latch: add simple latch based on a mutex and cv

1 files changed, 37 insertions, 0 deletions

diff --git a/test/latch.cc b/test/latch.cc
new file mode 100644
index 0000000..567e3db
--- /dev/null
+++ b/test/latch.cc
@@ -0,0 +1,37 @@
+#include <latch.h>
+
+#include <chrono>
+#include <thread>
+#include <vector>
+
+#include <cassert>
+#include <cstdio>
+
+constexpr unsigned kNumThreads = 16;
+
+int main() {
+  latch gate(kNumThreads);
+
+  std::vector<std::thread> threads;
+  threads.reserve(kNumThreads);
+
+  for (unsigned t = 0; t < kNumThreads; ++t) {
+    threads.emplace_back([&gate, t]() {
+      if (t % 2 == 0) {
+        unsigned sec = t / 2;
+        std::printf("th%02u sleep %us\n", t, sec);
+        std::this_thread::sleep_for(std::chrono::seconds(sec));
+      }
+
+      std::printf("th%02u at gate\n", t);
+      gate.arrive_and_wait();
+      std::printf("th%02u finished\n", t);
+    });
+  }
+
+  for (auto& th : threads) {
+    th.join();
+  }
+
+  return 0;
+}