stdatomic.h is a C++23 feature [1]. Thus, "older" compilers such as
gcc-11 (default in Ubuntu 22) do not know this, and can therefore not
correctly compile spsc_q. Fix this by alternatively including atomic for
C++.
Fixes errors such as
stdatomic.h:40:9: error: ‘_Atomic’ does not name a type
[1] https://en.cppreference.com/cpp/header/stdatomic.h
Signed-off-by: Robert Schmidt <robert.schmidt@openairinterface.org>
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>
This data structure is designed to support the use cases of the L1,
i.e., provide a queue which can be quickly used to order L1 jobs in FIFO
order with simple iteration of jobs to treat. It is a Single-Consumer
Single-Producer queue library.
Signed-off-by: Robert Schmidt <robert.schmidt@openairinterface.org>
- all RAN code, CI code, configuration files, dockerfiles, in CSSL v1.0
- all deployment code (openshift, charts, ancillary files like shell
scripts), in MIT
- documentation in CC-BY-4.0
- exceptions might apply and are listed in NOTICE
- there is a new LICENSES folder with all licenses
- CONTRIBUTIONS.md has been updated accordingly
For automated changes based on OAI PL v1.1:
perl -i~ -0pe 's/\/\*.*Licensed to the OpenAirInterface.*openairinterface.org\n#?/\/*\n * SPDX-License-Identifier: LicenseRef-CSSL-1.0\n/s' **/*.{c,h,cpp}
perl -i~ -0pe 's/\/\*.*Licensed to the OpenAirInterface.*openairinterface.org\n#?/\/*\n * SPDX-License-Identifier: LicenseRef-CSSL-1.0\n/s' **/*.ts
perl -i~ -0pe 's/<!--.*Licensed to the OpenAirInterface.*openairinterface.org\n.*-->/<!-- SPDX-License-Identifier: LicenseRef-CSSL-1.0 -->/s' **/*.xml
The rest (cmake, files with missing license, cmake) manually.
The seq_arr_erase_it function was modifying start_it during the free_func loop,
which led to incorrectly apply the free_func on the whole array.
This commit makes sure the elements "freed" are only those in the range and not the whole seq_arr.
* Fixes the logic by introducing a temporary iterator for the free loop,
preserving start_it and end_it for correct offset calculations.
* Adds a regression test in test_seq_arr to verify that only the selected
subrange is erased and that free_func is called exactly on that range.
ngap_pdu_t has the same definition as byte_array_t, so it is
replaced by the latter. This simplify the stack and reduces
duplicated code.
Also, add function create_byte_array to copy from an
existing buffer to a new byte_array_t and replaced
allocCopy with create_byte_array, and adopted
OCTET_STRING_fromBuf whenever possible.
ran_func_kpm.c uses cp_ba_to_str(), but it is not defined in OAI. Define
it so we can link properly, instead of relying on FlexRIC (where it was
defined).
In a later commit, we will use find_if in L2. In the case of building
with E2 agent, we link e2_agent which comes with its own implementation
of find_if_arr(), which results in a name clash. Rename the OAI
implementation, as nothing uses this, anyway.
Using AssertFatal() has the drawback that it requires the definition of
an exit_function() (which is typically declared in OAI main
executables). We don't want to pull in such dependency for every
consumer. Hence, use c stdlib's assert() instead.
Robert Schmidt