info is board_info now

[comedilib.git] / demo / ao_mmap.c

diff --git a/demo/ao_mmap.c b/demo/ao_mmap.c
index 1646c764b4dc270a91b25c88aeab47c094ae4949..f4b65d9aa5879849874f563b4aa95058043f21ed 100644 (file)
--- a/demo/ao_mmap.c
+++ b/demo/ao_mmap.c
@@ -76,6 +76,7 @@ int main(int argc, char *argv[])
        comedi_range *rng;
        int ret;
        int size;
+       int num_samples;
        sampl_t *map;
        /* peak-to-peak amplitude, in DAC units (i.e., 0-4095) */
        double amplitude;
@@ -148,36 +149,45 @@ int main(int argc, char *argv[])
                perror("mmap");
                exit(1);
        }
-       write_waveform(map, size / sizeof(sampl_t), amplitude, offset, maxdata);
+       num_samples = size / sizeof(sampl_t);
+       write_waveform(map, num_samples, amplitude, offset, maxdata);
        if(msync(map, size, MS_SYNC) < 0)
        {
                perror("msync");
                exit(1);
        }
-       if(comedi_mark_buffer_written(dev, subdevice, size) < 0)
+       printf("marking %i samples as written\n", num_samples);
+       ret = comedi_mark_buffer_written(dev, subdevice, size);
+       if(ret < 0)
        {
                comedi_perror("comedi_mark_buffer_written");
                exit(1);
        }
        ret = comedi_internal_trigger(dev, subdevice, 0);
        if(ret<0){
-               comedi_perror("comedi_internal_trigger\n");
+               comedi_perror("comedi_internal_trigger");
                exit(1);
        }
-       while(1){
+       while(1)
+       {
                int bytes_marked = comedi_get_buffer_contents(dev,subdevice);
-               if(bytes_marked < 1)
+               if(bytes_marked < 0)
                {
                        comedi_perror("comedi_get_buffer_contents");
                        exit(1);
                }
                int bytes_unmarked = size - bytes_marked;
-               // this keeps comedi from reporting a buffer underrun
-               if(comedi_mark_buffer_written(dev, subdevice, bytes_unmarked) < 0)
+               if(bytes_unmarked > 0)
                {
-                       comedi_perror("comedi_mark_buffer_written");
-                       exit(1);
-               }
+                       // this keeps comedi from reporting a buffer underrun
+                       if(comedi_mark_buffer_written(dev, subdevice, bytes_unmarked) < 0)
+                       {
+                               comedi_perror("comedi_mark_buffer_written");
+                               exit(1);
+                       }
+                       printf("marked %i more samples as written\n", bytes_unmarked / sizeof(sampl_t));
+               }else
+                       usleep(10000);
        }
        return 0;
 }