diff options
| -rw-r--r-- | lib/frrcu.h | 2 | ||||
| -rw-r--r-- | lib/seqlock.c | 33 | ||||
| -rw-r--r-- | tests/lib/test_atomlist.c | 18 | ||||
| -rw-r--r-- | tests/lib/test_seqlock.c | 5 |
4 files changed, 46 insertions, 12 deletions
diff --git a/lib/frrcu.h b/lib/frrcu.h index 9f07a69b52..81ab5528a9 100644 --- a/lib/frrcu.h +++ b/lib/frrcu.h @@ -156,7 +156,7 @@ extern void rcu_enqueue(struct rcu_head *head, const struct rcu_action *action); #define rcu_call(func, ptr, field) \ do { \ typeof(ptr) _ptr = (ptr); \ - void (*fptype)(typeof(ptr)); \ + void (*_fptype)(typeof(ptr)); \ struct rcu_head *_rcu_head = &_ptr->field; \ static const struct rcu_action _rcu_action = { \ .type = RCUA_CALL, \ diff --git a/lib/seqlock.c b/lib/seqlock.c index 62ce316920..e74e6718bf 100644 --- a/lib/seqlock.c +++ b/lib/seqlock.c @@ -26,6 +26,39 @@ * OS specific synchronization wrappers * ****************************************/ +#ifndef __has_feature /* not available on old GCC */ +#define __has_feature(x) 0 +#endif + +#if (defined(__SANITIZE_THREAD__) || __has_feature(thread_sanitizer)) +/* TSAN really does not understand what is going on with the low-level + * futex/umtx calls. This leads to a whole bunch of warnings, a lot of which + * also have _extremely_ misleading text - since TSAN does not understand that + * there is in fact a synchronization primitive involved, it can end up pulling + * in completely unrelated things. + * + * What does work is the "unsupported platform" seqlock implementation based + * on a pthread mutex + condvar, since TSAN of course suppports these. + * + * It may be possible to also fix this with TSAN annotations (__tsan_acquire + * and __tsan_release), but using those (correctly) is not easy either, and + * for now just get things rolling. + */ + +#ifdef HAVE_SYNC_LINUX_FUTEX +#undef HAVE_SYNC_LINUX_FUTEX +#endif + +#ifdef HAVE_SYNC_OPENBSD_FUTEX +#undef HAVE_SYNC_OPENBSD_FUTEX +#endif + +#ifdef HAVE_SYNC_UMTX_OP +#undef HAVE_SYNC_UMTX_OP +#endif + +#endif /* TSAN */ + /* * Linux: sys_futex() */ diff --git a/tests/lib/test_atomlist.c b/tests/lib/test_atomlist.c index b50216cf92..afcfa98791 100644 --- a/tests/lib/test_atomlist.c +++ b/tests/lib/test_atomlist.c @@ -62,7 +62,7 @@ static struct asort_head shead; static struct testthread { pthread_t pt; struct seqlock sqlo; - size_t counter, nullops; + _Atomic size_t counter, nullops; } thr[NTHREADS]; struct testrun { @@ -97,10 +97,10 @@ static void trfunc_##name(unsigned int offset) \ { \ size_t i = 0, n = 0; -#define endtestrun \ - thr[offset].counter = i; \ - thr[offset].nullops = n; \ -} +#define endtestrun \ + atomic_store_explicit(&thr[offset].counter, i, memory_order_seq_cst); \ + atomic_store_explicit(&thr[offset].nullops, n, memory_order_seq_cst); \ + } deftestrun(add, "add vs. add", 0, false) for (; i < NITEM / NTHREADS; i++) @@ -288,10 +288,10 @@ static void run_tr(struct testrun *tr) sv = seqlock_bump(&sqlo) - SEQLOCK_INCR; for (size_t i = 0; i < NTHREADS; i++) { seqlock_wait(&thr[i].sqlo, seqlock_cur(&sqlo)); - s += thr[i].counter; - n += thr[i].nullops; - thr[i].counter = 0; - thr[i].nullops = 0; + s += atomic_load_explicit(&thr[i].counter, memory_order_seq_cst); + n += atomic_load_explicit(&thr[i].nullops, memory_order_seq_cst); + atomic_store_explicit(&thr[i].counter, 0, memory_order_seq_cst); + atomic_store_explicit(&thr[i].nullops, 0, memory_order_seq_cst); } delta = monotime_since(&tv, NULL); diff --git a/tests/lib/test_seqlock.c b/tests/lib/test_seqlock.c index 288d4a8c25..937b3f34f5 100644 --- a/tests/lib/test_seqlock.c +++ b/tests/lib/test_seqlock.c @@ -82,11 +82,11 @@ int main(int argc, char **argv) assert(seqlock_held(&sqlo)); assert(seqlock_cur(&sqlo) == 1); - assert(seqlock_bump(&sqlo) == 1); - assert(seqlock_cur(&sqlo) == 5); assert(seqlock_bump(&sqlo) == 5); + assert(seqlock_cur(&sqlo) == 5); assert(seqlock_bump(&sqlo) == 9); assert(seqlock_bump(&sqlo) == 13); + assert(seqlock_bump(&sqlo) == 17); assert(seqlock_cur(&sqlo) == 17); assert(seqlock_held(&sqlo)); @@ -111,4 +111,5 @@ int main(int argc, char **argv) writestr("main @release\n"); seqlock_release(&sqlo); sleep(1); + pthread_join(thr1, NULL); } |