]> sigrok.org Git - libsigrok.git/blobdiff - session.c
Code drop from DreamSourceLabs first source release.
[libsigrok.git] / session.c
index 210b73bad8c50e592ec3d65596d4b475f0f26eaf..29e19085434bb67acbc9665b129d64d492812c8b 100644 (file)
--- a/session.c
+++ b/session.c
@@ -1,7 +1,7 @@
 /*
- * This file is part of the sigrok project.
+ * This file is part of the libsigrok project.
  *
- * Copyright (C) 2010 Bert Vermeulen <bert@biot.com>
+ * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
-#include <zip.h>
-#include <sigrok.h>
+#include <glib.h>
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+/* 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.
+ */
 
-/* There can only be one session at a time. */
-struct session *session;
+/**
+ * @defgroup grp_session Session handling
+ *
+ * Creating, using, or destroying libsigrok sessions.
+ *
+ * @{
+ */
 
-struct session *session_load(const char *filename)
-{
-       struct session *session;
+struct source {
+       int timeout;
+       sr_receive_data_callback_t cb;
+       void *cb_data;
 
-       /* TODO: Implement. */
-       session = NULL;
+       /* 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;
+};
 
-       /* QUICK HACK */
-       filename = filename;
+struct datafeed_callback {
+       sr_datafeed_callback_t cb;
+       void *cb_data;
+};
 
-       return session;
-}
+/* There can only be one session at a time. */
+/* 'session' is not static, it's used elsewhere (via 'extern'). */
+struct sr_session *session;
 
-struct session *session_new(void)
+/**
+ * Create a new session.
+ *
+ * @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.
+ */
+SR_API struct sr_session *sr_session_new(void)
 {
-       session = calloc(1, sizeof(struct session));
+       if (!(session = g_try_malloc0(sizeof(struct sr_session)))) {
+               sr_err("Session malloc failed.");
+               return NULL;
+       }
+
+       session->source_timeout = -1;
+       session->abort_session = FALSE;
+//     g_mutex_init(&session->stop_mutex);
 
        return session;
 }
 
-void session_destroy(void)
+/**
+ * Destroy the current session.
+ *
+ * This frees up all memory used by the session.
+ *
+ * @return SR_OK upon success, SR_ERR_BUG if no session exists.
+ */
+SR_API int sr_session_destroy(void)
 {
-       g_slist_free(session->devices);
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
+       }
+
+       sr_session_dev_remove_all();
+
+    sr_session_datafeed_callback_remove_all();
+
+    if (session->sources) {
+        g_free(session->sources);
+        session->sources = NULL;
+    }
+
+    if (session->pollfds) {
+        g_free(session->pollfds);
+        session->pollfds = NULL;
+    }
+
+       /* TODO: Error checks needed? */
 
-       /* TODO: Loop over protocols and free them. */
+//     g_mutex_clear(&session->stop_mutex);
 
        g_free(session);
-}
+       session = NULL;
 
-void session_device_clear(void)
-{
-       g_slist_free(session->devices);
-       session->devices = NULL;
+       return SR_OK;
 }
 
-int session_device_add(struct device *device)
+/**
+ * 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.
+ *
+ * @return SR_OK upon success, SR_ERR_BUG if no session exists.
+ */
+SR_API int sr_session_dev_remove_all(void)
 {
-       int ret;
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
+       }
 
-       ret = device->plugin->open(device->plugin_index);
-       if (ret == SIGROK_OK)
-               session->devices = g_slist_append(session->devices, device);
+       g_slist_free(session->devs);
+       session->devs = NULL;
 
-       return ret;
+       return SR_OK;
 }
 
-void session_pa_clear(void)
+/**
+ * Add a device instance to the current session.
+ *
+ * @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(const struct sr_dev_inst *sdi)
 {
-       /*
-        * The protocols are pointers to the global set of PA plugins,
-        * so don't free them.
-        */
-       g_slist_free(session->analyzers);
-       session->analyzers = NULL;
-}
 
-void session_pa_add(struct analyzer *an)
-{
-       session->analyzers = g_slist_append(session->analyzers, an);
+       if (!sdi) {
+               sr_err("%s: sdi was NULL", __func__);
+               return SR_ERR_ARG;
+       }
+
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
+       }
+
+       /* 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, (gpointer)sdi);
+               return SR_OK;
+       }
+
+       /* 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;
+       }
+
+       session->devs = g_slist_append(session->devs, (gpointer)sdi);
+
+       return SR_OK;
 }
 
