The test_shared_relative function deadlocks on older Glibc versions that
don't have pthread_rwlock_clockrdlock, because (as already mentioned
earlier in the test file) pthread_rwlock_timedrdlock returns EDEADLK if
the thread that already holds a write lock attempts to acquire read
lock, causing std::shared_timed_mutex to loop forever.
The fix is to do the invalid try_lock_shared_for call on a different
thread.
Also add missing -pthread for PR122401.
libstdc++-v3/ChangeLog:
PR libstdc++/122401
* testsuite/30_threads/shared_timed_mutex/try_lock_until/116586.cc:
Do not call try_lock_shared_for from the thread that already
holds the exclusive lock. Add -pthread for et pthread.
---
Tested x86_64-linux (Glibc 2.41) and aarch64-linux (Glibc 2.28).
.../shared_timed_mutex/try_lock_until/116586.cc | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git
a/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/116586.cc
b/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/116586.cc
index cebbb3a258d9..aae85487a692 100644
---
a/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/116586.cc
+++
b/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/116586.cc
@@ -1,4 +1,7 @@
// { dg-do run { target c++14 } }
+// { dg-additional-options "-pthread" { target pthread } }
+// { dg-require-gthreads "" }
+// { dg-require-effective-target hosted }
#include <shared_mutex>
#include <chrono>
@@ -66,7 +69,14 @@ test_shared_relative(chrono::nanoseconds offset)
stm.unlock_shared();
// Should complete immediately
VERIFY(stm.try_lock_for(chrono::seconds{10}));
- VERIFY(!stm.try_lock_shared_for(d));
+ {
+ // NPTL will give us EDEADLK if pthread_rwlock_timedrdlock() is called on
+ // the same thread that already holds the exclusive (write) lock, so let's
+ // arrange for a different thread to try to acquire the shared lock.
+ auto t = std::async(std::launch::async, [&stm, d]() {
+ VERIFY(!stm.try_lock_shared_for(d));
+ });
+ }
}
int main()
--
2.51.0
