1 files changed, 298 insertions, 0 deletions
diff --git a/tests/benchmarks/corelib/thread/qreadwritelock/tst_bench_qreadwritelock.cpp b/tests/benchmarks/corelib/thread/qreadwritelock/tst_bench_qreadwritelock.cpp
new file mode 100644
index 0000000000..e63ac6573f
--- /dev/null
+++ b/tests/benchmarks/corelib/thread/qreadwritelock/tst_bench_qreadwritelock.cpp
@@ -0,0 +1,298 @@
+// Copyright (C) 2016 Olivier Goffart <ogoffart@woboq.com>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include <QtCore/QtCore>
+#include <QTest>
+#include <mutex>
+#if __has_include(<shared_mutex>)
+#include <shared_mutex>
+#endif
+#include <vector>
+
+// Wrapers that take pointers instead of reference to have the same interface as Qt
+template <typename T>
+struct LockerWrapper : T
+{
+    LockerWrapper(typename T::mutex_type *mtx)
+        : T(*mtx)
+    {
+    }
+};
+
+struct QRecursiveReadWriteLock : QReadWriteLock
+{
+    QRecursiveReadWriteLock() : QReadWriteLock(Recursive) {}
+};
+
+template <typename T, size_t N>
+  // requires N = 2^M for some Integral M >= 0
+struct Recursive
+{
+    Recursive<T, N/2> r1, r2;
+
+    template <typename...Args>
+    Q_ALWAYS_INLINE
+    explicit Recursive(Args &&...args)
+        : r1(args...),
+          r2(args...)
+    {}
+};
+
+template <typename T>
+struct Recursive<T, 1>
+{
+    T t;
+    template <typename...Args>
+    Q_ALWAYS_INLINE
+    explicit Recursive(Args &&...args)
+        : t(args...) {}
+};
+
+template <typename T>
+struct Recursive<T, 0>
+{
+    template <typename...Args>
+    Q_ALWAYS_INLINE
+    explicit Recursive(Args &&...) {}
+};
+
+template <size_t N>
+using QRecursiveReadLocker = Recursive<QReadLocker, N>;
+
+template <size_t N>
+using QRecursiveWriteLocker = Recursive<QWriteLocker, N>;
+
+int threadCount;
+
+class tst_QReadWriteLock : public QObject
+{
+    Q_OBJECT
+public:
+    tst_QReadWriteLock()
+    {
+        // at least 2 threads, even on single cpu/core machines
+        threadCount = qMax(2, QThread::idealThreadCount());
+        qDebug("thread count: %d", threadCount);
+    }
+
+private slots:
+    void uncontended_data();
+    void uncontended();
+    void readOnly_data();
+    void readOnly();
+    void writeOnly_data();
+    void writeOnly();
+    // void readWrite();
+};
+
+struct FunctionPtrHolder
+{
+    FunctionPtrHolder(QFunctionPointer value = nullptr)
+        : value(value)
+    {
+    }
+    QFunctionPointer value;
+};
+Q_DECLARE_METATYPE(FunctionPtrHolder)
+
+struct FakeLock
+{
+    FakeLock(volatile int *i) { *i = 0; }
+};
+
+enum { Iterations = 1000000 };
+
+template <typename Mutex, typename Locker>
+void testUncontended()
+{
+    Mutex lock;
+    QBENCHMARK {
+        for (int i = 0; i < Iterations; ++i) {
+            Locker locker(&lock);
+        }
+    }
+}
+
+void tst_QReadWriteLock::uncontended_data()
+{
+    QTest::addColumn<FunctionPtrHolder>("holder");
+
+    QTest::newRow("nothing") << FunctionPtrHolder(testUncontended<int, FakeLock>);
+    QTest::newRow("QMutex") << FunctionPtrHolder(testUncontended<QMutex, QMutexLocker<QMutex>>);
+    QTest::newRow("QReadWriteLock, read")
+        << FunctionPtrHolder(testUncontended<QReadWriteLock, QReadLocker>);
+    QTest::newRow("QReadWriteLock, write")
+        << FunctionPtrHolder(testUncontended<QReadWriteLock, QWriteLocker>);
+#define ROW(n) \
+    QTest::addRow("QReadWriteLock, %s, recursive: %d", "read", n) \
+        << FunctionPtrHolder(testUncontended<QRecursiveReadWriteLock, QRecursiveReadLocker<n>>); \
+    QTest::addRow("QReadWriteLock, %s, recursive: %d", "write", n) \
+        << FunctionPtrHolder(testUncontended<QRecursiveReadWriteLock, QRecursiveWriteLocker<n>>)
+    ROW(1);
+    ROW(2);
+    ROW(32);
+#undef ROW
+    QTest::newRow("std::mutex") << FunctionPtrHolder(
+        testUncontended<std::mutex, LockerWrapper<std::unique_lock<std::mutex>>>);
+#ifdef __cpp_lib_shared_mutex
+    QTest::newRow("std::shared_mutex, read") << FunctionPtrHolder(
+        testUncontended<std::shared_mutex,
+                        LockerWrapper<std::shared_lock<std::shared_mutex>>>);
+    QTest::newRow("std::shared_mutex, write") << FunctionPtrHolder(
+        testUncontended<std::shared_mutex,
+                        LockerWrapper<std::unique_lock<std::shared_mutex>>>);
+#endif
+#if defined __cpp_lib_shared_timed_mutex
+    QTest::newRow("std::shared_timed_mutex, read") << FunctionPtrHolder(
+        testUncontended<std::shared_timed_mutex,
+                        LockerWrapper<std::shared_lock<std::shared_timed_mutex>>>);
+    QTest::newRow("std::shared_timed_mutex, write") << FunctionPtrHolder(
+        testUncontended<std::shared_timed_mutex,
