Shared-Memory

Same-host ROS 2 Jazzy latency for 1 KB to 4 MB messages: Fast DDS UDP, SHM and data-sharing vs Cyclone DDS with iceoryx

ROS 2 Shared Memory, Measured: Fast DDS SHM and Data-Sharing vs Cyclone DDS + iceoryx

I benchmarked same-host ROS 2 Jazzy pub/sub latency for 1 KB, 1 MB and 4 MB messages across six transport setups. Cyclone DDS + iceoryx with loaned messages moved 4 MB at an 83 µs median. Getting there took two settings nobody turns on by default, and the Fast DDS defaults fall over above 512 KB.

Cross-process zero-copy NVMM IPC on Jetson — dma-buf fd passing, NvBufSurfaceImport, lock-free pool

Cross-Process Zero-Copy on Jetson: dma-buf fds, NvBufSurfaceImport, and a Cache-Line-Padded Pool

Two processes on a Jetson, one camera frame in NVMM (GPU memory), no copies. The kernel does the heavy lifting via dma-buf fds; SCM_RIGHTS carries the fd across the process boundary; NvBufSurfaceImport reconstructs the surface on the consumer side; a cache-line-padded ring of atomic ref-counts keeps fan-out coherent without locks. With benchmark numbers and a Godbolt-runnable demo of the SCM_RIGHTS pattern.

Anatomy of Four GStreamer Shared Memory Bugs

Four bugs in GStreamer’s shmsink/shmsrc elements — a race condition, a use-after-free, a wrong-pointer dereference, and a page alignment mismatch. What they have in common, how to find them, and what they teach about writing correct GStreamer elements.

Why GStreamer shmsink Always Exits with Code 1

Fixing a GStreamer Bug: Why shmsink Always Exits with Code 1

A 2-line fix for a race condition in GStreamer’s shmsink that causes every pipeline using shared memory to exit with an error. How I found it, proved it, and verified the fix with sanitizers.