Every entry point may now be called from any thread. akerr_init() runs
exactly once however many threads race into it, the pool hands each slot
to exactly one thread, and reservations, registrations and lookups are
serialized against each other.
One recursive lock covers both tables (src/lock.h, private). Recursive
because raising an error re-enters the library -- FAIL needs a pool slot
and a status name -- and single because two locks would mean an ordering
to get wrong. Registry bodies that use the early-returning FAIL_*_RETURN
macros are split into *_locked functions behind wrappers that take and
release the lock on one path; consumer callbacks are never called under
it.
This is an ABI break, hence 2.0.0 and SOVERSION 2:
- akerr_next_error() now returns a context that already holds its
reference. Finding a free slot and claiming it has to be one operation,
or two threads scanning at once are handed the same slot.
ENSURE_ERROR_READY no longer increments.
- __akerr_last_ignored is thread-local, as is the last-ditch context used
to report akerr_release_error(NULL).
The threading backend is chosen at configure time by AKERR_THREADS
(auto, pthread, none). auto fails the configure when it cannot find
POSIX threads rather than quietly building a library that reports itself
thread safe and is not. generrno.sh stamps the decision into the
generated header as AKERR_THREAD_SAFE, so a consumer cannot disagree
with the library about it.
Tests: err_threads_init, err_threads_pool and err_threads_registry
assert exclusive slot ownership, exactly one winner for a contested
range, and every registered name readable back under contention.
AKERR_SANITIZE builds the library and the tests with any sanitizer;
scripts/thread_test.sh runs the suite under ThreadSanitizer and CI runs
it. Removing the pool lock makes both the sanitizer and the plain
assertions fail, so the tests are not vacuous.
Documented in README.md and UPGRADING.md, including what this does not
cover: renaming a status while another thread looks it up, and which of
two simultaneous unhandled errors sets the exit status.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
akerr_reserve_status_range() and akerr_register_status_name() returned
private int enumerations, which was the one place in the library where a
failure was not an akerr_ErrorContext *. They now return one like
everything else: NULL on success, and on refusal an error whose status is
a real code in the library's reserved band, so it can be CATCH-ed,
HANDLE-d, PASS-ed, or left to propagate into a stack trace. Both are
marked AKERR_NOIGNORE, so discarding the result warns at compile time.
AKERR_STATUS_RANGE_OK and AKERR_STATUS_NAME_OK are gone; the remaining
seven codes move into the AKERR_* offset span and get registered names.
AKERR_LAST_LIBRARY_STATUS replaces AKERR_BADEXC as the top of that span
in the reserved-band static assert and the exhaustiveness sweep.
The refusal detail that used to go straight to akerr_log_method now
travels in the error message, so a caller that handles the error decides
whether it is reported. The two-argument akerr_name_for_status() set path
is the exception: it returns a name and cannot raise, so it logs and
releases. akerr_init() likewise has no caller to raise into, so failing
to reserve its own band or name its own codes is logged and fatal --
that can only happen on a misconfigured build, and continuing would
degrade every later stack trace to "Unknown Error".
Move the 1.0.0 upgrade notice out of README.md into UPGRADING.md and
rewrite its return-code tables in terms of the statuses now raised.
Tests: ctest 29/29, coverage 97.5% line / 64.5% branch, mutation 77.5%
(was 77.6%; the new survivors are the fatal init path, which needs a
library built with an undersized name table -- TODO item 7).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
