X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=session.c;h=1cf4170e220a1904ee798cb0161a29e67fcbef90;hb=8819bf5a960c37561e2bbbffa2685ec477938083;hp=e9677bf939c7f5cf1b8ad99d2a40c239d0ec0c52;hpb=0687dfcde9eeebc2ee5fdc93af4a9a322ce9d071;p=libsigrok.git

diff --git a/session.c b/session.c
index e9677bf9..1cf4170e 100644
--- a/session.c
+++ b/session.c
@@ -1,5 +1,5 @@
 /*
- * This file is part of the sigrok project.
+ * This file is part of the libsigrok project.
  *
  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
  *
@@ -25,33 +25,53 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
-/* demo.c. TODO: Should not be global! */
-extern SR_PRIV GIOChannel channels[2];
+/* Message logging helpers with subsystem-specific prefix string. */
+#define LOG_PREFIX "session: "
+#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
+#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
+#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
+#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
+#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
+#define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
+
+/**
+ * @file
+ *
+ * Creating, using, or destroying libsigrok sessions.
+ */
+
+/**
+ * @defgroup grp_session Session handling
+ *
+ * Creating, using, or destroying libsigrok sessions.
+ *
+ * @{
+ */
 
 struct source {
 	int timeout;
 	sr_receive_data_callback_t cb;
 	void *cb_data;
+
+	/* This is used to keep track of the object (fd, pollfd or channel) which is
+	 * being polled and will be used to match the source when removing it again.
+	 */
+	gintptr poll_object;
+};
+
+struct datafeed_callback {
+	sr_datafeed_callback_t cb;
+	void *cb_data;
 };
 
 /* There can only be one session at a time. */
 /* 'session' is not static, it's used elsewhere (via 'extern'). */
 struct sr_session *session;
-static int num_sources = 0;
-
-/* Both "sources" and "pollfds" are of the same size and contain pairs of
- * descriptor and callback function. We can not embed the GPollFD into the
- * source struct since we want to be able to pass the array of all poll
- * descriptors to g_poll.
- */
-static struct source *sources = NULL;
-static GPollFD *pollfds;
-static int source_timeout = -1;
 
 /**
  * Create a new session.
  *
- * TODO: Should it use the file-global "session" variable or take an argument?
+ * @todo Should it use the file-global "session" variable or take an argument?
  *       The same question applies to all the other session functions.
  *
  * @return A pointer to the newly allocated session, or NULL upon errors.
@@ -59,10 +79,15 @@ static int source_timeout = -1;
 SR_API struct sr_session *sr_session_new(void)
 {
 	if (!(session = g_try_malloc0(sizeof(struct sr_session)))) {
-		sr_err("session: %s: session malloc failed", __func__);
-		return NULL; /* TODO: SR_ERR_MALLOC? */
+		sr_err("Session malloc failed.");
+		return NULL;
 	}
 
+	session->source_timeout = -1;
+	session->running = FALSE;
+	session->abort_session = FALSE;
+	g_mutex_init(&session->stop_mutex);
+
 	return session;
 }
 
@@ -76,16 +101,15 @@ SR_API struct sr_session *sr_session_new(void)
 SR_API int sr_session_destroy(void)
 {
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	g_slist_free(session->devs);
-	session->devs = NULL;
+	sr_session_dev_remove_all();
 
 	/* TODO: Error checks needed? */
 
-	/* TODO: Loop over protocol decoders and free them. */
+	g_mutex_clear(&session->stop_mutex);
 
 	g_free(session);
 	session = NULL;
@@ -94,7 +118,7 @@ SR_API int sr_session_destroy(void)
 }
 
 /**
- * Remove all the devices from the current session. TODO?
+ * Remove all the devices from the current session.
  *
  * The session itself (i.e., the struct sr_session) is not free'd and still
  * exists after this function returns.
@@ -104,7 +128,7 @@ SR_API int sr_session_destroy(void)
 SR_API int sr_session_dev_remove_all(void)
 {
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
@@ -115,49 +139,78 @@ SR_API int sr_session_dev_remove_all(void)
 }
 
