Add a C++11 ThreadPool implementation in LLVM

[oota-llvm.git] / unittests / Support / ThreadPool.cpp

diff --git a/unittests/Support/ThreadPool.cpp b/unittests/Support/ThreadPool.cpp
new file mode 100644 (file)
index 0000000..d36341e
--- /dev/null
+++ b/unittests/Support/ThreadPool.cpp
@@ -0,0 +1,91 @@
+//========- unittests/Support/ThreadPools.cpp - ThreadPools.h tests --========//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/ThreadPool.h"
+
+#include "llvm/ADT/STLExtras.h"
+
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace std::chrono;
+
+/// Try best to make this thread not progress faster than the main thread
+static void yield() {
+#ifdef LLVM_ENABLE_THREADS
+  std::this_thread::yield();
+#endif
+  std::this_thread::sleep_for(milliseconds(200));
+#ifdef LLVM_ENABLE_THREADS
+  std::this_thread::yield();
+#endif
+}
+
+TEST(ThreadPoolTest, AsyncBarrier) {
+  // test that async & barrier work together properly.
+
+  std::atomic_int checked_in{0};
+
+  ThreadPool Pool;
+  for (size_t i = 0; i < 5; ++i) {
+    Pool.async([&checked_in, i] {
+      yield();
+      ++checked_in;
+    });
+  }
+  ASSERT_EQ(0, checked_in);
+  Pool.wait();
+  ASSERT_EQ(5, checked_in);
+}
+
+TEST(ThreadPoolTest, Async) {
+  ThreadPool Pool;
+  std::atomic_int i{0};
+  // sleep here just to ensure that the not-equal is correct.
+  Pool.async([&i] {
+    yield();
+    ++i;
+  });
+  Pool.async([&i] { ++i; });
+  ASSERT_NE(2, i.load());
+  Pool.wait();
+  ASSERT_EQ(2, i.load());
+}
+
+TEST(ThreadPoolTest, GetFuture) {
+  ThreadPool Pool;
+  std::atomic_int i{0};
+  // sleep here just to ensure that the not-equal is correct.
+  Pool.async([&i] {
+    yield();
+    ++i;
+  });
+  // Force the future using get()
+  Pool.async([&i] { ++i; }).get();
+  ASSERT_NE(2, i.load());
+  Pool.wait();
+  ASSERT_EQ(2, i.load());
+}
+
+TEST(ThreadPoolTest, PoolDestruction) {
+  // Test that we are waiting on destruction
+  std::atomic_int checked_in{0};
+
+  {
+    ThreadPool Pool;
+    for (size_t i = 0; i < 5; ++i) {
+      Pool.async([&checked_in, i] {
+        yield();
+        ++checked_in;
+      });
+    }
+    ASSERT_EQ(0, checked_in);
+  }
+  ASSERT_EQ(5, checked_in);
+}