Xbox input send queue #

NetSendQueue coalesces only adjacent, same-session input packets waiting for DataWriter::StoreAsync. The in-flight write is unchanged. Simulation and the configured input frequency are unchanged; the paired build remains at 30 Hz until a separate device trial establishes a benefit at 60 Hz.

Every frame from both packets survives in the merged history. Overlapping masks must agree, ranges cannot move backwards or leave a gap, and the union cannot exceed the receiver's existing 20-frame limit (NET_REDUNDANCY * 2). Newest acknowledgement, simulation-frame, lead, timestamp and echo fields remain verbatim. Hashes, controls, unknown extensions, different session origins and malformed/unrecognized packets remain FIFO barriers. Queue capacity stays 32; a full queue may accept an input only by safely merging its tail. This does not change existing socket-error recovery or retry semantics.

xbox/runtime/tests/net_send_queue_contract.cpp checks parsing boundaries, both JSON field orders, conflicting overlaps, gaps, session changes, barriers, maximum packet size, queue capacity, and complete frame preservation through a 100-packet burst. It passes with C++17, AddressSanitizer and UndefinedBehaviorSanitizer. The Windows native preflight also compiles and runs it.

A deterministic 30-second simulation with 60 Hz input and a 25 ms serialized writer produced these results:

These are synthetic results. They do not establish Xbox RTT, game FPS, or improved performance on the current LAN. Native package 1.0.0.44 passed Windows preflight, GDK and UWP builds (AppVeyor 1.0.462) and was installed with shared game v169, photographic assets and the LAN relay verified. A matched device profile is still required before raising the configured 30 Hz send frequency.