Update burn_source to version 1, that adds cancel() function.

demo/iso.c

@@ -170,7 +170,7 @@ int main(int argc, char **argv)
         return 1;
     }
     
-    while (burn_src->read(burn_src, buf, 2048) == 2048) {
+    while (burn_src->read_xt(burn_src, buf, 2048) == 2048) {
         fwrite(buf, 1, 2048, fd);
     }
     fclose(fd);

demo/iso_modify.c

@@ -119,7 +119,7 @@ int main(int argc, char **argv)
         return 1;
     }
     
-    while (burn_src->read(burn_src, buf, 2048) == 2048) {
+    while (burn_src->read_xt(burn_src, buf, 2048) == 2048) {
         fwrite(buf, 1, 2048, fd);
     }
     fclose(fd);

demo/iso_ms.c

@@ -122,7 +122,7 @@ int main(int argc, char **argv)
         return 1;
     }
     
-    while (burn_src->read(burn_src, buf, 2048) == 2048) {
+    while (burn_src->read_xt(burn_src, buf, 2048) == 2048) {
         fwrite(buf, 1, 2048, fd);
     }
     fclose(fd);

src/buffer.c

@@ -253,6 +253,13 @@ void iso_ring_buffer_writer_close(IsoRingBuffer *buf, int error)
 void iso_ring_buffer_reader_close(IsoRingBuffer *buf, int error)
 {
     pthread_mutex_lock(&buf->mutex);
+    
+    if (buf->rend) {
+        /* reader already closed */
+        pthread_mutex_unlock(&buf->mutex);
+        return;
+    }
+
     buf->rend = error ? 2 : 1;
 
     /* ensure no writer is waiting */

src/ecma119.c

@@ -1103,6 +1103,22 @@ static void bs_free_data(struct burn_source *bs)
     ecma119_image_free(target);
 }
 
+int bs_cancel(struct burn_source *bs)
+{
+    Ecma119Image *target = (Ecma119Image*)bs->data;
+    
+    iso_msg_debug(target->image->id, "Reader thread being cancelled");
+
+    /* forces writer to stop if it is still running */
+    iso_ring_buffer_reader_close(target->buffer, ISO_CANCELED);
+
+    /* wait until writer thread finishes */
+    pthread_join(target->wthread, NULL);
+
+    iso_msg_debug(target->image->id, "Writer thread joined");
+    return ISO_SUCCESS;
+}
+
 static
 int bs_set_size(struct burn_source *bs, off_t size)
 {
@@ -1140,10 +1156,13 @@ int iso_image_create_burn_source(IsoImage *image, Ecma119WriteOpts *opts,
     }
 
     source->refcount = 1;
-    source->read = bs_read;
+    source->version = 1;
+    source->read = NULL;
     source->get_size = bs_get_size;
     source->set_size = bs_set_size;
     source->free_data = bs_free_data;
+    source->read_xt = bs_read;
+    source->cancel = bs_cancel;
     source->data = target;
 
     *burn_src = source;