Remove socket read management by systemd event

loop and use classic thread with a blocking
read

Change-Id: Iac5428009b57c727bb32bd4893bc3fe282ba35c7
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

6 files changed, 62 insertions, 83 deletions

diff --git a/src/can-utils.cpp b/src/can-utils.cpp
index 8a91bd1..c6f2d57 100644
--- a/src/can-utils.cpp
+++ b/src/can-utils.cpp
@@ -28,7 +28,6 @@
 #include <sys/socket.h>
 #include <json-c/json.h>
 #include <linux/can/raw.h>
-#include <systemd/sd-event.h>
 
 extern "C"
 {
@@ -187,7 +186,6 @@ int can_bus_t::init_can_dev()
 		t = devices_name.size();
 		i=0;
 
-		std::lock_guard<std::mutex> can_frame_lock(can_frame_mutex);
 		for(const auto& device : devices_name)
 		{
 			can_bus_dev_t can_bus_device_handler(device);
@@ -197,7 +195,6 @@ int can_bus_t::init_can_dev()
 				ERROR(binder_interface, "Can't open device %s", device);
 			can_bus_device_handler.start_reading(std::ref(*this));
 		}
-		can_frame_mutex.unlock();
 
 		NOTICE(binder_interface, "Initialized %d/%d can bus device(s)", i, t);
 		return 0;
@@ -301,15 +298,6 @@ bool can_bus_t::has_vehicle_message() const
 
 /********************************************************************************
 *
-*		This is the sd_event_add_io callback function declaration. 
-*		Its implementation can be found into low-can-binding.cpp.
-*
-*********************************************************************************/
-
-int can_frame_received(sd_event_source *s, int fd, uint32_t revents, void *userdata);
-
-/********************************************************************************
-*
 *		can_bus_dev_t method implementation
 *
 *********************************************************************************/
@@ -319,22 +307,6 @@ can_bus_dev_t::can_bus_dev_t(const std::string &dev_name)
 {
 }
 
-int can_bus_dev_t::event_loop_connection()
-{
-	sd_event_source *source;
-	int rc;
-
-	/* adds to the event loop */
-	rc = sd_event_add_io(afb_daemon_get_event_loop(binder_interface->daemon), &source, can_socket_, EPOLLIN, can_frame_received, this);
-	if (rc < 0) {
-		close();
-		ERROR(binder_interface, "Can't coonect CAN device %s to the event loop", device_name_);
-	} else {
-		NOTICE(binder_interface, "Connected to %s", device_name_);
-	}
-	return rc;
-}
-
 int can_bus_dev_t::open()
 {
 	const int canfd_on = 1;
@@ -374,14 +346,9 @@ int can_bus_dev_t::open()
 
 			/* And bind it to txAddress */
 			if (::bind(can_socket_, (struct sockaddr *)&txAddress_, sizeof(txAddress_)) < 0)
-			{
 				ERROR(binder_interface, "Bind failed");
-			}
 			else
-			{
-				::fcntl(can_socket_, F_SETFL, O_NONBLOCK);
 				return 0;
-			}
 		}
 		close();
 	}
diff --git a/src/can-utils.hpp b/src/can-utils.hpp
index e4a3d34..11e19f3 100644
--- a/src/can-utils.hpp
+++ b/src/can-utils.hpp
@@ -326,15 +326,6 @@ class can_bus_dev_t {
 		can_bus_dev_t(const std::string& dev_name);
 
 		/**
-		 * @brief Connect to the application framework event loop and adding
-		 *  a watch on the socket that will wakeup reading thread that will
-		 * read the socket and fill can_bus_t object queue.
-		 *
-		 * @return 0 if success, anything else if not.
-		 */
-		int event_loop_connection();
-
-		/**
 		 * @brief Open the can socket and returning it 
 		 *
 		 * @return 
@@ -521,8 +512,7 @@ void pre_initialize(can_bus_dev_t* bus, bool writable, can_bus_dev_t* buses, con
 
