[libcxx-commits] [PATCH] D131483: [libcxx] [test] Make some threading tests more robust

[Martin Storsjö via Phabricator via libcxx-commits]

mstorsjo created this revision.
mstorsjo added a reviewer: ldionne.
Herald added a project: All.
mstorsjo requested review of this revision.
Herald added a project: libc++.
Herald added a reviewer: libc++.

Increase the timeout tolerance if TEST_HAS_SANITIZERS is set, similarly
to how it's done in a couple other tests.

Use `std::this_thread::yield();` instead of busylooping. When multiple
threads are busylooping, it's plausible that not all threads even get
started running before the timeout runs out.

This makes the threading tests succeed if run in Windows runners on
Github Actions.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D131483

Files:
  libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp
  libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/try_lock_shared.pass.cpp
  libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp


Index: libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp
===================================================================
--- libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp
+++ libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp
@@ -51,7 +51,7 @@
     assert(!m.try_lock_shared());
     assert(!m.try_lock_shared());
     while(!m.try_lock_shared())
-        ;
+        std::this_thread::yield();
     time_point t1 = Clock::now();
     m.unlock_shared();
     ns d = t1 - t0 - ms(250);
Index: libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/try_lock_shared.pass.cpp
===================================================================
--- libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/try_lock_shared.pass.cpp
+++ libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/try_lock_shared.pass.cpp
@@ -37,6 +37,13 @@
 typedef std::chrono::milliseconds ms;
 typedef std::chrono::nanoseconds ns;
 
+
+#if !defined(TEST_HAS_SANITIZERS)
+ms Tolerance = ms(200);
+#else
+ms Tolerance = ms(200 * 5);
+#endif
+
 void f()
 {
     time_point t0 = Clock::now();
@@ -44,11 +51,11 @@
     assert(!m.try_lock_shared());
     assert(!m.try_lock_shared());
     while(!m.try_lock_shared())
-        ;
+        std::this_thread::yield();
     time_point t1 = Clock::now();
     m.unlock_shared();
     ns d = t1 - t0 - ms(250);
-    assert(d < ms(200));  // within 200ms
+    assert(d < Tolerance);  // within tolerance
 }
 
 
Index: libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp
===================================================================
--- libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp
+++ libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp
@@ -36,6 +36,13 @@
 typedef std::chrono::milliseconds ms;
 typedef std::chrono::nanoseconds ns;
 
+
+#if !defined(TEST_HAS_SANITIZERS)
+ms Tolerance = ms(200);
+#else
+ms Tolerance = ms(200 * 5);
+#endif
+
 void f()
 {
     time_point t0 = Clock::now();
@@ -56,10 +63,11 @@
         std::shared_lock<std::shared_timed_mutex> lk(m, std::try_to_lock);
         if (lk.owns_lock())
             break;
+        std::this_thread::yield();
     }
     time_point t1 = Clock::now();
     ns d = t1 - t0 - ms(250);
-    assert(d < ms(200));  // within 200ms
+    assert(d < Tolerance);  // within tolerance
 }
 
 int main(int, char**)


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