 /**
- * Add a device to the current session.
+ * Add a device instance to the current session.
  *
- * @param dev The device to add to the current session. Must not be NULL.
- *            Also, dev->driver and dev->driver->dev_open must not be NULL.
+ * @param sdi The device instance to add to the current session. Must not
+ *            be NULL. Also, sdi->driver and sdi->driver->dev_open must
+ *            not be NULL.
  *
  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
  */
-SR_API int sr_session_dev_add(struct sr_dev *dev)
+SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
 {
 	int ret;
 
-	if (!dev) {
-		sr_err("session: %s: dev was NULL", __func__);
+	if (!sdi) {
+		sr_err("%s: sdi was NULL", __func__);
 		return SR_ERR_ARG;
 	}
 
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	/* If dev->driver is NULL, this is a virtual device. */
-	if (!dev->driver) {
-		sr_dbg("session: %s: dev->driver was NULL, this seems to be "
+	/* If sdi->driver is NULL, this is a virtual device. */
+	if (!sdi->driver) {
+		sr_dbg("%s: sdi->driver was NULL, this seems to be "
 		       "a virtual device; continuing", __func__);
 		/* Just add the device, don't run dev_open(). */
-		session->devs = g_slist_append(session->devs, dev);
+		session->devs = g_slist_append(session->devs, (gpointer)sdi);
 		return SR_OK;
 	}
 
-	/* dev->driver is non-NULL (i.e. we have a real device). */
-	if (!dev->driver->dev_open) {
-		sr_err("session: %s: dev->driver->dev_open was NULL",
-		       __func__);
+	/* sdi->driver is non-NULL (i.e. we have a real device). */
+	if (!sdi->driver->dev_open) {
+		sr_err("%s: sdi->driver->dev_open was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	if ((ret = dev->driver->dev_open(dev->driver_index)) != SR_OK) {
-		sr_err("session: %s: dev_open failed (%d)", __func__, ret);
-		return ret;
+	session->devs = g_slist_append(session->devs, (gpointer)sdi);
+
+	if (session->running) {
+		/* Adding a device to a running session. Start acquisition
+		 * on that device now. */
+		if ((ret = sdi->driver->dev_acquisition_start(sdi,
+						(void *)sdi)) != SR_OK)
+			sr_err("Failed to start acquisition of device in "
+					"running session: %d", ret);
 	}
 
-	session->devs = g_slist_append(session->devs, dev);
+	return SR_OK;
+}
+
+/**
+ * List all device instances attached to the current session.
+ *
+ * @param devlist A pointer where the device instance list will be
+ *                stored on return. If no devices are in the session,
+ *                this will be NULL. Each element in the list points
+ *                to a struct sr_dev_inst *.
+ *                The list must be freed by the caller, but not the
+ *                elements pointed to.
+ *
+ * @return SR_OK upon success, SR_ERR upon invalid arguments.
+ */
+SR_API int sr_session_dev_list(GSList **devlist)
+{
+
+	*devlist = NULL;
+
+	if (!session)
+		return SR_ERR;
+
+	*devlist = g_slist_copy(session->devs);
 
 	return SR_OK;
 }
@@ -170,11 +223,11 @@ SR_API int sr_session_dev_add(struct sr_dev *dev)
 SR_API int sr_session_datafeed_callback_remove_all(void)
 {
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	g_slist_free(session->datafeed_callbacks);
+	g_slist_free_full(session->datafeed_callbacks, g_free);
 	session->datafeed_callbacks = NULL;
 
 	return SR_OK;
@@ -185,50 +238,85 @@ SR_API int sr_session_datafeed_callback_remove_all(void)
  *
  * @param cb Function to call when a chunk of data is received.
  *           Must not be NULL.
+ * @param cb_data Opaque pointer passed in by the caller.
  *
  * @return SR_OK upon success, SR_ERR_BUG if no session exists.
  */
-SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb)
+SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb, void *cb_data)
 {
+	struct datafeed_callback *cb_struct;
+
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
 	if (!cb) {
-		sr_err("session: %s: cb was NULL", __func__);
+		sr_err("%s: cb was NULL", __func__);
 		return SR_ERR_ARG;
 	}
 