+                        LockerWrapper<std::unique_lock<std::shared_timed_mutex>>>);
+#endif
+}
+
+void tst_QReadWriteLock::uncontended()
+{
+    QFETCH(FunctionPtrHolder, holder);
+    holder.value();
+}
+
+static QHash<QString, QString> global_hash;
+
+template <typename Mutex, typename Locker>
+void testReadOnly()
+{
+    struct Thread : QThread
+    {
+        Mutex *lock;
+        void run() override
+        {
+            for (int i = 0; i < Iterations; ++i) {
+                QString s = QString::number(i); // Do something outside the lock
+                Locker locker(lock);
+                global_hash.contains(s);
+            }
+        }
+    };
+    Mutex lock;
+    std::vector<std::unique_ptr<Thread>> threads;
+    for (int i = 0; i < threadCount; ++i) {
+        auto t = std::make_unique<Thread>();
+        t->lock = &lock;
+        threads.push_back(std::move(t));
+    }
+    QBENCHMARK {
+        for (auto &t : threads) {
+            t->start();
+        }
+        for (auto &t : threads) {
+            t->wait();
+        }
+    }
+}
+
+void tst_QReadWriteLock::readOnly_data()
+{
+    QTest::addColumn<FunctionPtrHolder>("holder");
+
+    QTest::newRow("nothing") << FunctionPtrHolder(testReadOnly<int, FakeLock>);
+    QTest::newRow("QMutex") << FunctionPtrHolder(testReadOnly<QMutex, QMutexLocker<QMutex>>);
+    QTest::newRow("QReadWriteLock") << FunctionPtrHolder(testReadOnly<QReadWriteLock, QReadLocker>);
+#define ROW(n) \
+    QTest::addRow("QReadWriteLock, recursive: %d", n) \
+        << FunctionPtrHolder(testReadOnly<QRecursiveReadWriteLock, QRecursiveReadLocker<n>>)
+    ROW(1);
+    ROW(2);
+    ROW(32);
+#undef ROW
+    QTest::newRow("std::mutex") << FunctionPtrHolder(
+        testReadOnly<std::mutex, LockerWrapper<std::unique_lock<std::mutex>>>);
+#ifdef __cpp_lib_shared_mutex
+    QTest::newRow("std::shared_mutex") << FunctionPtrHolder(
+        testReadOnly<std::shared_mutex,
+                     LockerWrapper<std::shared_lock<std::shared_mutex>>>);
+#endif
+#if defined __cpp_lib_shared_timed_mutex
+    QTest::newRow("std::shared_timed_mutex") << FunctionPtrHolder(
+        testReadOnly<std::shared_timed_mutex,
+                     LockerWrapper<std::shared_lock<std::shared_timed_mutex>>>);
+#endif
+}
+
+void tst_QReadWriteLock::readOnly()
+{
+    QFETCH(FunctionPtrHolder, holder);
+    holder.value();
+}
+
+static QString global_string;
+
+template <typename Mutex, typename Locker>
+void testWriteOnly()
+{
+    struct Thread : QThread
+    {
+        Mutex *lock;
+        void run() override
+        {
+            for (int i = 0; i < Iterations; ++i) {
+                QString s = QString::number(i); // Do something outside the lock
+                Locker locker(lock);
+                global_string = s;
+            }
+        }
+    };
+    Mutex lock;
+    std::vector<std::unique_ptr<Thread>> threads;
+    for (int i = 0; i < threadCount; ++i) {
+        auto t = std::make_unique<Thread>();
+        t->lock = &lock;
+        threads.push_back(std::move(t));
+    }
+    QBENCHMARK {
+        for (auto &t : threads) {
+            t->start();
+        }
+        for (auto &t : threads) {
+            t->wait();
+        }
+    }
+}
+
+void tst_QReadWriteLock::writeOnly_data()
+{
+    QTest::addColumn<FunctionPtrHolder>("holder");
+
+    // QTest::newRow("nothing") << FunctionPtrHolder(testWriteOnly<int, FakeLock>);
+    QTest::newRow("QMutex") << FunctionPtrHolder(testWriteOnly<QMutex, QMutexLocker<QMutex>>);
+    QTest::newRow("QReadWriteLock") << FunctionPtrHolder(testWriteOnly<QReadWriteLock, QWriteLocker>);
+#define ROW(n) \
+    QTest::addRow("QReadWriteLock, recursive: %d", n) \
+        << FunctionPtrHolder(testWriteOnly<QRecursiveReadWriteLock, QRecursiveWriteLocker<n>>)
+    ROW(1);
+    ROW(2);
+    ROW(32);
+#undef ROW
+    QTest::newRow("std::mutex") << FunctionPtrHolder(
+        testWriteOnly<std::mutex, LockerWrapper<std::unique_lock<std::mutex>>>);
+#ifdef __cpp_lib_shared_mutex
+    QTest::newRow("std::shared_mutex") << FunctionPtrHolder(
+        testWriteOnly<std::shared_mutex,
+                     LockerWrapper<std::unique_lock<std::shared_mutex>>>);
+#endif
+#if defined __cpp_lib_shared_timed_mutex
+    QTest::newRow("std::shared_timed_mutex") << FunctionPtrHolder(
+        testWriteOnly<std::shared_timed_mutex,
+                     LockerWrapper<std::unique_lock<std::shared_timed_mutex>>>);
+#endif
+}
+
+void tst_QReadWriteLock::writeOnly()
+{
+    QFETCH(FunctionPtrHolder, holder);
+    holder.value();
+}
+
+QTEST_MAIN(tst_QReadWriteLock)
+#include "tst_bench_qreadwritelock.moc"