1 files changed, 95 insertions, 0 deletions
diff --git a/src/corelib/thread/qfutex_linux_p.h b/src/corelib/thread/qfutex_linux_p.h
new file mode 100644
index 0000000000..e114dfca72
--- /dev/null
+++ b/src/corelib/thread/qfutex_linux_p.h
@@ -0,0 +1,95 @@
+// Copyright (C) 2023 Intel Corporation.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QFUTEX_LINUX_P_H
+#define QFUTEX_LINUX_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qcore_unix_p.h>
+#include <qdeadlinetimer.h>
+#include <qtsan_impl.h>
+
+#include <asm/unistd.h>
+#include <errno.h>
+#include <limits.h>
+#include <linux/futex.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+// RISC-V does not supply __NR_futex
+#ifndef __NR_futex
+#  define __NR_futex __NR_futex_time64
+#endif
+
+#define QT_ALWAYS_USE_FUTEX
+
+QT_BEGIN_NAMESPACE
+
+namespace QtLinuxFutex {
+constexpr inline bool futexAvailable() { return true; }
+
+inline int _q_futex(int *addr, int op, int val, quintptr val2 = 0,
+                    int *addr2 = nullptr, int val3 = 0) noexcept
+{
+    QtTsan::futexRelease(addr, addr2);
+
+    // we use __NR_futex because some libcs (like Android's bionic) don't
+    // provide SYS_futex etc.
+    int result = syscall(__NR_futex, addr, op | FUTEX_PRIVATE_FLAG, val, val2, addr2, val3);
+
+    QtTsan::futexAcquire(addr, addr2);
+
+    return result;
+}
+template <typename T> int *addr(T *ptr)
+{
+    int *int_addr = reinterpret_cast<int *>(ptr);
+#if Q_BYTE_ORDER == Q_BIG_ENDIAN
+    if (sizeof(T) > sizeof(int))
+        int_addr++; //We want a pointer to the least significant half
+#endif
+    return int_addr;
+}
+
+template <typename Atomic>
+inline void futexWait(Atomic &futex, typename Atomic::Type expectedValue)
+{
+    _q_futex(addr(&futex), FUTEX_WAIT, qintptr(expectedValue));
+}
+template <typename Atomic>
+inline bool futexWait(Atomic &futex, typename Atomic::Type expectedValue, QDeadlineTimer deadline)
+{
+    auto timeout = deadline.deadline<std::chrono::steady_clock>().time_since_epoch();
+    struct timespec ts = durationToTimespec(timeout);
+    int r = _q_futex(addr(&futex), FUTEX_WAIT_BITSET, qintptr(expectedValue), quintptr(&ts),
+                     nullptr, FUTEX_BITSET_MATCH_ANY);
+    return r == 0 || errno != ETIMEDOUT;
+}
+template <typename Atomic> inline void futexWakeOne(Atomic &futex)
+{
+    _q_futex(addr(&futex), FUTEX_WAKE, 1);
+}
+template <typename Atomic> inline void futexWakeAll(Atomic &futex)
+{
+    _q_futex(addr(&futex), FUTEX_WAKE, INT_MAX);
+}
+template <typename Atomic> inline
+void futexWakeOp(Atomic &futex1, int wake1, int wake2, Atomic &futex2, quint32 op)
+{
+    _q_futex(addr(&futex1), FUTEX_WAKE_OP, wake1, wake2, addr(&futex2), op);
+}} // namespace QtLinuxFutex
+namespace QtFutex = QtLinuxFutex;
+
+QT_END_NAMESPACE
+
+#endif // QFUTEX_LINUX_P_H