+	if (!(cb_struct = g_try_malloc0(sizeof(struct datafeed_callback))))
+		return SR_ERR_MALLOC;
+
+	cb_struct->cb = cb;
+	cb_struct->cb_data = cb_data;
+
 	session->datafeed_callbacks =
-	    g_slist_append(session->datafeed_callbacks, cb);
+	    g_slist_append(session->datafeed_callbacks, cb_struct);
 
 	return SR_OK;
 }
 
 /**
- * TODO.
+ * Call every device in the session's callback.
+ *
+ * For sessions not driven by select loops such as sr_session_run(),
+ * but driven by another scheduler, this can be used to poll the devices
+ * from within that scheduler.
+ *
+ * @param block If TRUE, this call will wait for any of the session's
+ *              sources to fire an event on the file descriptors, or
+ *              any of their timeouts to activate. In other words, this
+ *              can be used as a select loop.
+ *              If FALSE, all sources have their callback run, regardless
+ *              of file descriptor or timeout status.
+ *
+ * @return SR_OK upon success, SR_ERR on errors.
  */
-static int sr_session_run_poll(void)
+static int sr_session_iteration(gboolean block)
 {
-	int ret, i;
-
-	while (session->running) {
-		ret = g_poll(pollfds, num_sources, source_timeout);
-
-		for (i = 0; i < num_sources; i++) {
-			if (pollfds[i].revents > 0 || (ret == 0
-				&& source_timeout == sources[i].timeout)) {
-				/*
-				 * Invoke the source's callback on an event,
-				 * or if the poll timeout out and this source
-				 * asked for that timeout.
-				 */
-				if (!sources[i].cb(pollfds[i].fd, pollfds[i].revents,
-						  sources[i].cb_data))
-					sr_session_source_remove(pollfds[i].fd);
-			}
+	unsigned int i;
+	int ret;
+
+	ret = g_poll(session->pollfds, session->num_sources,
+			block ? session->source_timeout : 0);
+	for (i = 0; i < session->num_sources; i++) {
+		if (session->pollfds[i].revents > 0 || (ret == 0
+			&& session->source_timeout == session->sources[i].timeout)) {
+			/*
+			 * Invoke the source's callback on an event,
+			 * or if the poll timed out and this source
+			 * asked for that timeout.
+			 */
+			if (!session->sources[i].cb(session->pollfds[i].fd,
+					session->pollfds[i].revents,
+					session->sources[i].cb_data))
+				sr_session_source_remove(session->sources[i].poll_object);
+		}
+		/*
+		 * We want to take as little time as possible to stop
+		 * the session if we have been told to do so. Therefore,
+		 * we check the flag after processing every source, not
+		 * just once per main event loop.
+		 */
+		g_mutex_lock(&session->stop_mutex);
+		if (session->abort_session) {
+			sr_session_stop_sync();
+			/* But once is enough. */
+			session->abort_session = FALSE;
 		}
+		g_mutex_unlock(&session->stop_mutex);
 	}
 
 	return SR_OK;
@@ -243,34 +331,30 @@ static int sr_session_run_poll(void)
  */
 SR_API int sr_session_start(void)
 {
-	struct sr_dev *dev;
+	struct sr_dev_inst *sdi;
 	GSList *l;
 	int ret;
 
 	if (!session) {
-		sr_err("session: %s: session was NULL; a session must be "
-		       "created first, before starting it.", __func__);
+		sr_err("%s: session was NULL; a session must be "
+		       "created before starting it.", __func__);
 		return SR_ERR_BUG;
 	}
 
 	if (!session->devs) {
-		/* TODO: Actually the case? */
-		sr_err("session: %s: session->devs was NULL; a session "
+		sr_err("%s: session->devs was NULL; a session "
 		       "cannot be started without devices.", __func__);
 		return SR_ERR_BUG;
 	}
 
-	/* TODO: Check driver_index validity? */
-
-	sr_info("session: starting");
+	sr_info("Starting.");
 
+	ret = SR_OK;
 	for (l = session->devs; l; l = l->next) {
-		dev = l->data;
-		/* TODO: Check for dev != NULL. */
-		if ((ret = dev->driver->dev_acquisition_start(
-				dev->driver_index, dev)) != SR_OK) {
-			sr_err("session: %s: could not start an acquisition "
-			       "(%d)", __func__, ret);
+		sdi = l->data;
+		if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
+			sr_err("%s: could not start an acquisition "
+			       "(%s)", __func__, sr_strerror(ret));
 			break;
 		}
 	}
@@ -283,57 +367,72 @@ SR_API int sr_session_start(void)
 /**
  * Run the session.
  *
- * TODO: Various error checks etc.
- *
  * @return SR_OK upon success, SR_ERR_BUG upon errors.
  */
 SR_API int sr_session_run(void)
 {
 	if (!session) {
-		sr_err("session: %s: session was NULL; a session must be "
+		sr_err("%s: session was NULL; a session must be "
 		       "created first, before running it.", __func__);
 		return SR_ERR_BUG;
 	}
 
