static void maybe_start_some_streams(
grpc_chttp2_transport_global *transport_global) {
grpc_chttp2_stream_global *stream_global;
/* start streams where we have free grpc_chttp2_stream ids and free
* concurrency */
while (transport_global->next_stream_id <= MAX_CLIENT_STREAM_ID &&
transport_global->concurrent_stream_count <
transport_global
->settings[GRPC_PEER_SETTINGS]
[GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS] &&
grpc_chttp2_list_pop_waiting_for_concurrency(transport_global,
&stream_global)) {
GRPC_CHTTP2_IF_TRACING(gpr_log(
GPR_DEBUG, "HTTP:%s: Allocating new grpc_chttp2_stream %p to id %d",
transport_global->is_client ? "CLI" : "SVR", stream_global,
transport_global->next_stream_id));
GPR_ASSERT(stream_global->id == 0);
stream_global->id = transport_global->next_stream_id;
transport_global->next_stream_id += 2;
if (transport_global->next_stream_id >= MAX_CLIENT_STREAM_ID) {
connectivity_state_set(transport_global, GRPC_CHANNEL_TRANSIENT_FAILURE,
"no_more_stream_ids");
}
stream_global->outgoing_window =
transport_global->settings[GRPC_PEER_SETTINGS]
[GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
stream_global->incoming_window =
transport_global->settings[GRPC_SENT_SETTINGS]
[GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
stream_global->max_recv_bytes =
GPR_MAX(stream_global->incoming_window, stream_global->max_recv_bytes);
grpc_chttp2_stream_map_add(
&TRANSPORT_FROM_GLOBAL(transport_global)->new_stream_map,
stream_global->id, STREAM_FROM_GLOBAL(stream_global));
stream_global->in_stream_map = 1;
transport_global->concurrent_stream_count++;
grpc_chttp2_list_add_incoming_window_updated(transport_global,
stream_global);
grpc_chttp2_list_add_writable_stream(transport_global, stream_global);
}
/* cancel out streams that will never be started */
while (transport_global->next_stream_id >= MAX_CLIENT_STREAM_ID &&
grpc_chttp2_list_pop_waiting_for_concurrency(transport_global,
&stream_global)) {
cancel_from_api(transport_global, stream_global, GRPC_STATUS_UNAVAILABLE);
}
}
int grpc_chttp2_unlocking_check_writes(
grpc_chttp2_transport_global *transport_global,
grpc_chttp2_transport_writing *transport_writing) {
grpc_chttp2_stream_global *stream_global;
grpc_chttp2_stream_writing *stream_writing;
grpc_chttp2_stream_global *first_reinserted_stream = NULL;
gpr_uint32 window_delta;
/* simple writes are queued to qbuf, and flushed here */
gpr_slice_buffer_swap(&transport_global->qbuf, &transport_writing->outbuf);
GPR_ASSERT(transport_global->qbuf.count == 0);
if (transport_global->dirtied_local_settings &&
!transport_global->sent_local_settings) {
gpr_slice_buffer_add(
&transport_writing->outbuf,
grpc_chttp2_settings_create(
transport_global->settings[GRPC_SENT_SETTINGS],
transport_global->settings[GRPC_LOCAL_SETTINGS],
transport_global->force_send_settings, GRPC_CHTTP2_NUM_SETTINGS));
transport_global->force_send_settings = 0;
transport_global->dirtied_local_settings = 0;
transport_global->sent_local_settings = 1;
}
/* for each grpc_chttp2_stream that's become writable, frame it's data
(according to available window sizes) and add to the output buffer */
while (grpc_chttp2_list_pop_writable_stream(
transport_global, transport_writing, &stream_global, &stream_writing)) {
if (stream_global == first_reinserted_stream) {
/* prevent infinite loop */
grpc_chttp2_list_add_first_writable_stream(transport_global,
stream_global);
break;
}
stream_writing->id = stream_global->id;
stream_writing->send_closed = GRPC_DONT_SEND_CLOSED;
if (stream_global->outgoing_sopb) {
window_delta =
grpc_chttp2_preencode(stream_global->outgoing_sopb->ops,
&stream_global->outgoing_sopb->nops,
GPR_MIN(transport_global->outgoing_window,
stream_global->outgoing_window),
&stream_writing->sopb);
GRPC_CHTTP2_FLOWCTL_TRACE_TRANSPORT(
"write", transport_global, outgoing_window, -(gpr_int64)window_delta);
GRPC_CHTTP2_FLOWCTL_TRACE_STREAM("write", transport_global, stream_global,
outgoing_window,
-(gpr_int64)window_delta);
transport_global->outgoing_window -= window_delta;
stream_global->outgoing_window -= window_delta;
if (stream_global->write_state == GRPC_WRITE_STATE_QUEUED_CLOSE &&
stream_global->outgoing_sopb->nops == 0) {
if (!transport_global->is_client && !stream_global->read_closed) {
stream_writing->send_closed = GRPC_SEND_CLOSED_WITH_RST_STREAM;
} else {
stream_writing->send_closed = GRPC_SEND_CLOSED;
}
}
if (stream_global->outgoing_window > 0 &&
stream_global->outgoing_sopb->nops != 0) {
grpc_chttp2_list_add_writable_stream(transport_global, stream_global);
if (first_reinserted_stream == NULL &&
transport_global->outgoing_window == 0) {
first_reinserted_stream = stream_global;
}
}
}
if (!stream_global->read_closed && stream_global->unannounced_incoming_window > 0) {
stream_writing->announce_window = stream_global->unannounced_incoming_window;
GRPC_CHTTP2_FLOWCTL_TRACE_STREAM("write", transport_global, stream_global,
incoming_window, stream_global->unannounced_incoming_window);
GRPC_CHTTP2_FLOWCTL_TRACE_STREAM("write", transport_global, stream_global,
unannounced_incoming_window, -(gpr_int64)stream_global->unannounced_incoming_window);
stream_global->incoming_window += stream_global->unannounced_incoming_window;
stream_global->unannounced_incoming_window = 0;
grpc_chttp2_list_add_incoming_window_updated(transport_global,
stream_global);
stream_global->writing_now |= GRPC_CHTTP2_WRITING_WINDOW;
}
if (stream_writing->sopb.nops > 0 ||
stream_writing->send_closed != GRPC_DONT_SEND_CLOSED) {
stream_global->writing_now |= GRPC_CHTTP2_WRITING_DATA;
}
if (stream_global->writing_now != 0) {
grpc_chttp2_list_add_writing_stream(transport_writing, stream_writing);
}
}
/* if the grpc_chttp2_transport is ready to send a window update, do so here
also; 3/4 is a magic number that will likely get tuned soon */
if (transport_global->incoming_window <
transport_global->connection_window_target * 3 / 4) {
window_delta = transport_global->connection_window_target -
transport_global->incoming_window;
gpr_slice_buffer_add(&transport_writing->outbuf,
grpc_chttp2_window_update_create(0, window_delta));
GRPC_CHTTP2_FLOWCTL_TRACE_TRANSPORT("write", transport_global,
incoming_window, window_delta);
transport_global->incoming_window += window_delta;
}
return transport_writing->outbuf.count > 0 ||
grpc_chttp2_list_have_writing_streams(transport_writing);
}