-void session_datafeed_callback_clear(void)
+/**
+ * Remove all datafeed callbacks in the current session.
+ *
+ * @return SR_OK upon success, SR_ERR_BUG if no session exists.
+ */
+SR_API int sr_session_datafeed_callback_remove_all(void)
 {
-       g_slist_free(session->datafeed_callbacks);
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
+       }
+
+       g_slist_free_full(session->datafeed_callbacks, g_free);
        session->datafeed_callbacks = NULL;
+
+       return SR_OK;
 }
 
-void session_datafeed_callback_add(datafeed_callback callback)
+/**
+ * Add a datafeed callback to the current session.
+ *
+ * @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, void *cb_data)
 {
+       struct datafeed_callback *cb_struct;
+
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
+       }
+
+       if (!cb) {
+               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, callback);
+           g_slist_append(session->datafeed_callbacks, cb_struct);
+
+       return SR_OK;
 }
 
-int session_start(void)
+static int sr_session_run_poll(void)
 {
-       struct device *device;
+       unsigned int i;
+       int ret;
+
+       while (session->num_sources > 0) {
+               ret = g_poll(session->pollfds, session->num_sources,
+                               session->source_timeout);
+               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;
+}
+
+/**
+ * Start a session.
+ *
+ * There can only be one session at a time.
+ *
+ * @return SR_OK upon success, SR_ERR upon errors.
+ */
+SR_API int sr_session_start(void)
+{
+       struct sr_dev_inst *sdi;
        GSList *l;
        int ret;
 
-       g_message("starting acquisition");
-       for (l = session->devices; l; l = l->next) {
-               device = l->data;
-               if ((ret = device->plugin->start_acquisition(
-                               device->plugin_index, device)) != SIGROK_OK)
+       if (!session) {
+               sr_err("%s: session was NULL; a session must be "
+                      "created before starting it.", __func__);
+               return SR_ERR_BUG;
+       }
+
+       if (!session->devs) {
+               sr_err("%s: session->devs was NULL; a session "
+                      "cannot be started without devices.", __func__);
+               return SR_ERR_BUG;
+       }
+
+       sr_info("Starting.");
+
+       ret = SR_OK;
+       for (l = session->devs; l; l = l->next) {
+               sdi = l->data;
+               if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
+                       sr_err("%s: could not start an acquisition "
+                              "(%d)", __func__, ret);
                        break;
+               }
        }
 
+       /* TODO: What if there are multiple devices? Which return code? */
+
        return ret;
 }
 
-void session_stop(void)
+/**
+ * Run the session.
+ *
+ * @return SR_OK upon success, SR_ERR_BUG upon errors.
+ */
+SR_API int sr_session_run(void)
+{
+       if (!session) {
+               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("%s: session->devs was NULL; a session "
+                      "cannot be run without devices.", __func__);
+               return SR_ERR_BUG;
+       }
+
+       sr_info("Running.");
+
+       /* Do we have real sources? */
+       if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
+               /* Dummy source, freewheel over it. */
+               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();
+       }
+
+       return SR_OK;
+}
+
+/**
+ * Stop the current session.
+ *
+ * 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.
+ */
+SR_PRIV int sr_session_stop_sync(void)
 {
-       struct device *device;
+       struct sr_dev_inst *sdi;
        GSList *l;
 
-       g_message("stopping acquisition");
-       for (l = session->devices; l; l = l->next) {
-               device = l->data;
-               device->plugin->stop_acquisition(device->plugin_index, device);
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
        }
+
+       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, NULL);
+               }
+       }
+
+       return SR_OK;
+}
+
+/**
+ * Stop the current session.
+ *
+ * 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)
+{
+       if (!session) {
+               sr_err("%s: session was NULL", __func__);
+               return SR_ERR_BUG;
+       }
+
+//     g_mutex_lock(&session->stop_mutex);
+       session->abort_session = TRUE;
+//     g_mutex_unlock(&session->stop_mutex);
+
+       return SR_OK;
 }
 