 	if (!session->devs) {
 		/* TODO: Actually the case? */
-		sr_err("session: %s: session->devs was NULL; a session "
+		sr_err("%s: session->devs was NULL; a session "
 		       "cannot be run without devices.", __func__);
 		return SR_ERR_BUG;
 	}
-
-	sr_info("session: running");
 	session->running = TRUE;
 
+	sr_info("Running.");
+
 	/* Do we have real sources? */
-	if (num_sources == 1 && pollfds[0].fd == -1) {
+	if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
 		/* Dummy source, freewheel over it. */
-		while (session->running)
-			sources[0].cb(-1, 0, sources[0].cb_data);
+		while (session->num_sources)
+			session->sources[0].cb(-1, 0, session->sources[0].cb_data);
 	} else {
 		/* Real sources, use g_poll() main loop. */
-		sr_session_run_poll();
+		while (session->num_sources)
+			sr_session_iteration(TRUE);
 	}
 
 	return SR_OK;
 }
 
 /**
- * Halt the current session.
+ * Stop the current session.
  *
- * This requests the current session be stopped as soon as possible, for
- * example on receiving an SR_DF_END packet.
+ * The current session is stopped immediately, with all acquisition sessions
+ * being stopped and hardware drivers cleaned up.
+ *
+ * This must be called from within the session thread, to prevent freeing
+ * resources that the session thread will try to use.
  *
  * @return SR_OK upon success, SR_ERR_BUG if no session exists.
+ *
+ * @private
  */
-SR_API int sr_session_halt(void)
+SR_PRIV int sr_session_stop_sync(void)
 {
+	struct sr_dev_inst *sdi;
+	GSList *l;
+
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	sr_info("session: halting");
+	sr_info("Stopping.");
+
+	for (l = session->devs; l; l = l->next) {
+		sdi = l->data;
+		if (sdi->driver) {
+			if (sdi->driver->dev_acquisition_stop)
+				sdi->driver->dev_acquisition_stop(sdi, sdi);
+		}
+	}
 	session->running = FALSE;
 
 	return SR_OK;
@@ -345,31 +444,23 @@ SR_API int sr_session_halt(void)
  * The current session is stopped immediately, with all acquisition sessions
  * being stopped and hardware drivers cleaned up.
  *
+ * If the session is run in a separate thread, this function will not block
+ * until the session is finished executing. It is the caller's responsibility
+ * to wait for the session thread to return before assuming that the session is
+ * completely decommissioned.
+ *
  * @return SR_OK upon success, SR_ERR_BUG if no session exists.
  */
 SR_API int sr_session_stop(void)
 {
-	struct sr_dev *dev;
-	GSList *l;
-
 	if (!session) {
-		sr_err("session: %s: session was NULL", __func__);
+		sr_err("%s: session was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	sr_info("session: stopping");
-	session->running = FALSE;
-
-	for (l = session->devs; l; l = l->next) {
-		dev = l->data;
-		/* Check for dev != NULL. */
-		if (dev->driver) {
-			if (dev->driver->dev_acquisition_stop)
-				dev->driver->dev_acquisition_stop(dev->driver_index, dev);
-			if (dev->driver->cleanup)
-				dev->driver->cleanup();
-		}
-	}
+	g_mutex_lock(&session->stop_mutex);
+	session->abort_session = TRUE;
+	g_mutex_unlock(&session->stop_mutex);
 
 	return SR_OK;
 }
@@ -379,45 +470,42 @@ SR_API int sr_session_stop(void)
  *
  * @param packet The packet to show debugging information for.
  */
-static void datafeed_dump(struct sr_datafeed_packet *packet)
+static void datafeed_dump(const struct sr_datafeed_packet *packet)
 {
-	struct sr_datafeed_logic *logic;
-	struct sr_datafeed_analog *analog;
+	const struct sr_datafeed_logic *logic;
+	const struct sr_datafeed_analog *analog;
 
