diff options
| -rw-r--r-- | compiler-rt/lib/tsan/rtl/tsan_interceptors.cc | 36 | ||||
| -rw-r--r-- | compiler-rt/test/tsan/load_shared_lib.cc | 2 | ||||
| -rw-r--r-- | compiler-rt/test/tsan/test.h | 31 |
3 files changed, 51 insertions, 18 deletions
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc index 2741af88b09..57a676f8d72 100644 --- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc +++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc @@ -2683,3 +2683,39 @@ void InitializeInterceptors() { } } // namespace __tsan + +// Invisible barrier for tests. +// There were several unsuccessful iterations for this functionality: +// 1. Initially it was implemented in user code using +// REAL(pthread_barrier_wait). But pthread_barrier_wait is not supported on +// MacOS. Futexes are linux-specific for this matter. +// 2. Then we switched to atomics+usleep(10). But usleep produced parasitic +// "as-if synchronized via sleep" messages in reports which failed some +// output tests. +// 3. Then we switched to atomics+sched_yield. But this produced tons of tsan- +// visible events, which lead to "failed to restore stack trace" failures. +// Note that no_sanitize_thread attribute does not turn off atomic interception +// so attaching it to the function defined in user code does not help. +// That's why we now have what we have. +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +void __tsan_testonly_barrier_init(u64 *barrier, u32 count) { + if (count >= (1 << 8)) { + Printf("barrier_init: count is too large (%d)\n", count); + Die(); + } + // 8 lsb is thread count, the remaining are count of entered threads. + *barrier = count; +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +void __tsan_testonly_barrier_wait(u64 *barrier) { + unsigned old = __atomic_fetch_add(barrier, 1 << 8, __ATOMIC_RELAXED); + unsigned old_epoch = (old >> 8) / (old & 0xff); + for (;;) { + unsigned cur = __atomic_load_n(barrier, __ATOMIC_RELAXED); + unsigned cur_epoch = (cur >> 8) / (cur & 0xff); + if (cur_epoch != old_epoch) + return; + internal_sched_yield(); + } +} diff --git a/compiler-rt/test/tsan/load_shared_lib.cc b/compiler-rt/test/tsan/load_shared_lib.cc index b7934b82df7..f02280895f8 100644 --- a/compiler-rt/test/tsan/load_shared_lib.cc +++ b/compiler-rt/test/tsan/load_shared_lib.cc @@ -3,7 +3,7 @@ // symbolized correctly. // RUN: %clangxx_tsan -O1 %s -DBUILD_SO -fPIC -shared -o %t-so.so -// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s +// RUN: %clangxx_tsan -O1 %s -o %t -rdynamic && %deflake %run %t | FileCheck %s #ifdef BUILD_SO diff --git a/compiler-rt/test/tsan/test.h b/compiler-rt/test/tsan/test.h index e7ffefdcf21..cec7c0d32f8 100644 --- a/compiler-rt/test/tsan/test.h +++ b/compiler-rt/test/tsan/test.h @@ -14,27 +14,24 @@ // TSan-invisible barrier. // Tests use it to establish necessary execution order in a way that does not // interfere with tsan (does not establish synchronization between threads). -// 8 lsb is thread count, the remaining are count of entered threads. typedef unsigned long long invisible_barrier_t; -void barrier_init(invisible_barrier_t *barrier, unsigned count) { - if (count >= (1 << 8)) - exit(fprintf(stderr, "barrier_init: count is too large (%d)\n", count)); - *barrier = count; +#ifdef __cplusplus +extern "C" { +#endif +void __tsan_testonly_barrier_init(invisible_barrier_t *barrier, + unsigned count); +void __tsan_testonly_barrier_wait(invisible_barrier_t *barrier); +#ifdef __cplusplus } +#endif -void barrier_wait(invisible_barrier_t *barrier) { - unsigned old = __atomic_fetch_add(barrier, 1 << 8, __ATOMIC_RELAXED); - unsigned old_epoch = (old >> 8) / (old & 0xff); - for (;;) { - unsigned cur = __atomic_load_n(barrier, __ATOMIC_RELAXED); - unsigned cur_epoch = (cur >> 8) / (cur & 0xff); - if (cur_epoch != old_epoch) - return; - // Can't use usleep, because it leads to spurious "As if synchronized via - // sleep" messages which fail some output tests. - sched_yield(); - } +static inline void barrier_init(invisible_barrier_t *barrier, unsigned count) { + __tsan_testonly_barrier_init(barrier, count); +} + +static inline void barrier_wait(invisible_barrier_t *barrier) { + __tsan_testonly_barrier_wait(barrier); } // Default instance of the barrier, but a test can declare more manually. |
