]> sigrok.org Git - libsigrok.git/blobdiff - session.c
Bump package version to 0.2.1, libtool version to 1:1:0.
[libsigrok.git] / session.c
index 6a4a3c99704b4e2c5f371911594c685a9417ed06..15be92c8237a2b5a0c5627d250b9fadc4598995f 100644 (file)
--- 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>
  *
 #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
  *
@@ -50,6 +59,11 @@ struct source {
        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;
@@ -65,11 +79,13 @@ struct sr_session *session;
 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->abort_session = FALSE;
+       g_mutex_init(&session->stop_mutex);
 
        return session;
 }
@@ -84,7 +100,7 @@ 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;
        }
 
@@ -92,18 +108,14 @@ SR_API int sr_session_destroy(void)
 
        /* TODO: Error checks needed? */
 
+       g_mutex_clear(&session->stop_mutex);
+
        g_free(session);
        session = NULL;
 
        return SR_OK;
 }
 
-static void sr_dev_close(struct sr_dev_inst *sdi)
-{
-       if (sdi->driver && sdi->driver->dev_close)
-               sdi->driver->dev_close(sdi);
-}
-
 /**
  * Remove all the devices from the current session.
  *
@@ -115,11 +127,11 @@ static void sr_dev_close(struct sr_dev_inst *sdi)
 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;
        }
 
-       g_slist_free_full(session->devs, (GDestroyNotify)sr_dev_close);
+       g_slist_free(session->devs);
        session->devs = NULL;
 
        return SR_OK;
@@ -136,21 +148,20 @@ 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("session: %s: sdi was NULL", __func__);
+               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 sdi->driver is NULL, this is a virtual device. */
        if (!sdi->driver) {
-               sr_dbg("session: %s: sdi->driver was NULL, this seems to be "
+               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);
@@ -159,15 +170,10 @@ SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
 
        /* sdi->driver is non-NULL (i.e. we have a real device). */
        if (!sdi->driver->dev_open) {
-               sr_err("session: %s: sdi->driver->dev_open was NULL", __func__);
+               sr_err("%s: sdi->driver->dev_open was NULL", __func__);
                return SR_ERR_BUG;
        }
 
-       if ((ret = sdi->driver->dev_open((struct sr_dev_inst *)sdi)) != SR_OK) {
-               sr_err("session: %s: dev_open failed (%d)", __func__, ret);
-               return ret;
-       }
-
        session->devs = g_slist_append(session->devs, (gpointer)sdi);
 
        return SR_OK;
@@ -181,11 +187,11 @@ SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
 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;
@@ -196,49 +202,85 @@ 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;
 }
 
-static int sr_session_run_poll(void)
+/**
+ * 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_iteration(gboolean block)
 {
        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);
-                       }
+       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;
@@ -258,23 +300,24 @@ SR_API int sr_session_start(void)
        int ret;
 
        if (!session) {
-               sr_err("session: %s: session was NULL; a session must be "
+               sr_err("%s: session was NULL; a session must be "
                       "created before starting it.", __func__);
                return SR_ERR_BUG;
        }
 
        if (!session->devs) {
-               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;
        }
 
-       sr_info("session: starting");
+       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("session: %s: could not start an acquisition "
+                       sr_err("%s: could not start an acquisition "
                               "(%d)", __func__, ret);
                        break;
                }
@@ -293,19 +336,19 @@ SR_API int sr_session_start(void)
 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");
+       sr_info("Running.");
 
        /* Do we have real sources? */
        if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
@@ -314,45 +357,35 @@ SR_API int sr_session_run(void)
                        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.
- *
- * This function is deprecated and should not be used in new code, use
- * sr_session_stop() instead. The behaviour of this function is identical to
- * sr_session_stop().
- *
- * @return SR_OK upon success, SR_ERR_BUG if no session exists.
- */
-SR_API int sr_session_halt(void)
-{
-       return sr_session_stop();
-}
-
 /**
  * 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_API int sr_session_stop(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: stopping");
+       sr_info("Stopping.");
 
        for (l = session->devs; l; l = l->next) {
                sdi = l->data;
@@ -365,6 +398,33 @@ SR_API int sr_session_stop(void)
        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;
+}
+
 /**
  * Debug helper.
  *
@@ -377,38 +437,35 @@ static void datafeed_dump(const struct sr_datafeed_packet *packet)
 
        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_ANALOG");
+               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;
        }
 }
@@ -429,23 +486,23 @@ 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 (!sdi) {
-               sr_err("session: %s: sdi was NULL", __func__);
+               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;
-               cb(sdi, packet);
+               cb_struct = l->data;
+               cb_struct->cb(sdi, packet, cb_struct->cb_data);
        }
 
        return SR_OK;
@@ -470,7 +527,7 @@ static int _sr_session_source_add(GPollFD *pollfd, int timeout,
        GPollFD *new_pollfds;
 
        if (!cb) {
-               sr_err("session: %s: cb was NULL", __func__);
+               sr_err("%s: cb was NULL", __func__);
                return SR_ERR_ARG;
        }
 
@@ -479,14 +536,14 @@ static int _sr_session_source_add(GPollFD *pollfd, int timeout,
        new_pollfds = g_try_realloc(session->pollfds,
                        sizeof(GPollFD) * (session->num_sources + 1));
        if (!new_pollfds) {
-               sr_err("session: %s: new_pollfds malloc failed", __func__);
+               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("session: %s: new_sources malloc failed", __func__);
+               sr_err("%s: new_sources malloc failed", __func__);
                return SR_ERR_MALLOC;
        }
 
@@ -592,7 +649,7 @@ static int _sr_session_source_remove(gintptr poll_object)
        unsigned int old;
 
        if (!session->sources || !session->num_sources) {
-               sr_err("session: %s: sources was NULL", __func__);
+               sr_err("%s: sources was NULL", __func__);
                return SR_ERR_BUG;
        }
 
@@ -616,13 +673,13 @@ static int _sr_session_source_remove(gintptr poll_object)
 
        new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
        if (!new_pollfds && session->num_sources > 0) {
-               sr_err("session: %s: new_pollfds malloc failed", __func__);
+               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("session: %s: new_sources malloc failed", __func__);
+               sr_err("%s: new_sources malloc failed", __func__);
                return SR_ERR_MALLOC;
        }