 	switch (packet->type) {
 	case SR_DF_HEADER:
-		sr_dbg("bus: received SR_DF_HEADER");
+		sr_dbg("bus: Received SR_DF_HEADER packet.");
 		break;
 	case SR_DF_TRIGGER:
-		sr_dbg("bus: received SR_DF_TRIGGER");
+		sr_dbg("bus: Received SR_DF_TRIGGER packet.");
 		break;
-	case SR_DF_META_LOGIC:
-		sr_dbg("bus: received SR_DF_META_LOGIC");
+	case SR_DF_META:
+		sr_dbg("bus: Received SR_DF_META packet.");
 		break;
 	case SR_DF_LOGIC:
 		logic = packet->payload;
-		/* TODO: Check for logic != NULL. */
-		sr_dbg("bus: received SR_DF_LOGIC %" PRIu64 " bytes", logic->length);
-		break;
-	case SR_DF_META_ANALOG:
-		sr_dbg("bus: received SR_DF_META_LOGIC");
+		sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes).",
+		       logic->length);
 		break;
 	case SR_DF_ANALOG:
 		analog = packet->payload;
-		/* TODO: Check for analog != NULL. */
-		sr_dbg("bus: received SR_DF_ANALOG %d samples", analog->num_samples);
+		sr_dbg("bus: Received SR_DF_ANALOG packet (%d samples).",
+		       analog->num_samples);
 		break;
 	case SR_DF_END:
-		sr_dbg("bus: received SR_DF_END");
+		sr_dbg("bus: Received SR_DF_END packet.");
 		break;
 	case SR_DF_FRAME_BEGIN:
-		sr_dbg("bus: received SR_DF_FRAME_BEGIN");
+		sr_dbg("bus: Received SR_DF_FRAME_BEGIN packet.");
 		break;
 	case SR_DF_FRAME_END:
-		sr_dbg("bus: received SR_DF_FRAME_END");
+		sr_dbg("bus: Received SR_DF_FRAME_END packet.");
 		break;
 	default:
-		sr_dbg("bus: received unknown packet type %d", packet->type);
+		sr_dbg("bus: Received unknown packet type: %d.", packet->type);
 		break;
 	}
 }
@@ -427,153 +515,260 @@ static void datafeed_dump(struct sr_datafeed_packet *packet)
  *
  * Hardware drivers use this to send a data packet to the frontend.
  *
- * @param dev TODO.
+ * @param sdi TODO.
  * @param packet The datafeed packet to send to the session bus.
  *
  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
+ *
+ * @private
  */
-SR_PRIV int sr_session_send(struct sr_dev *dev,
-			    struct sr_datafeed_packet *packet)
+SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
+			    const struct sr_datafeed_packet *packet)
 {
 	GSList *l;
-	sr_datafeed_callback_t cb;
+	struct datafeed_callback *cb_struct;
 
-	if (!dev) {
-		sr_err("session: %s: dev was NULL", __func__);
+	if (!sdi) {
+		sr_err("%s: sdi was NULL", __func__);
 		return SR_ERR_ARG;
 	}
 
 	if (!packet) {
-		sr_err("session: %s: packet was NULL", __func__);
+		sr_err("%s: packet was NULL", __func__);
 		return SR_ERR_ARG;
 	}
 
 	for (l = session->datafeed_callbacks; l; l = l->next) {
 		if (sr_log_loglevel_get() >= SR_LOG_DBG)
 			datafeed_dump(packet);
-		cb = l->data;
-		/* TODO: Check for cb != NULL. */
-		cb(dev, packet);
+		cb_struct = l->data;
+		cb_struct->cb(sdi, packet, cb_struct->cb_data);
 	}
 
 	return SR_OK;
 }
 
 /**
- * TODO.
- *
- * TODO: More error checks etc.
+ * Add an event source for a file descriptor.
  *
- * @param fd TODO.
- * @param events TODO.
- * @param timeout TODO.
+ * @param pollfd The GPollFD.
+ * @param timeout Max time to wait before the callback is called, ignored if 0.
  * @param cb Callback function to add. Must not be NULL.
  * @param cb_data Data for the callback function. Can be NULL.
+ * @param poll_object TODO.
  *
  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
  *         SR_ERR_MALLOC upon memory allocation errors.
  */
-SR_API int sr_session_source_add(int fd, int events, int timeout,
-		sr_receive_data_callback_t cb, void *cb_data)
+static int _sr_session_source_add(GPollFD *pollfd, int timeout,
+	sr_receive_data_callback_t cb, void *cb_data, gintptr poll_object)
 {
 	struct source *new_sources, *s;
-	GPollFD *new_pollfds, *p;
+	GPollFD *new_pollfds;
 
