libcamera: ipa_manager: Remove singleton requirement

The IPAManager class implements a singleton pattern due to the need of
accessing the instance in a static member function. The function now
takes a pointer to a PipelineHandler, which we can use to access the
CameraManager, and from there, the IPAManager.

Add accessors to the internal API to expose the CameraManager from the
PipelineHandler, and the IPAManager from the CameraManager. This
requires allocating the IPAManager dynamically to avoid a loop in
includes. Use those accessors to replace the IPAManager singleton.

Update the IPA interface unit test to instantiate a CameraManager
instead of an IPAManager and ProcessManager, to reflect the new way that
the IPAManager is accessed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/camera_manager.h

@@ -19,13 +19,14 @@
 #include <libcamera/base/thread.h>
 #include <libcamera/base/thread_annotations.h>
 
-#include "libcamera/internal/ipa_manager.h"
 #include "libcamera/internal/process.h"
 
 namespace libcamera {
 
 class Camera;
 class DeviceEnumerator;
+class IPAManager;
+class PipelineHandlerFactoryBase;
 
 class CameraManager::Private : public Extensible::Private, public Thread
 {
@@ -38,6 +39,8 @@ public:
 	void addCamera(std::shared_ptr<Camera> camera) LIBCAMERA_TSA_EXCLUDES(mutex_);
 	void removeCamera(std::shared_ptr<Camera> camera) LIBCAMERA_TSA_EXCLUDES(mutex_);
 
+	IPAManager *ipaManager() const { return ipaManager_.get(); }
+
 protected:
 	void run() override;
 
@@ -62,7 +65,7 @@ private:
 
 	std::unique_ptr<DeviceEnumerator> enumerator_;
 
-	IPAManager ipaManager_;
+	std::unique_ptr<IPAManager> ipaManager_;
 	ProcessManager processManager_;
 };
 

include/libcamera/internal/ipa_manager.h

@@ -15,6 +15,7 @@
 #include <libcamera/ipa/ipa_interface.h>
 #include <libcamera/ipa/ipa_module_info.h>
 
+#include "libcamera/internal/camera_manager.h"
 #include "libcamera/internal/ipa_module.h"
 #include "libcamera/internal/pipeline_handler.h"
 #include "libcamera/internal/pub_key.h"
@@ -34,11 +35,13 @@ public:
 					    uint32_t minVersion,
 					    uint32_t maxVersion)
 	{
-		IPAModule *m = self_->module(pipe, minVersion, maxVersion);
+		CameraManager *cm = pipe->cameraManager();
+		IPAManager *self = cm->_d()->ipaManager();
+		IPAModule *m = self->module(pipe, minVersion, maxVersion);
 		if (!m)
 			return nullptr;
 
-		std::unique_ptr<T> proxy = std::make_unique<T>(m, !self_->isSignatureValid(m));
+		std::unique_ptr<T> proxy = std::make_unique<T>(m, !self->isSignatureValid(m));
 		if (!proxy->isValid()) {
 			LOG(IPAManager, Error) << "Failed to load proxy";
 			return nullptr;
@@ -55,8 +58,6 @@ public:
 #endif
 
 private:
-	static IPAManager *self_;
-
 	void parseDir(const char *libDir, unsigned int maxDepth,
 		      std::vector<std::string> &files);
 	unsigned int addDir(const char *libDir, unsigned int maxDepth = 0);

include/libcamera/internal/pipeline_handler.h

@@ -70,6 +70,8 @@ public:
 
 	const char *name() const { return name_; }
 
+	CameraManager *cameraManager() const { return manager_; }
+
 protected:
 	void registerCamera(std::shared_ptr<Camera> camera);
 	void hotplugMediaDevice(MediaDevice *media);

src/libcamera/camera_manager.cpp

@@ -15,6 +15,7 @@
 
 #include "libcamera/internal/camera.h"
 #include "libcamera/internal/device_enumerator.h"
+#include "libcamera/internal/ipa_manager.h"
 #include "libcamera/internal/pipeline_handler.h"
 
