Robert Schmidt
b15d394212
Because it is SPSC, atomic variables are enough to synchronize the two
threads. Concretely put() is modified to ensure that read_idx is
"acquired" so that the read index has been written, including memory, by
the other thread. "Release" ensures that the write operation (including
the memory to the buffer) is written before it is visible to the other
thread in get() (which in turn "acquires" it). For more information, see
also [1].
The rest of the library has been simplified to work only with put() and
get(), reducing total code and the surface for possible bugs.
This (and the previous) version has been tested with the
threadSanitizer:
TSAN_OPTIONS=halt_on_error=1 ./common/utils/ds/tests/test_spsc_q_perf
On my machine, using Google Benchmark, I measure a considerable 5x speed
improvement:
$ /tmp/benchmark/tools/compare.py benchmarks pthread.json atomic.json
Comparing pthread.json to atomic.json
Benchmark Time CPU Time Old Time New CPU Old CPU New
--------------------------------------------------------------------------------------------------------------
BM_spsc_q/10 -0.8201 -0.0740 266779912 47989020 52387 48512
BM_spsc_q/16 -0.8301 -0.0520 249656592 42428540 51462 48784
BM_spsc_q/32 -0.8003 -0.0841 230248798 45972155 53841 49311
BM_spsc_q/64 -0.7995 -0.0506 210429791 42199674 50690 48124
BM_spsc_q/128 -0.7930 -0.1101 205212273 42483155 52745 46936
BM_spsc_q/160 -0.7880 -0.1663 216644738 45938247 53400 44518
OVERALL_GEOMEAN -0.8057 -0.0904 0 0 0 0
[1] https://en.cppreference.com/w/c/atomic/memory_order.html
Assisted-By: Claude:claude-sonnet-4-6
Signed-off-by: Robert Schmidt <robert.schmidt@openairinterface.org>
OpenAirInterface License
The source code is distributed under CSSL v1.0. Some files, such as for orchestration, are distributed under MIT license(MIT.txt). Documentation is distributed under Creative Commons Attribution 4.0 International license.
All the files without an explicit copyright header have an implicit "Copyright of OpenAirInterface Authors".
Please see NOTICE for other licenses which are used in the software.
In the past OAI source code has been re-licensed sometimes, here is the history:
- CSSL v1.0 starting tag 2026.w14
- OAI Public License v1.1 starting tag v1.0 till
af4b0d53 - OAI Public License v1.0: starting tag v.04 till v1.0
- GPL 3: starting tag v.0 till v.04 (only initial implementation of 4G)
Where to Start
- General overview of documentation
- The implemented features
- System Requirements for Using OAI Stack
- How to build
- How to run the modems
Not all information is available in a central place, and information for specific sub-systems might be available in the corresponding sub-directories. To find all READMEs, this command might be handy:
find . -iname "readme*"
RAN repository structure
The OpenAirInterface (OAI) software is composed of the following parts:
openairinterface5g
├── charts
├── ci-scripts : Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
├── CMakeLists.txt : Top-level CMakeLists.txt for building
├── cmake_targets : Build utilities to compile (simulation, emulation and real-time platforms), and generated build files.
├── common : Some common OAI utilities, some other tools can be found at openair2/UTILS.
├── doc : Documentation
├── docker : Dockerfiles to build for Ubuntu and RHEL
├── executables : Top-level executable source files (gNB, eNB, ...)
├── maketags : Script to generate emacs tags.
├── nfapi : (n)FAPI code for MAC-PHY interface
├── openair1 : Layer 1 (3GPP LTE Rel-10/12 PHY, NR Rel-15 PHY)
├── openair2 : Layer 2 (3GPP LTE Rel-10 MAC/RLC/PDCP/RRC/X2AP, LTE Rel-14 M2AP, NR Rel-15+ MAC/RLC/PDCP/SDAP/RRC/X2AP/F1AP/E1AP), E2AP
├── openair3 : Layer 3 (3GPP LTE Rel-10 S1AP/GTP, NR Rel-15 NGAP/GTP)
├── openshift : OpenShift helm charts for some deployment options of OAI
├── radio : Drivers for various radios such as USRP, AW2S, RFsim, 7.2 FHI, ...
├── targets : Some configuration files; only historical relevance, and might be deleted in the future
└── tools : Tools for use by the developers/ci machines: code analysis and formatting
How to get support from the OAI Community
You can ask your question on the mailing lists.
Your email should contain below information:
- A clear subject in your email.
- For all the queries there should be [Query] in the subject of the email and for problems there should be [Problem].
- In case of a problem, add a small description.
- Do not share any photos unless you want to share a diagram.
- OAI gNB/DU/CU/CU-CP/CU-UP configuration file in
.confformat only. - Logs of OAI gNB/DU/CU/CU-CP/CU-UP in
.logor.txtformat only. - In case your question is related to performance, include a small description of the machine (Operating System, Kernel version, CPU, RAM and networking card) and diagram of your testing environment.
- Known/open issues are present on GitLab, so keep checking.
Always remember a structured email will help us understand your issues quickly.