ouroboros/src/lib/tests/shm_rbuff_test.c, branch master

lib: Replace rdrbuff with a proper slab allocator

2026-01-26T06:50:33+00:00

This is a first step towards the Secure Shared Memory (SSM) infrastructure for Ouroboros, which will allow proper resource separation for non-privileged processes. This replaces the rdrbuff (random-deletion ring buffer) PoC allocator with a sharded slab allocator for the packet buffer pool to avoid the head-of-line blocking behaviour of the rdrb and reduce lock contention in multi-process scenarios. Each size class contains multiple independent shards, allowing parallel allocations without blocking. - Configurable shard count per size class (default: 4, set via SSM_POOL_SHARDS in CMake). The configured number of blocks are spread over the number of shards. As an example: SSM_POOL_512_BLOCKS = 768 blocks total These 768 blocks are shared among 4 shards (not 768 × 4 = 3072 blocks) - Lazy block distribution: all blocks initially reside in shard 0 and naturally migrate to process-local shards upon first allocation and subsequent free operations - Fallback with work stealing: processes attempt allocation from their local shard (pid % SSM_POOL_SHARDS) first, then steal from other shards if local is exhausted, eliminating fragmentation while maintaining low contention - Round-robin condvar signaling: blocking allocations cycle through all shard condition variables to ensure fairness - Blocks freed to allocator's shard: uses allocator_pid to determine target shard, enabling natural load balancing as process allocation patterns stabilize over time Maintains existing robust mutex semantics including EOWNERDEAD handling for dead process recovery. Internal structures exposed in ssm.h for testing purposes. Adds some tests (pool_test, pool_sharding_test.c. etc) verifying lazy distribution, migration, fallback stealing, and multiprocess behavior. Updates the ring buffer (rbuff) to use relaxed/acquire/release ordering on atomic indices. The ring buffer requires the (robust) mutex to ensure cross-structure synchronization between pool buffer writes and ring buffer index publication. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update licenses to 2024

2024-01-13T09:20:14+00:00

Slow but steady. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2023

2023-02-13T20:10:10+00:00

2022 was a rather slow year... Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2022

2022-04-03T16:01:02+00:00

Growing pains. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update email addresses

2021-01-03T10:57:05+00:00

The ugent email addresses are shut down, updated to Ouroboros mail addresses. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2021

2021-01-03T10:56:28+00:00

Happy New Year, Ouroboros! Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Fix shm_rbuff test

2020-02-16T17:25:17+00:00

The rbuff_destroy function asserts that we do not try to destroy an rbuff that still contains packets. The test now empties the rbuff before destroying it. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

2020-01-02T14:07:36+00:00

Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Add tests for the shm_rbuff

2019-06-21T16:47:30+00:00

This adds some tests for the shm_rbuff after some reports that the queue length would be erroneously reported as 0 when the rbuff was full. The test passes for the reported case. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders