mutex: add owning mutex utility

1 files changed, 41 insertions, 0 deletions

diff --git a/test/owning_mutex.cc b/test/owning_mutex.cc
new file mode 100644
index 0000000..060415f
--- /dev/null
+++ b/test/owning_mutex.cc
@@ -0,0 +1,41 @@
+#include <owning_mutex.h>
+
+#include <limits>
+#include <thread>
+#include <vector>
+
+#include <cassert>
+#include <cstdio>
+
+constexpr unsigned kNumThreads = 8;
+constexpr unsigned kIter = 1 << 18;
+
+static_assert((static_cast<unsigned long>(kNumThreads) *
+               static_cast<unsigned long>(kIter)) <=
+                  std::numeric_limits<unsigned>::max(),
+              "Expectate result overflowed!");
+
+int main() {
+  owning_mutex<unsigned> data(0u);
+
+  std::vector<std::thread> threads;
+  threads.reserve(kNumThreads);
+
+  for (unsigned t = 0; t < kNumThreads; ++t) {
+    threads.emplace_back([&data, t]() {
+      for (unsigned i = 0; i < kIter; ++i) {
+        *data.lock() += 1;
+      }
+      std::printf("th%u finished\n", t);
+    });
+  }
+
+  for (auto& th : threads) {
+    th.join();
+  }
+
+  assert(*data.lock() == (kNumThreads * kIter));
+  std::printf("Result %u\n", *data.lock());
+
+  return 0;
+}