+static void wng_post_select(struct sched *s, struct task *t)
+{
+ struct writer_node_group *g = container_of(t, struct writer_node_group, task);
+ int i;
+ size_t min_written = 0, max_written = 0;
+
+ FOR_EACH_WRITER_NODE(i, g) {
+ struct writer_node *wn = &g->writer_nodes[i];
+ struct writer *w = writers + wn->writer_num;
+ t->error = w->post_select(s, wn);
+ if (t->error < 0)
+ return;
+ if (!i)
+ min_written = wn->written;
+ else
+ min_written = PARA_MIN(min_written, wn->written);
+ max_written = PARA_MAX(max_written, wn->written);
+ }
+ g->last_written = max_written;
+ //PARA_INFO_LOG("loaded: %zd, min_written: %zd bytes\n", *g->loaded, min_written);
+ if (min_written) {
+ *g->loaded -= min_written;
+ FOR_EACH_WRITER_NODE(i, g)
+ g->writer_nodes[i].written -= min_written;
+ }
+ if (!*g->loaded && *g->input_error) {
+ t->error = *g->input_error;
+ return;
+ }
+ if (*g->loaded && min_written) {
+// PARA_INFO_LOG("moving %zd bytes\n", *g->loaded);
+ memmove(*g->bufp, *g->bufp + min_written, *g->loaded);
+ }
+}
+
+/**
+ * call the open function of each writer in the group
+ *
+ * \param g the writer node group
+ *
+ * \return If at least one open function returned an error, all successful
+ * writer notes get closed and this error value is returned. Upon success, a
+ * task associated with \a g is registered to the scheduler and the function
+ * returns a positive value.
+ * */