Dining philosophers test or toy benchmark

polytypic · polytypic · commit 54d42bd42f9e · 2019-09-03T23:38:47.000+03:00
diff --git a/internals/testing/dining_test.cpp b/internals/testing/dining_test.cpp
@@ -0,0 +1,49 @@
+#include "trade_v1/trade.hpp"
+
+#include "testing_v1/test.hpp"
+
+#include <thread>
+
+using namespace trade_v1;
+using namespace testing_v1;
+
+constexpr size_t n_to_eat = 100000;
+constexpr size_t n_philosophers = 5;
+
+struct fork {
+  fork() : on_table(true) {}
+
+  alignas(64) atom<bool> on_table;
+};
+
+auto dining_test = test([]() {
+  atom<size_t> done = 0;
+
+  fork forks[n_philosophers];
+
+  for (size_t philosopher = 0; philosopher < n_philosophers; ++philosopher)
+    std::thread([&, philosopher]() {
+      auto &left = forks[philosopher];
+      auto &right = forks[(philosopher + 1) % n_philosophers];
+
+      for (size_t e = 0; e < n_to_eat; ++e) {
+        atomically([&]() {
+          bool &left_on_table = left.on_table.ref();
+          bool &right_on_table = right.on_table.ref();
+          if (left_on_table && right_on_table)
+            left_on_table = right_on_table = false;
+          else
+            retry();
+        });
+
+        atomically([&]() { left.on_table = right.on_table = true; });
+      }
+
+      atomically([&]() { ++done.ref(); });
+    }).detach();
+
+  atomically([&]() {
+    if (done != n_philosophers)
+      retry();
+  });
+});