 	if (!cb) {
-		sr_err("session: %s: cb was NULL", __func__);
+		sr_err("%s: cb was NULL", __func__);
 		return SR_ERR_ARG;
 	}
 
 	/* Note: cb_data can be NULL, that's not a bug. */
 
-	new_pollfds = g_try_realloc(pollfds, sizeof(GPollFD) * (num_sources + 1));
+	new_pollfds = g_try_realloc(session->pollfds,
+			sizeof(GPollFD) * (session->num_sources + 1));
 	if (!new_pollfds) {
-		sr_err("session: %s: new_sources malloc failed", __func__);
+		sr_err("%s: new_pollfds malloc failed", __func__);
 		return SR_ERR_MALLOC;
 	}
 
-	new_sources = g_try_realloc(sources, sizeof(struct source) * (num_sources + 1));
+	new_sources = g_try_realloc(session->sources, sizeof(struct source) *
+			(session->num_sources + 1));
 	if (!new_sources) {
-		sr_err("session: %s: new_sources malloc failed", __func__);
+		sr_err("%s: new_sources malloc failed", __func__);
 		return SR_ERR_MALLOC;
 	}
 
-	p = &new_pollfds[num_sources];
-	s = &new_sources[num_sources++];
-#ifdef _WIN32
-	g_io_channel_win32_make_pollfd(&channels[0],
-			events, p);
-#else
-	p->fd = fd;
-	p->events = events;
-#endif
+	new_pollfds[session->num_sources] = *pollfd;
+	s = &new_sources[session->num_sources++];
 	s->timeout = timeout;
 	s->cb = cb;
 	s->cb_data = cb_data;
-	pollfds = new_pollfds;
-	sources = new_sources;
+	s->poll_object = poll_object;
+	session->pollfds = new_pollfds;
+	session->sources = new_sources;
 
-	if (timeout != source_timeout && timeout > 0
-	    && (source_timeout == -1 || timeout < source_timeout))
-		source_timeout = timeout;
+	if (timeout != session->source_timeout && timeout > 0
+	    && (session->source_timeout == -1 || timeout < session->source_timeout))
+		session->source_timeout = timeout;
 
 	return SR_OK;
 }
 
 /**
- * Remove the source belonging to the specified file descriptor.
+ * Add an event source for a file descriptor.
  *
- * TODO: More error checks.
+ * @param fd The file descriptor.
+ * @param events Events to check for.
+ * @param timeout Max time to wait before the callback is called, ignored if 0.
+ * @param cb Callback function to add. Must not be NULL.
+ * @param cb_data Data for the callback function. Can be NULL.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors.
+ */
+SR_API int sr_session_source_add(int fd, int events, int timeout,
+		sr_receive_data_callback_t cb, void *cb_data)
+{
+	GPollFD p;
+
+	p.fd = fd;
+	p.events = events;
+
+	return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)fd);
+}
+
+/**
+ * Add an event source for a GPollFD.
  *
- * @param fd TODO.
+ * @param pollfd The GPollFD.
+ * @param timeout Max time to wait before the callback is called, ignored if 0.
+ * @param cb Callback function to add. Must not be NULL.
+ * @param cb_data Data for the callback function. Can be NULL.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors.
+ */
+SR_API int sr_session_source_add_pollfd(GPollFD *pollfd, int timeout,
+		sr_receive_data_callback_t cb, void *cb_data)
+{
+	return _sr_session_source_add(pollfd, timeout, cb,
+				      cb_data, (gintptr)pollfd);
+}
+
+/**
+ * Add an event source for a GIOChannel.
+ *
+ * @param channel The GIOChannel.
+ * @param events Events to poll on.
+ * @param timeout Max time to wait before the callback is called, ignored if 0.
+ * @param cb Callback function to add. Must not be NULL.
+ * @param cb_data Data for the callback function. Can be NULL.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors.
+ */
+SR_API int sr_session_source_add_channel(GIOChannel *channel, int events,
+		int timeout, sr_receive_data_callback_t cb, void *cb_data)
+{
+	GPollFD p;
+
+#ifdef _WIN32
+	g_io_channel_win32_make_pollfd(channel, events, &p);
+#else
+	p.fd = g_io_channel_unix_get_fd(channel);
+	p.events = events;
+#endif
+
+	return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)channel);
+}
+
+/**
+ * Remove the source belonging to the specified channel.
+ *
+ * @todo Add more error checks and logging.
+ *
+ * @param channel The channel for which the source should be removed.
  *
  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
  *         SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
  *         internal errors.
  */
-SR_API int sr_session_source_remove(int fd)
+static int _sr_session_source_remove(gintptr poll_object)
 {
 	struct source *new_sources;
 	GPollFD *new_pollfds;
-	int old;
+	unsigned int old;
 
