void h2o_http2_scheduler_rebind(h2o_http2_scheduler_openref_t *ref, h2o_http2_scheduler_node_t *new_parent, uint16_t weight,
int exclusive)
{
assert(h2o_http2_scheduler_is_open(ref));
assert(&ref->node != new_parent);
assert(1 <= weight);
assert(weight <= 257);
/* do nothing if there'd be no change at all */
if (ref->node._parent == new_parent && ref->weight == weight && !exclusive)
return;
ref->weight = weight;
{ /* if new_parent is dependent to ref, make new_parent a sibling of ref before applying the final transition (see draft-16
5.3.3) */
h2o_http2_scheduler_node_t *t;
for (t = new_parent; t->_parent != NULL; t = t->_parent) {
if (t->_parent == &ref->node) {
/* quoting the spec: "The moved dependency retains its weight." */
h2o_http2_scheduler_openref_t *new_parent_ref = (void *)new_parent;
do_rebind(new_parent_ref, ref->node._parent, 0);
break;
}
}
}
do_rebind(ref, new_parent, exclusive);
}
void h2o_http2_conn_unregister_stream(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream)
{
khiter_t iter = kh_get(h2o_http2_stream_t, conn->streams, stream->stream_id);
assert(iter != kh_end(conn->streams));
kh_del(h2o_http2_stream_t, conn->streams, iter);
assert(h2o_http2_scheduler_is_open(&stream->_refs.scheduler));
h2o_http2_scheduler_close(&stream->_refs.scheduler);
switch (stream->state) {
case H2O_HTTP2_STREAM_STATE_IDLE:
case H2O_HTTP2_STREAM_STATE_RECV_HEADERS:
case H2O_HTTP2_STREAM_STATE_RECV_BODY:
assert(!h2o_linklist_is_linked(&stream->_refs.link));
break;
case H2O_HTTP2_STREAM_STATE_REQ_PENDING:
assert(h2o_linklist_is_linked(&stream->_refs.link));
h2o_linklist_unlink(&stream->_refs.link);
break;
case H2O_HTTP2_STREAM_STATE_SEND_HEADERS:
case H2O_HTTP2_STREAM_STATE_SEND_BODY:
case H2O_HTTP2_STREAM_STATE_END_STREAM:
if (h2o_linklist_is_linked(&stream->_refs.link))
h2o_linklist_unlink(&stream->_refs.link);
break;
}
if (stream->state != H2O_HTTP2_STREAM_STATE_END_STREAM)
h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_END_STREAM);
if (conn->state < H2O_HTTP2_CONN_STATE_IS_CLOSING) {
run_pending_requests(conn);
update_idle_timeout(conn);
}
}
void h2o_http2_scheduler_close(h2o_http2_scheduler_openref_t *ref)
{
assert(h2o_http2_scheduler_is_open(ref));
/* move dependents to parent */
if (!h2o_linklist_is_empty(&ref->node._all_refs)) {
/* proportionally distribute the weight to the children (draft-16 5.3.4) */
uint32_t total_weight = 0, factor;
h2o_linklist_t *link;
for (link = ref->node._all_refs.next; link != &ref->node._all_refs; link = link->next) {
h2o_http2_scheduler_openref_t *child_ref = H2O_STRUCT_FROM_MEMBER(h2o_http2_scheduler_openref_t, _all_link, link);
total_weight += child_ref->weight;
}
assert(total_weight != 0);
factor = ((uint32_t)ref->weight * 65536 + total_weight / 2) / total_weight;
do {
h2o_http2_scheduler_openref_t *child_ref =
H2O_STRUCT_FROM_MEMBER(h2o_http2_scheduler_openref_t, _all_link, ref->node._all_refs.next);
uint16_t weight = (child_ref->weight * factor / 32768 + 1) / 2;
if (weight < 1)
weight = 1;
else if (weight > 256)
weight = 256;
h2o_http2_scheduler_rebind(child_ref, ref->node._parent, weight, 0);
} while (!h2o_linklist_is_empty(&ref->node._all_refs));
}
free(ref->node._queue);
ref->node._queue = NULL;
/* detach self */
h2o_linklist_unlink(&ref->_all_link);
if (ref->_self_is_active) {
assert(ref->_active_cnt == 1);
queue_unset(&ref->_queue_node);
decr_active_cnt(ref->node._parent);
} else {
assert(ref->_active_cnt == 0);
}
}