 /**
@@ -39,6 +40,7 @@ LOG_DEFINE_CATEGORY(Camera)
 CameraManager::Private::Private()
 	: initialized_(false)
 {
+	ipaManager_ = std::make_unique<IPAManager>();
 }
 
 int CameraManager::Private::start()
@@ -252,6 +254,13 @@ void CameraManager::Private::removeCamera(std::shared_ptr<Camera> camera)
 }
 #endif /* __DOXYGEN_PUBLIC__ */
 
+/**
+ * \fn CameraManager::Private::ipaManager() const
+ * \brief Retrieve the IPAManager
+ * \context This function is \threadsafe.
+ * \return The IPAManager for this CameraManager
+ */
+
 /**
  * \class CameraManager
  * \brief Provide access and manage all cameras in the system

src/libcamera/ipa_manager.cpp

@@ -95,8 +95,6 @@ LOG_DEFINE_CATEGORY(IPAManager)
  * IPC.
  */
 
-IPAManager *IPAManager::self_ = nullptr;
-
 /**
  * \brief Construct an IPAManager instance
  *
@@ -105,10 +103,6 @@ IPAManager *IPAManager::self_ = nullptr;
  */
 IPAManager::IPAManager()
 {
-	if (self_)
-		LOG(IPAManager, Fatal)
-			<< "Multiple IPAManager objects are not allowed";
-
 #if HAVE_IPA_PUBKEY
 	if (!pubKey_.isValid())
 		LOG(IPAManager, Warning) << "Public key not valid";
@@ -153,16 +147,12 @@ IPAManager::IPAManager()
 	if (!ipaCount)
 		LOG(IPAManager, Warning)
 			<< "No IPA found in '" IPA_MODULE_DIR "'";
-
-	self_ = this;
 }
 
 IPAManager::~IPAManager()
 {
 	for (IPAModule *module : modules_)
 		delete module;
-
-	self_ = nullptr;
 }
 
 /**

src/libcamera/pipeline_handler.cpp

@@ -719,6 +719,13 @@ void PipelineHandler::disconnect()
  * \return The pipeline handler name
  */
 
+/**
+ * \fn PipelineHandler::cameraManager() const
+ * \brief Retrieve the CameraManager that this pipeline handler belongs to
+ * \context This function is \threadsafe.
+ * \return The CameraManager for this pipeline handler
+ */
+
 /**
  * \class PipelineHandlerFactoryBase
  * \brief Base class for pipeline handler factories

test/ipa/ipa_interface_test.cpp

@@ -20,11 +20,11 @@
 #include <libcamera/base/thread.h>
 #include <libcamera/base/timer.h>
 
+#include "libcamera/internal/camera_manager.h"
 #include "libcamera/internal/device_enumerator.h"
 #include "libcamera/internal/ipa_manager.h"
 #include "libcamera/internal/ipa_module.h"
 #include "libcamera/internal/pipeline_handler.h"
-#include "libcamera/internal/process.h"
 
 #include "test.h"
 
@@ -44,20 +44,20 @@ public:
 	{
 		delete notifier_;
 		ipa_.reset();
-		ipaManager_.reset();
+		cameraManager_.reset();
 	}
 
 protected:
 	int init() override
 	{
-		ipaManager_ = make_unique<IPAManager>();
+		cameraManager_ = make_unique<CameraManager>();
 
 		/* Create a pipeline handler for vimc. */
 		const std::vector<PipelineHandlerFactoryBase *> &factories =
 			PipelineHandlerFactoryBase::factories();
 		for (const PipelineHandlerFactoryBase *factory : factories) {
 			if (factory->name() == "vimc") {
-				pipe_ = factory->create(nullptr);
+				pipe_ = factory->create(cameraManager_.get());
 				break;
 			}
 		}
@@ -171,11 +171,9 @@ private:
 		}
 	}
 
-	ProcessManager processManager_;
-
 	std::shared_ptr<PipelineHandler> pipe_;
 	std::unique_ptr<ipa::vimc::IPAProxyVimc> ipa_;
-	std::unique_ptr<IPAManager> ipaManager_;
+	std::unique_ptr<CameraManager> cameraManager_;
 	enum ipa::vimc::IPAOperationCode trace_;
 	EventNotifier *notifier_;
 	int fd_;