Better error reporting on session start failure

[libsigrok.git] / session.c

diff --git a/session.c b/session.c
index 720b5ae10819908b63018e1c8095cbfceed5bc49..1cf4170e220a1904ee798cb0161a29e67fcbef90 100644 (file)
--- a/session.c
+++ b/session.c
@@ -84,6 +84,7 @@ SR_API struct sr_session *sr_session_new(void)
        }
 
        session->source_timeout = -1;
+       session->running = FALSE;
        session->abort_session = FALSE;
        g_mutex_init(&session->stop_mutex);
 
@@ -148,6 +149,7 @@ SR_API int sr_session_dev_remove_all(void)
  */
 SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
 {
+       int ret;
 
        if (!sdi) {
                sr_err("%s: sdi was NULL", __func__);
@@ -176,6 +178,40 @@ SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
 
        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);
+       }
+
+       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;
 }
 
@@ -239,9 +275,16 @@ SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb, void *cb_
  * 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.
  */
-SR_API int sr_session_iteration(gboolean block)
+static int sr_session_iteration(gboolean block)
 {
        unsigned int i;
        int ret;
@@ -311,7 +354,7 @@ SR_API int sr_session_start(void)
                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);
+                              "(%s)", __func__, sr_strerror(ret));
                        break;
                }
        }
@@ -340,6 +383,7 @@ SR_API int sr_session_run(void)
                       "cannot be run without devices.", __func__);
                return SR_ERR_BUG;
        }
+       session->running = TRUE;
 
        sr_info("Running.");
 
@@ -367,6 +411,8 @@ SR_API int sr_session_run(void)
  * resources that the session thread will try to use.
  *
  * @return SR_OK upon success, SR_ERR_BUG if no session exists.
+ *
+ * @private
  */
 SR_PRIV int sr_session_stop_sync(void)
 {
@@ -387,6 +433,7 @@ SR_PRIV int sr_session_stop_sync(void)
                                sdi->driver->dev_acquisition_stop(sdi, sdi);
                }
        }
+       session->running = FALSE;
 
        return SR_OK;
 }