-void session_bus(struct device *device, struct datafeed_packet *packet)
+/**
+ * Debug helper.
+ *
+ * @param packet The packet to show debugging information for.
+ */
+static void datafeed_dump(const struct sr_datafeed_packet *packet)
+{
+       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 packet.");
+               break;
+       case SR_DF_TRIGGER:
+               sr_dbg("bus: Received SR_DF_TRIGGER packet.");
+               break;
+       case SR_DF_META:
+               sr_dbg("bus: Received SR_DF_META packet.");
+               break;
+       case SR_DF_LOGIC:
+               logic = packet->payload;
+               sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes).",
+                      logic->length);
+               break;
+       case SR_DF_ANALOG:
+               analog = packet->payload;
+               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 packet.");
+               break;
+       case 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 packet.");
+               break;
+       default:
+               sr_dbg("bus: Received unknown packet type: %d.", packet->type);
+               break;
+       }
+}
+
+/**
+ * Send a packet to whatever is listening on the datafeed bus.
+ *
+ * Hardware drivers use this to send a data packet to the frontend.
+ *
+ * @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(const struct sr_dev_inst *sdi,
+                           const struct sr_datafeed_packet *packet)
 {
        GSList *l;
-       datafeed_callback cb;
+       struct datafeed_callback *cb_struct;
+
+       if (!sdi) {
+               sr_err("%s: sdi was NULL", __func__);
+               return SR_ERR_ARG;
+       }
+
+       if (!packet) {
+               sr_err("%s: packet was NULL", __func__);
+               return SR_ERR_ARG;
+       }
 
-       /*
-        * TODO: Send packet through PA pipe, and send the output of that to
-        * the callbacks as well.
-        */
        for (l = session->datafeed_callbacks; l; l = l->next) {
-               cb = l->data;
-               cb(device, packet);
+               if (sr_log_loglevel_get() >= SR_LOG_DBG)
+                       datafeed_dump(packet);
+               cb_struct = l->data;
+               cb_struct->cb(sdi, packet, cb_struct->cb_data);
        }
+
+       return SR_OK;
 }
 
-void make_metadata(char *filename)
+/**
+ * Add an event source for a file descriptor.
+ *
+ * @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.
+ */
+static int _sr_session_source_add(GPollFD *pollfd, int timeout,
+    sr_receive_data_callback_t cb, const struct sr_dev_inst *sdi, gintptr poll_object)
 {
-       GSList *l, *p;
-       struct device *device;
-       struct probe *probe;
-       FILE *f;
-       int devcnt;
-
-       f = fopen(filename, "wb");
-
-       /* General */
-
-       /* Devices */
-       devcnt = 1;
-       for (l = session->devices; l; l = l->next) {
-               device = l->data;
-               fprintf(f, "[device]\n");
-               fprintf(f, "driver = %s\n", device->plugin->name);
-
-               if (device->datastore)
-                       fprintf(f, "capturefile = raw-%d\n", devcnt);
-
-               for (p = device->probes; p; p = p->next) {
-                       probe = p->data;
-                       if (probe->enabled) {
-                               fprintf(f, "probe %d", probe->index);
-                               if (probe->name)
-                                       fprintf(f, " name \"%s\"", probe->name);
-                               if (probe->trigger)
-                                       fprintf(f, " trigger \"%s\"",
-                                               probe->trigger);
-                               fprintf(f, "\n");
-                       }
-               }
-               devcnt++;
+       struct source *new_sources, *s;
+       GPollFD *new_pollfds;
+
+       if (!cb) {
+               sr_err("%s: cb was NULL", __func__);
+               return SR_ERR_ARG;
        }
 
-       /* TODO: Protocol analyzers */
+       /* Note: cb_data can be NULL, that's not a bug. */
 
-       fclose(f);
+       new_pollfds = g_try_realloc(session->pollfds,
+                       sizeof(GPollFD) * (session->num_sources + 1));
+       if (!new_pollfds) {
+               sr_err("%s: new_pollfds malloc failed", __func__);
+               return SR_ERR_MALLOC;
+       }
+
+       new_sources = g_try_realloc(session->sources, sizeof(struct source) *
+                       (session->num_sources + 1));
+       if (!new_sources) {
+               sr_err("%s: new_sources malloc failed", __func__);
+               return SR_ERR_MALLOC;
+       }
+
+       new_pollfds[session->num_sources] = *pollfd;
+       s = &new_sources[session->num_sources++];
+       s->timeout = timeout;
+       s->cb = cb;
+       s->cb_data = sdi;
+       s->poll_object = poll_object;
+       session->pollfds = new_pollfds;
+       session->sources = new_sources;
+
+       if (timeout != session->source_timeout && timeout > 0
+           && (session->source_timeout == -1 || timeout < session->source_timeout))
+               session->source_timeout = timeout;
+
+       return SR_OK;
 }
 
