node/lib/internal/child_process
Yagiz Nizipli a1074b8460
child_process: serialize advanced IPC messages natively
The `advanced` IPC serialization codec was implemented in JavaScript
(ChildProcessSerializer / ChildProcessDeserializer in
lib/internal/child_process/serialization.js). It allocated a wrapper
serializer/deserializer per message and crossed the JS/C++ boundary
several times for every message (writeHeader, writeValue, releaseBuffer,
readHeader, readValue and friends).

Move the codec into a native `ipc_serdes` binding that drives the V8
ValueSerializer/ValueDeserializer with a C++ delegate. The wire format
is preserved byte-for-byte: a big-endian uint32 length prefix followed
by the V8 payload, with ArrayBufferViews tagged as host objects so that
Node Buffers round-trip as Buffers rather than plain Uint8Arrays. The
JSON codec is left unchanged.

A cctest (test/cctest/test_node_ipc_serdes.cc) exercises the binding
directly, covering round-trips of primitives, objects, typed arrays and
Buffers (including the Buffer-vs-Uint8Array distinction) and asserting
the big-endian length-prefix framing.

Round-trip throughput
(benchmark/child_process/child-process-ipc-roundtrip):

  payload   before     after      change
  64 B      ~300k/s    ~800k/s    +166%
  1 KiB     ~272k/s    ~616k/s    +126%
  16 KiB    ~91k/s     ~120k/s    +32%
  64 KiB    ~30k/s     ~35k/s     +16%

The gain is largest for small messages, where per-message JavaScript
overhead dominated, and tapers for large messages, where the actual
serialization (already native) dominates.

Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com>
PR-URL: https://github.com/nodejs/node/pull/63933
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
2026-06-18 18:14:46 +00:00
..
serialization.js child_process: serialize advanced IPC messages natively 2026-06-18 18:14:46 +00:00