 /**
  * @fn void post_initialize(can_bus_dev_t* bus, bool writable, can_bus_dev_t* buses, const int busCount);
- * @brief Post-initialize actions made after CAN bus initialization and before the
- * event loop connection.
+ * @brief Post-initialize actions made after CAN bus initialization
  *
  * @param[in] bus - A CanBus struct defining the bus's metadata
  * @param[in] writable - configure the controller in a writable mode. If false, it will be
diff --git a/src/can_reader.cpp b/src/can_reader.cpp
index e2f6277..018c7cb 100644
--- a/src/can_reader.cpp
+++ b/src/can_reader.cpp
@@ -27,13 +27,7 @@ void can_reader(can_bus_dev_t &can_bus_dev, can_bus_t& can_bus)
 
 	while(can_bus_dev.is_running())
 	{
-		/* Declare and take lock ownership of can_frame_mutex.
-		 * then waiting notification for a new can frame arrival
-		 */
-		std::unique_lock<std::mutex> can_frame_lock(can_frame_mutex);
-		new_can_frame.wait(can_frame_lock);
-			can_message.convert_from_canfd_frame(can_bus_dev.read());
-		can_frame_mutex.unlock();
+		can_message.convert_from_canfd_frame(can_bus_dev.read());
 
 		std::lock_guard<std::mutex> can_message_lock(can_message_mutex);
 			can_bus.push_new_can_message(can_message);
diff --git a/src/low-can-binding-new.cpp b/src/low-can-binding-new.cpp
index 3686c6b..13571f2 100644
--- a/src/low-can-binding-new.cpp
+++ b/src/low-can-binding-new.cpp
@@ -23,6 +23,65 @@
 *		Subscription and unsubscription
 *
 *********************************************************************************/
+static int subscribe_unsubscribe_signal(struct afb_req request, const std::string& sig)
+{
+	int ret;
+
+	// TODO: lock the subscribed_signals when insert/remove
+	const auto& ss_i = subscribed_signals.find(sig);
+	if (ss_i != subscribed_signals.end())
+	{
+		if(!afb_event_is_valid(ss_i->second))
+		{
+			if(!subscribe)
+			{
+				NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
+				ret = 1;
+			}
+			else
+			{
+				ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
+				if (!afb_event_is_valid(ss_i->second)) 
+				{
+					ERROR(binder_interface, "Can't create an event, something goes wrong.");
+					ret = 0;
+				}
+			}
+		}
+	}
+	else
+	{
+		subscribed_signals[sig] = afb_daemon_make_event(binder_interface->daemon, sig);
+		if (!afb_event_is_valid(ss_i->second)) 
+		{
+			ERROR(binder_interface, "Can't create an event, something goes wrong.");
+			ret = 0;
+		}
+	}
+
+	if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, subscribed_signals[sig])) < 0)
+	{
+		ERROR(binder_interface, "Operation goes wrong for signal: %s", sig);
+		ret = 0;
+	}
+	else
+		ret = 1;
+	
+	return ret;
+}
+
+static int subscribe_signals(struct afb_req request, const std::vector<std::string>& signals)
+{
+	int ret = 0;
+
+	for(const auto& signal_i : signals)
+	{
+		ret = subscribe_signal(request, subscribe, signal_i);
+		if(ret == 0)
+			return ret;
+	}
+	return ret;
+}
 
 std::vector<std::string> get_name(struct afb_req request)
 {
diff --git a/src/low-can-binding.cpp b/src/low-can-binding.cpp
index ea8803f..2151790 100644
--- a/src/low-can-binding.cpp
+++ b/src/low-can-binding.cpp
@@ -54,34 +54,6 @@ can_bus_t *can_bus_handler;
 
 /********************************************************************************
 *
-*		Event management
-*
-*********************************************************************************/
-int can_frame_received(sd_event_source *s, int fd, uint32_t revents, void *userdata)
-{
-	can_bus_dev_t *can_bus_dev = (can_bus_dev_t*)userdata;
-
-	/* Notify reading thread that there is something to read */
-	if ((revents & EPOLLIN) != 0) {
-		new_can_frame.notify_one();
-	}
-
-	/* check if error or hangup and reopen the socket and event_loop. 
-	 * socket is protected by a mutex */
-	if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
-	{
-		std::lock_guard<std::mutex> can_frame_lock(can_frame_mutex);
-		sd_event_source_unref(s);
-		can_bus_dev->close();
-		can_bus_dev->open();
-		can_bus_dev->start_reading(*can_bus_handler);
-		can_bus_dev->event_loop_connection();
-	}
-
-	return 0;
-}
-/********************************************************************************
-*
 *		Subscription and unsubscription
 *
 *********************************************************************************/
diff --git a/src/low-can-binding.hpp b/src/low-can-binding.hpp
index 11df1f4..b2b544f 100644
--- a/src/low-can-binding.hpp
+++ b/src/low-can-binding.hpp
@@ -23,7 +23,4 @@
 
 extern "C" struct afb_binding_interface;
 
-extern const struct afb_binding_interface *binder_interface;
-
-extern std::condition_variable new_can_frame;
-extern std::mutex can_frame_mutex;
\ No newline at end of file
+extern const struct afb_binding_interface *binder_interface;
\ No newline at end of file