-int session_save(char *filename)
+/**
+ * Add an event source for a file descriptor.
+ *
+ * @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, const struct sr_dev_inst *sdi)
 {
-       GSList *l, *d;
-       struct device *device;
-       struct datastore *ds;
-       struct zip *zipfile;
-       struct zip_source *src;
-       int bufcnt, devcnt, tmpfile, ret, error;
-       char version[1], rawname[16], metafile[32], *buf;
-
-       /* Quietly delete it first, libzip wants replace ops otherwise. */
-       unlink(filename);
-
-       if (!(zipfile = zip_open(filename, ZIP_CREATE, &error)))
-               return SIGROK_ERR;
-
-       /* Version */
-       version[0] = '1';
-       if (!(src = zip_source_buffer(zipfile, version, 1, 0)))
-               return SIGROK_ERR;
-       if (zip_add(zipfile, "version", src) == -1) {
-               g_message("error saving version into zipfile: %s",
-                         zip_strerror(zipfile));
-               return SIGROK_ERR;
-       }
-
-       /* Metadata */
-       strcpy(metafile, "sigrok-meta-XXXXXX");
-       if ((tmpfile = g_mkstemp(metafile)) == -1)
-               return SIGROK_ERR;
-       close(tmpfile);
-       make_metadata(metafile);
-       if (!(src = zip_source_file(zipfile, metafile, 0, -1)))
-               return SIGROK_ERR;
-       if (zip_add(zipfile, "metadata", src) == -1)
-               return SIGROK_ERR;
-       unlink(metafile);
-
-       /* Raw */
-       devcnt = 1;
-       for (l = session->devices; l; l = l->next) {
-               device = l->data;
-               ds = device->datastore;
-               if (ds) {
-                       buf = malloc(ds->num_units * ds->ds_unitsize +
-                                  DATASTORE_CHUNKSIZE);
-                       bufcnt = 0;
-                       for (d = ds->chunklist; d; d = d->next) {
-                               memcpy(buf + bufcnt, d->data,
-                                      DATASTORE_CHUNKSIZE);
-                               bufcnt += DATASTORE_CHUNKSIZE;
-                       }
-                       if (!(src = zip_source_buffer(zipfile, buf,
-                                      ds->num_units * ds->ds_unitsize, TRUE)))
-                               return SIGROK_ERR;
-                       snprintf(rawname, 15, "raw-%d", devcnt);
-                       if (zip_add(zipfile, rawname, src) == -1)
-                               return SIGROK_ERR;
-               }
-               devcnt++;
+       GPollFD p;
+
+       p.fd = fd;
+       p.events = events;
+
+    return _sr_session_source_add(&p, timeout, cb, sdi, (gintptr)fd);
+}
+
+/**
+ * Add an event source for a GPollFD.
+ *
+ * @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, const struct sr_dev_inst *sdi)
+{
+    return _sr_session_source_add(pollfd, timeout, cb,
+                      sdi, (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, const struct sr_dev_inst *sdi)
+{
+       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, sdi, (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.
+ */
+static int _sr_session_source_remove(gintptr poll_object)
+{
+       struct source *new_sources;
+       GPollFD *new_pollfds;
+       unsigned int old;
+
+       if (!session->sources || !session->num_sources) {
+               sr_err("%s: sources was NULL", __func__);
+               return SR_ERR_BUG;
        }
 
-       if ((ret = zip_close(zipfile)) == -1) {
-               g_message("error saving zipfile: %s", zip_strerror(zipfile));
-               return SIGROK_ERR;
+       for (old = 0; old < session->num_sources; old++) {
+               if (session->sources[old].poll_object == poll_object)
+                       break;
        }
 
-       return SIGROK_OK;
+       /* fd not found, nothing to do */
+       if (old == session->num_sources)
+               return SR_OK;
+
+       session->num_sources -= 1;
+
+       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(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(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;
+       }
+
+       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);
+}
+
+/** @} */