Demo: Obery samplerate and fix race condition.

diff --git a/hardware/demo/demo.c b/hardware/demo/demo.c
index ec8a74bc3f5c225a64fe55e5e5c8e77ef270804f..1b16ee6a050db8bf62605c2758f5d6c6dcb378c8 100644 (file)
--- a/hardware/demo/demo.c
+++ b/hardware/demo/demo.c
@@ -49,7 +49,6 @@ struct databag {
        uint8_t thread_running;
        uint64_t samples_counter;
        int device_index;
-       int loop_sleep;
        gpointer session_device_id;
        GTimer *timer;
 };
@@ -81,7 +80,7 @@ static uint8_t genmode_default[] = {
 
 /* List of struct sigrok_device_instance, maintained by opendev()/closedev(). */
 static GSList *device_instances = NULL;
-static uint64_t cur_samplerate = 0;
+static uint64_t cur_samplerate = KHZ(200);
 static uint64_t limit_samples = 0;
 static uint64_t limit_msec = 0;
 static int default_genmode = GENMODE_DEFAULT;
@@ -239,60 +238,83 @@ static void thread_func(void *data)
        uint8_t buf[BUFSIZE];
        uint64_t nb_to_send = 0;
        int bytes_written;
-       unsigned int msec_elapsed;
+
+       double time_cur, time_last, time_diff;
+
+       time_last = g_timer_elapsed(mydata->timer, NULL);
 
        while (thread_running) {
+               /* Rate control */
+               time_cur = g_timer_elapsed(mydata->timer, NULL);
+
+               time_diff = time_cur - time_last;
+               time_last = time_cur;
+
+               nb_to_send = cur_samplerate * time_diff;
+
                if (limit_samples)
-                       nb_to_send = limit_samples - mydata->samples_counter;
-               else
-                       nb_to_send = BUFSIZE;  /* Continuous mode */
-
-               if (limit_msec) {
-                       msec_elapsed = g_timer_elapsed(mydata->timer, NULL) * 1000;
-                       if (msec_elapsed > limit_msec)
-                               nb_to_send = 0;
+                       nb_to_send = MIN(nb_to_send,
+                                       limit_samples - mydata->samples_counter);
+
+               /* Make sure we don't overflow. */
+               nb_to_send = MIN(nb_to_send, BUFSIZE);
+
+               if (nb_to_send) {
+                       samples_generator(buf, nb_to_send, data);
+                       mydata->samples_counter += nb_to_send;
+
+                       g_io_channel_write_chars(channels[1], (gchar *)&buf,
+                                       nb_to_send, (gsize *)&bytes_written, NULL);
                }
 
-               if (nb_to_send == 0) {
+               /* Check if we're done. */
+               if ((limit_msec && time_cur * 1000 > limit_msec) ||
+                   (limit_samples && mydata->samples_counter >= limit_samples))
+               {
                        close(mydata->pipe_fds[1]);
                        thread_running = 0;
-                       hw_stop_acquisition(mydata->device_index,
-                                           mydata->session_device_id);
-               } else if (nb_to_send > BUFSIZE) {
-                       nb_to_send = BUFSIZE;
                }
 
-               samples_generator(buf, nb_to_send, data);
-               mydata->samples_counter += nb_to_send;
-
-               g_io_channel_write_chars(channels[1], (gchar *)&buf,
-                               nb_to_send, (gsize *)&bytes_written, NULL);
-
-               g_usleep(mydata->loop_sleep);
+               g_usleep(10);
        }
 }
 
 /* Callback handling data */
 static int receive_data(int fd, int revents, void *user_data)
 {
-       struct datafeed_packet packet;
-       char c[BUFSIZE];
-       uint64_t z;
-
-       /* Avoid compiler warnings. */
-       fd = fd;
-       revents = revents;
+struct datafeed_packet packet;
+char c[BUFSIZE];
+uint64_t z;
+
+/* Avoid compiler warnings. */
+fd = fd;
+revents = revents;
+
+       do {
+               g_io_channel_read_chars(channels[0],
+                                       (gchar *)&c, BUFSIZE, &z, NULL);
+
+               if (z > 0) {
+                       packet.type = DF_LOGIC;
+                       packet.length = z;
+                       packet.unitsize = 1;
+                       packet.payload = c;
+                       session_bus(user_data, &packet);
+               }
+       } while (z > 0);
 
-       g_io_channel_read_chars(channels[0], (gchar *)&c, BUFSIZE,
-                               (gsize *)&z, NULL);
+       if (!thread_running && z <= 0)
+       {
+               /* Make sure we don't receive more packets */
+               g_io_channel_close(channels[0]);
 
-       if (z > 0) {
-               packet.type = DF_LOGIC;
-               packet.length = z;
-               packet.unitsize = 1;
-               packet.payload = c;
+               /* Send last packet. */
+               packet.type = DF_END;
                session_bus(user_data, &packet);
+
+               return FALSE;
        }
+
        return TRUE;
 }
 
@@ -310,7 +332,6 @@ static int hw_start_acquisition(int device_index, gpointer session_device_id)
        mydata->session_device_id = session_device_id;
        mydata->device_index = device_index;
        mydata->samples_counter = 0;
-       mydata->loop_sleep = 100000;
 
        if (pipe(mydata->pipe_fds))
                return SIGROK_ERR;
@@ -331,8 +352,7 @@ static int hw_start_acquisition(int device_index, gpointer session_device_id)
 
        /* Run the demo thread. */
        g_thread_init(NULL);
-       if (limit_msec)
-               mydata->timer = g_timer_new();
+       mydata->timer = g_timer_new();
        thread_running = 1;
        my_thread =
            g_thread_create((GThreadFunc)thread_func, mydata, TRUE, NULL);
@@ -362,14 +382,12 @@ static int hw_start_acquisition(int device_index, gpointer session_device_id)
 
 static void hw_stop_acquisition(int device_index, gpointer session_device_id)
 {
-       struct datafeed_packet packet;
-
        /* Avoid compiler warnings. */
        device_index = device_index;
+       session_device_id = session_device_id;
 
-       /* Send last packet. */
-       packet.type = DF_END;
-       session_bus(session_device_id, &packet);
+       /* Stop generate thread. */
+       thread_running = 0;
 }
 
 struct device_plugin demo_plugin_info = {