Bug 446139 DRD/Helgrind with std::shared_timed_mutex::try_lock_until and try_lock_shared_until false positives

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Bug 446138 DRD/Helgrind with std::timed_mutex::try_lock_until false positives

drd/tests/shared_timed_mutex.cpp

@@ -0,0 +1,63 @@
+#include <thread>
+#include <iostream>
+#include <chrono>
+#include <shared_mutex>
+#include <mutex>
+#include <cassert>
+#include <condition_variable>
+
+std::shared_timed_mutex test_mutex;
+std::mutex cv_mutex;
+std::condition_variable cv;
+int global;
+bool reads_done = false;
+ 
+void f()
+{
+    auto now=std::chrono::steady_clock::now();
+    if (test_mutex.try_lock_until(now + std::chrono::seconds(3)))
+    {
+       --global;
+       test_mutex.unlock();
+    }
+    else
+    {
+        std::cerr << "Lock failed\n";
+    }
+}
+
+void g()
+{
+    auto now=std::chrono::steady_clock::now();
+    if (test_mutex.try_lock_shared_until(now + std::chrono::seconds(2)))
+    {
+       test_mutex.unlock_shared();
+    }
+    else
+    {
+        std::cerr << "Lock shared failed\n";
+    }
+    std::unique_lock<std::mutex> lock(cv_mutex);
+    reads_done = true;
+    cv.notify_all();
+}
+ 
+int main()
+{
+    global = 1;
+    test_mutex.lock_shared();
+    std::thread t1(f);
+    std::thread t2(g);
+    {
+       std::unique_lock<std::mutex> lock(cv_mutex);
+       while (!reads_done)
+       {
+          cv.wait(lock);
+       }
+    }
+    test_mutex.unlock_shared();
+    t1.join();
+    t2.join();
+    assert(global == 0);
+}
+