-	if (!sources) {
-		sr_err("session: %s: sources was NULL", __func__);
+	if (!session->sources || !session->num_sources) {
+		sr_err("%s: sources was NULL", __func__);
 		return SR_ERR_BUG;
 	}
 
-	for (old = 0; old < num_sources; old++) {
-		if (pollfds[old].fd == fd)
+	for (old = 0; old < session->num_sources; old++) {
+		if (session->sources[old].poll_object == poll_object)
 			break;
 	}
 
 	/* fd not found, nothing to do */
-	if (old == num_sources)
+	if (old == session->num_sources)
 		return SR_OK;
 
-	num_sources -= 1;
+	session->num_sources -= 1;
 
-	if (old != num_sources) {
-		memmove(&pollfds[old], &pollfds[old+1],
-			(num_sources - old) * sizeof(GPollFD));
-		memmove(&sources[old], &sources[old+1],
-			(num_sources - old) * sizeof(struct source));
+	if (old != session->num_sources) {
+		memmove(&session->pollfds[old], &session->pollfds[old+1],
+			(session->num_sources - old) * sizeof(GPollFD));
+		memmove(&session->sources[old], &session->sources[old+1],
+			(session->num_sources - old) * sizeof(struct source));
 	}
 
-	new_pollfds = g_try_realloc(sources, sizeof(GPollFD) * num_sources);
-	if (!new_pollfds && num_sources > 0) {
-		sr_err("session: %s: new_sources malloc failed", __func__);
+	new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
+	if (!new_pollfds && session->num_sources > 0) {
+		sr_err("%s: new_pollfds malloc failed", __func__);
 		return SR_ERR_MALLOC;
 	}
 
-	new_sources = g_try_realloc(sources, sizeof(struct source) * num_sources);
-	if (!new_sources && num_sources > 0) {
-		sr_err("session: %s: new_sources malloc failed", __func__);
+	new_sources = g_try_realloc(session->sources, sizeof(struct source) * session->num_sources);
+	if (!new_sources && session->num_sources > 0) {
+		sr_err("%s: new_sources malloc failed", __func__);
 		return SR_ERR_MALLOC;
 	}
 
-	pollfds = new_pollfds;
-	sources = new_sources;
+	session->pollfds = new_pollfds;
+	session->sources = new_sources;
 
 	return SR_OK;
 }
+
+/**
+ * Remove the source belonging to the specified file descriptor.
+ *
+ * @param fd The file descriptor for which the source should be removed.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
+ *         internal errors.
+ */
+SR_API int sr_session_source_remove(int fd)
+{
+	return _sr_session_source_remove((gintptr)fd);
+}
+
+/**
+ * Remove the source belonging to the specified poll descriptor.
+ *
+ * @param pollfd The poll descriptor for which the source should be removed.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
+ *         internal errors.
+ */
+SR_API int sr_session_source_remove_pollfd(GPollFD *pollfd)
+{
+	return _sr_session_source_remove((gintptr)pollfd);
+}
+
+/**
+ * Remove the source belonging to the specified channel.
+ *
+ * @param channel The channel for which the source should be removed.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
+ *         internal errors.
+ */
+SR_API int sr_session_source_remove_channel(GIOChannel *channel)
+{
+	return _sr_session_source_remove((gintptr)channel);
+}
+
+/** @} */