1 files changed, 55 insertions, 0 deletions
diff --git a/comphelper/qa/unit/threadpooltest.cxx b/comphelper/qa/unit/threadpooltest.cxx
new file mode 100644
index 000000000..10fb90c30
--- /dev/null
+++ b/comphelper/qa/unit/threadpooltest.cxx
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <comphelper/threadpool.hxx>
+#include <cppunit/TestAssert.h>
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/plugin/TestPlugIn.h>
+
+#include <stdlib.h>
+#include <thread>
+
+class ThreadPoolTest : public CppUnit::TestFixture
+{
+public:
+    void testPreferredConcurrency();
+
+    CPPUNIT_TEST_SUITE(ThreadPoolTest);
+    CPPUNIT_TEST(testPreferredConcurrency);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+void ThreadPoolTest::testPreferredConcurrency()
+{
+    // Check default.
+    auto nThreads = comphelper::ThreadPool::getPreferredConcurrency();
+    sal_Int32 nExpected = 4; // UTs are capped to 4.
+    CPPUNIT_ASSERT_MESSAGE("Expected no more than 4 threads", nExpected >= nThreads);
+
+#ifndef _WIN32
+    // The result should be cached, so this should change anything.
+    nThreads = std::thread::hardware_concurrency() * 2;
+    setenv("MAX_CONCURRENCY", std::to_string(nThreads).c_str(), true);
+    nThreads = comphelper::ThreadPool::getPreferredConcurrency();
+    CPPUNIT_ASSERT_MESSAGE("Expected no more than hardware threads",
+                           nThreads <= static_cast<sal_Int32>(std::thread::hardware_concurrency()));
+
+    // Revert and check. Again, nothing should change.
+    unsetenv("MAX_CONCURRENCY");
+    nThreads = comphelper::ThreadPool::getPreferredConcurrency();
+    CPPUNIT_ASSERT_MESSAGE("Expected no more than 4 threads", nExpected >= nThreads);
+#endif
+}
+
+CPPUNIT_TEST_SUITE_REGISTRATION(ThreadPoolTest);
+
+CPPUNIT_PLUGIN_IMPLEMENT();
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */