ouroboros/src/lib/shm_flow_set.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

irmd: Revise IRMd internals

2024-02-19T10:49:07+00:00

This is a full revision of the IRMd internal implementation. The registry is now a proper subcomponent managing its own internal lock (a single mutex). Some tests are added for the registry and its data structures. Some macros for tests are added in . Flow allocation is now more symmetric between the client side (alloc) and server size (accept). Each will create a flow in pending state (ALLOC_PENDING/ACCEPT_PENDING) that is potentially fulfilled by an IPCP using respond_alloc and respond_accept primitives. Deallocation is split in flow_dealloc (application side) and ipcp_flow_dealloc (IPCP side) to get the flow in DEALLOC_PENDING and DEALLOCATED state. Cleanup of failed flow allocation is now properly handled instead of relying on the sanitizer thread. The new sanitizer only needs to monitor crashed processes. On shutdown, the IRMd will now detect hanging processes and SIGKILL them and clean up their fuse mountpoints if needed. A lot of other things have been cleaned up and shuffled around a bit. 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

lib: Wrap pthread_cond_timedwait for NULL abstime

2023-10-25T07:53:27+00:00

We often have the pattern where we NULL-check abstime for pthread_cond_timedwait to call pthread_cond_wait if it is. Added a __timedwait function to wrap this. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Rename portevent to flowevent

2023-09-20T16:51:19+00:00

Doesn't make any sense to call it a port event... Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Fix lengths of shared memory objects

2023-08-23T11:09:10+00:00

Seems like all shared memory objects were truncated to a size that came up a byte short. 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

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

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

lib: Fix fqueue_next handling of deallocated flows

2022-04-01T06:09:22+00:00

If a flow was deallocated while there were still unprocessed events in an fqueue, it would cause a SEGV in fqueue_next because it was not checking the validity of the returned flow descriptor. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Use struct portevent internally

2022-03-30T13:12:25+00:00

The fqueues were relying on the fact that the portevent were two integers. This cleans that up a bit. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders