self.start(&controlList);
if (ret) {
- self.requestCompleted.disconnect();
throw std::system_error(-ret, std::generic_category(),
"Failed to start camera");
}
@@ -196,11 +229,16 @@ PYBIND11_MODULE(_libcamera, m)
.def("stop", [](Camera &self) {
int ret = self.stop();
- self.requestCompleted.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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