1 files changed, 169 insertions, 0 deletions
diff --git a/comphelper/qa/unit/threadpooltest.cxx b/comphelper/qa/unit/threadpooltest.cxx
new file mode 100644
index 000000000..13eaf210a
--- /dev/null
+++ b/comphelper/qa/unit/threadpooltest.cxx
@@ -0,0 +1,169 @@
+/* -*- 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 <tools/time.hxx>
+#include <osl/thread.hxx>
+
+#include <stdlib.h>
+#include <atomic>
+#include <cstddef>
+#include <thread>
+#include <mutex>
+
+class ThreadPoolTest : public CppUnit::TestFixture
+{
+public:
+    void testPreferredConcurrency();
+    void testWorkerUsage();
+    void testTasksInThreads();
+    void testNoThreads();
+    void testDedicatedPool();
+
+    CPPUNIT_TEST_SUITE(ThreadPoolTest);
+    CPPUNIT_TEST(testPreferredConcurrency);
+    CPPUNIT_TEST(testWorkerUsage);
+    CPPUNIT_TEST(testTasksInThreads);
+    CPPUNIT_TEST(testNoThreads);
+    CPPUNIT_TEST(testDedicatedPool);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+void ThreadPoolTest::testPreferredConcurrency()
+{
+    // Check default.
+    auto nThreads = comphelper::ThreadPool::getPreferredConcurrency();
+    std::size_t 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 <= 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
+}
+
+namespace
+{
+class UsageTask : public comphelper::ThreadTask
+{
+public:
+    UsageTask(const std::shared_ptr<comphelper::ThreadTaskTag>& pTag)
+        : ThreadTask(pTag)
+    {
+    }
+    virtual void doWork()
+    {
+        ++count;
+        mutex.lock();
+        mutex.unlock();
+    }
+    static inline std::atomic<int> count = 0;
+    static inline std::mutex mutex;
+};
+} // namespace
+
+void ThreadPoolTest::testWorkerUsage()
+{
+    // Create tasks for each available worker. Lock a shared mutex before that to make all
+    // tasks block on it. And check that all workers have started, i.e. that the full
+    // thread pool capacity is used.
+    comphelper::ThreadPool& rSharedPool = comphelper::ThreadPool::getSharedOptimalPool();
+    std::shared_ptr<comphelper::ThreadTaskTag> pTag = comphelper::ThreadPool::createThreadTaskTag();
+    UsageTask::mutex.lock();
+    for (int i = 0; i < rSharedPool.getWorkerCount(); ++i)
+    {
+        rSharedPool.pushTask(std::make_unique<UsageTask>(pTag));
+        osl::Thread::wait(std::chrono::milliseconds(10)); // give it a time to start
+    }
+    sal_uInt64 startTicks = tools::Time::GetSystemTicks();
+    while (UsageTask::count != rSharedPool.getWorkerCount())
+    {
+        // Wait at most 5 seconds, that should do even on slow systems.
+        CPPUNIT_ASSERT_MESSAGE("Thread pool does not use all worker threads.",
+                               startTicks + 5000 > tools::Time::GetSystemTicks());
+        osl::Thread::wait(std::chrono::milliseconds(10));
+    }
+    UsageTask::mutex.unlock();
+    rSharedPool.waitUntilDone(pTag);
+}
+
+namespace
+{
+class CheckThreadTask : public comphelper::ThreadTask
+{
+    oslThreadIdentifier mThreadId;
+    bool mCheckEqual;
+
+public:
+    CheckThreadTask(oslThreadIdentifier threadId, bool checkEqual,
+                    const std::shared_ptr<comphelper::ThreadTaskTag>& pTag)
+        : ThreadTask(pTag)
+        , mThreadId(threadId)
+        , mCheckEqual(checkEqual)
+    {
+    }
+    virtual void doWork()
+    {
+        CPPUNIT_ASSERT(mCheckEqual ? osl::Thread::getCurrentIdentifier() == mThreadId
+                                   : osl::Thread::getCurrentIdentifier() != mThreadId);
+    }
+};
+} // namespace
+
+void ThreadPoolTest::testTasksInThreads()
+{
+    // Check that all tasks are run in worker threads, not this thread.
+    comphelper::ThreadPool& pool = comphelper::ThreadPool::getSharedOptimalPool();
+    std::shared_ptr<comphelper::ThreadTaskTag> pTag = comphelper::ThreadPool::createThreadTaskTag();
+    for (int i = 0; i < 8; ++i)
+        pool.pushTask(
+            std::make_unique<CheckThreadTask>(osl::Thread::getCurrentIdentifier(), false, pTag));
+    pool.waitUntilDone(pTag);
+}
+
+void ThreadPoolTest::testNoThreads()
+{
+    // No worker threads, tasks will be run in this thread.
+    comphelper::ThreadPool pool(0);
+    std::shared_ptr<comphelper::ThreadTaskTag> pTag = comphelper::ThreadPool::createThreadTaskTag();
+    for (int i = 0; i < 8; ++i)
+        pool.pushTask(
+            std::make_unique<CheckThreadTask>(osl::Thread::getCurrentIdentifier(), true, pTag));
+    pool.waitUntilDone(pTag);
+}
+
+void ThreadPoolTest::testDedicatedPool()
+{
+    // Test that a separate thread pool works. The tasks themselves do not matter.
+    comphelper::ThreadPool pool(4);
+    std::shared_ptr<comphelper::ThreadTaskTag> pTag = comphelper::ThreadPool::createThreadTaskTag();
+    for (int i = 0; i < 8; ++i)
+        pool.pushTask(
+            std::make_unique<CheckThreadTask>(osl::Thread::getCurrentIdentifier(), false, pTag));
+    pool.waitUntilDone(pTag);
+}
+
+CPPUNIT_TEST_SUITE_REGISTRATION(ThreadPoolTest);
+
+CPPUNIT_PLUGIN_IMPLEMENT();
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */