Windows: Refactor code related to a services discovering

* We do not need QtConcurrent for a services discovering
  because they returns from a cache immediately.

* We don't need to hold the opened device all the time after
  connection to it. It is enough to open a device only for a
  some time to request of services.

* Now the windows/qwinlowenergybluetooth_p.h file contains
  only resolved system LE functions and data types.

Change-Id: I248666d78cc9141bf987987dfd5dd9280decf4b8
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

5 files changed, 185 insertions, 295 deletions

diff --git a/src/bluetooth/qlowenergycontroller_p.h b/src/bluetooth/qlowenergycontroller_p.h
index 6d81316d..fde057cf 100644
--- a/src/bluetooth/qlowenergycontroller_p.h
+++ b/src/bluetooth/qlowenergycontroller_p.h
@@ -65,12 +65,6 @@ QT_END_NAMESPACE
 #include "android/lowenergynotificationhub_p.h"
 #endif
 
-#if defined(Q_OS_WIN32)
-#include <QtConcurrent>
-#include <QtBluetooth/qbluetoothuuid.h>
-#include "windows/qwinlowenergybluetooth_p.h"
-#endif
-
 QT_BEGIN_NAMESPACE
 
 #if defined(QT_BLUEZ_BLUETOOTH) && !defined(QT_BLUEZ_NO_BTLE)
@@ -227,15 +221,8 @@ private slots:
     void characteristicChanged(int charHandle, const QByteArray &data);
     void serviceError(int attributeHandle, QLowEnergyService::ServiceError errorCode);
 #elif defined(Q_OS_WIN32)
-private slots:
-    void primaryServicesDiscoveryCompleted();
-
 private:
-    void startDiscoveryOfPrimaryServices();
-    bool isConnected() const;
-
-    HANDLE hRemoteDevice;
-    QFutureWatcher<WinLowEnergyBluetooth::ServicesDiscoveryResult> *primaryServicesDiscoveryWatcher;
+    QString deviceSystemPath;
 #endif
 private:
     QLowEnergyController *q_ptr;
diff --git a/src/bluetooth/qlowenergycontroller_win.cpp b/src/bluetooth/qlowenergycontroller_win.cpp
index ed33c5c8..0f629a0b 100644
--- a/src/bluetooth/qlowenergycontroller_win.cpp
+++ b/src/bluetooth/qlowenergycontroller_win.cpp
@@ -37,17 +37,80 @@
 
 #include <QtCore/QLoggingCategory>
 
+#include <windows/qwinlowenergybluetooth_p.h>
+
 QT_BEGIN_NAMESPACE
 
 Q_DECLARE_LOGGING_CATEGORY(QT_BT_WINDOWS)
 
+Q_GLOBAL_STATIC(QLibrary, bluetoothapis)
+
+static bool gattFunctionsResolved = false;
+
+static HANDLE openSystemDevice(const QString &systemPath, int *systemErrorCode)
+{
+    const DWORD desiredAccess = GENERIC_READ | GENERIC_WRITE;
+    const DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
+    const HANDLE serviceHandle = ::CreateFile(
+                reinterpret_cast<const wchar_t *>(systemPath.utf16()),
+                desiredAccess,
+                shareMode,
+                NULL,
+                OPEN_EXISTING,
+                0,
+                NULL);
+
+    *systemErrorCode = (INVALID_HANDLE_VALUE == serviceHandle)
+            ? ::GetLastError() : NO_ERROR;
+    return serviceHandle;
+}
+
+static void closeSystemDevice(HANDLE deviceHandle)
+{
+    if (deviceHandle && deviceHandle != INVALID_HANDLE_VALUE)
+        ::CloseHandle(deviceHandle);
+}
+
+static QVector<BTH_LE_GATT_SERVICE> enumeratePrimaryGattServices(
+        HANDLE deviceHandle, int *systemErrorCode)
+{
+    if (!gattFunctionsResolved) {
+        *systemErrorCode = ERROR_NOT_SUPPORTED;
+        return QVector<BTH_LE_GATT_SERVICE>();
+    }
+
+    QVector<BTH_LE_GATT_SERVICE> foundServices;
+    USHORT servicesCount = 0;
+    forever {
+        const HRESULT hr = ::BluetoothGATTGetServices(
+                    deviceHandle,
+                    servicesCount,
+                    foundServices.isEmpty() ? NULL : &foundServices[0],
+                    &servicesCount,
+                    BLUETOOTH_GATT_FLAG_NONE);
+
+        if (hr == HRESULT_FROM_WIN32(ERROR_MORE_DATA)) {
+            foundServices.resize(servicesCount);
+        } else if (hr == S_OK) {
+            *systemErrorCode = NO_ERROR;
+            return foundServices;
+        } else {
+            *systemErrorCode = ::GetLastError();
+            return QVector<BTH_LE_GATT_SERVICE>();
+        }
+    }
+}
+
 QLowEnergyControllerPrivate::QLowEnergyControllerPrivate()
-    : QObject(),
-      state(QLowEnergyController::UnconnectedState),
-      error(QLowEnergyController::NoError),
-      hRemoteDevice(INVALID_HANDLE_VALUE),
-      primaryServicesDiscoveryWatcher(0)
+    : QObject()
+    , state(QLowEnergyController::UnconnectedState)
+    , error(QLowEnergyController::NoError)
 {
+    gattFunctionsResolved = resolveFunctions(bluetoothapis());
+    if (!gattFunctionsResolved) {
+        qCWarning(QT_BT_WINDOWS) << "LE is not supported on this OS";
+        return;
+    }
 }
 
 QLowEnergyControllerPrivate::~QLowEnergyControllerPrivate()
@@ -56,8 +119,6 @@ QLowEnergyControllerPrivate::~QLowEnergyControllerPrivate()
 
 void QLowEnergyControllerPrivate::connectToDevice()
 {
-    Q_Q(QLowEnergyController);
-
     // required to pass unit test on default backend
     if (remoteDevice.isNull()) {
         qWarning() << "Invalid/null remote device address";
@@ -65,78 +126,97 @@ void QLowEnergyControllerPrivate::connectToDevice()
         return;
     }
 
-    if (!WinLowEnergyBluetooth::isSupported()) {
-        qWarning() << "Low energy is not supported by OS";
-        setError(QLowEnergyController::UnknownError);
-        return;
-    }
-
-    if (isConnected()) {
+    if (!deviceSystemPath.isEmpty()) {
         qCDebug(QT_BT_WINDOWS) << "Already is connected";
         return;
     }
 
     setState(QLowEnergyController::ConnectingState);
 
-    const QString deviceSystemPath = QBluetoothDeviceDiscoveryAgentPrivate::discoveredLeDeviceSystemPath(remoteDevice);
-
-    const DWORD desiredAccess = GENERIC_READ | GENERIC_WRITE;
-    const DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
-
-    hRemoteDevice = ::CreateFile(
-                reinterpret_cast<const wchar_t *>(deviceSystemPath.utf16()),
-                desiredAccess,
-                shareMode,
-                NULL,
-                OPEN_EXISTING,
-                0,
-                NULL);
+    deviceSystemPath =
+            QBluetoothDeviceDiscoveryAgentPrivate::discoveredLeDeviceSystemPath(
+                remoteDevice);
 
-    if (hRemoteDevice == INVALID_HANDLE_VALUE) {
-        qCWarning(QT_BT_WINDOWS) << qt_error_string(::GetLastError());
-        setError(QLowEnergyController::ConnectionError);
+    if (deviceSystemPath.isEmpty()) {
+        qCWarning(QT_BT_WINDOWS) << qt_error_string(ERROR_PATH_NOT_FOUND);
+        setError(QLowEnergyController::UnknownRemoteDeviceError);
         setState(QLowEnergyController::UnconnectedState);
         return;
     }
 
     setState(QLowEnergyController::ConnectedState);
+
+    Q_Q(QLowEnergyController);
     emit q->connected();
 }
 
 void QLowEnergyControllerPrivate::disconnectFromDevice()
 {
-    Q_Q(QLowEnergyController);
-
-    if (!WinLowEnergyBluetooth::isSupported()) {
-        qWarning() << "Low energy is not supported by OS";
-        setError(QLowEnergyController::UnknownError);
-        return;
-    }
-
-    if (!isConnected()) {
+    if (deviceSystemPath.isEmpty()) {
         qCDebug(QT_BT_WINDOWS) << "Already is disconnected";
         return;
     }
 
     setState(QLowEnergyController::ClosingState);
-
-    if (!::CloseHandle(hRemoteDevice))
-        qCWarning(QT_BT_WINDOWS) << qt_error_string(::GetLastError());
-
-    hRemoteDevice = INVALID_HANDLE_VALUE;
+    deviceSystemPath.clear();
     setState(QLowEnergyController::UnconnectedState);
+
+    Q_Q(QLowEnergyController);
     emit q->disconnected();
 }
 
 void QLowEnergyControllerPrivate::discoverServices()
 {
-    if (!WinLowEnergyBluetooth::isSupported()) {
-        qWarning() << "Low energy is not supported by OS";
-        setError(QLowEnergyController::UnknownError);
+    int systemErrorCode = NO_ERROR;
+
+    const HANDLE deviceHandle = openSystemDevice(deviceSystemPath, &systemErrorCode);
+
+    if (systemErrorCode != NO_ERROR) {
+        qCWarning(QT_BT_WINDOWS) << qt_error_string(systemErrorCode);
+        setError(QLowEnergyController::NetworkError);
+        setState(QLowEnergyController::ConnectedState);
+        return;
+    }
+
+    const QVector<BTH_LE_GATT_SERVICE> foundServices =
+            enumeratePrimaryGattServices(deviceHandle, &systemErrorCode);
+
+    closeSystemDevice(deviceHandle);
+
+    if (systemErrorCode != NO_ERROR) {
+        qCWarning(QT_BT_WINDOWS) << qt_error_string(systemErrorCode);
+        setError(QLowEnergyController::NetworkError);
+        setState(QLowEnergyController::ConnectedState);
         return;
     }
 
-    startDiscoveryOfPrimaryServices();
+    setState(QLowEnergyController::DiscoveringState);
+
+    Q_Q(QLowEnergyController);
+
+    foreach (const BTH_LE_GATT_SERVICE &service, foundServices) {
+
+        const QBluetoothUuid uuid(
+                    service.ServiceUuid.IsShortUuid
+                    ? QBluetoothUuid(service.ServiceUuid.Value.ShortUuid)
+                    : QBluetoothUuid(service.ServiceUuid.Value.LongUuid));
+
+        qCDebug(QT_BT_WINDOWS) << "Found uuid:" << uuid;
+
+        QLowEnergyServicePrivate *priv = new QLowEnergyServicePrivate();
+        priv->uuid = uuid;
+        priv->type = QLowEnergyService::PrimaryService;
+        priv->startHandle = service.AttributeHandle;
+        priv->setController(this);
+
+        QSharedPointer<QLowEnergyServicePrivate> pointer(priv);
+        serviceList.insert(uuid, pointer);
+
+        emit q->serviceDiscovered(uuid);
+    }
+
+    setState(QLowEnergyController::DiscoveredState);
+    emit q->discoveryFinished();
 }
 
 void QLowEnergyControllerPrivate::discoverServiceDetails(
@@ -178,69 +258,4 @@ void QLowEnergyControllerPrivate::writeDescriptor(
 
 }
 
-void QLowEnergyControllerPrivate::primaryServicesDiscoveryCompleted()
-{
-    Q_Q(QLowEnergyController);
-
-    const WinLowEnergyBluetooth::ServicesDiscoveryResult result =
-            primaryServicesDiscoveryWatcher->result();
-
-    if (result.error != NO_ERROR) {
-        qCWarning(QT_BT_WINDOWS) << qt_error_string(result.error);
-        setError(QLowEnergyController::UnknownError);
-        return;
-    }
-
-    foreach (const WinLowEnergyBluetooth::BTH_LE_GATT_SERVICE &service,
-             result.services) {
-
-        const QBluetoothUuid uuid(
-                    service.ServiceUuid.IsShortUuid
-                    ? QBluetoothUuid(service.ServiceUuid.Value.ShortUuid)
-                    : QBluetoothUuid(service.ServiceUuid.Value.LongUuid));
-
-        qCDebug(QT_BT_WINDOWS) << "Found uuid:" << uuid;
-
-        QLowEnergyServicePrivate *priv = new QLowEnergyServicePrivate();
-        priv->uuid = uuid;
-        priv->type = QLowEnergyService::PrimaryService;
-        priv->startHandle = service.AttributeHandle;
-        priv->setController(this);
-
-        QSharedPointer<QLowEnergyServicePrivate> pointer(priv);
-
-        serviceList.insert(uuid, pointer);
-        emit q->serviceDiscovered(uuid);
-    }
-
-    setState(QLowEnergyController::DiscoveredState);
-    emit q->discoveryFinished();
-}
-
-void QLowEnergyControllerPrivate::startDiscoveryOfPrimaryServices()
-{
-    if (!primaryServicesDiscoveryWatcher) {
-        primaryServicesDiscoveryWatcher = new QFutureWatcher<
-                WinLowEnergyBluetooth::ServicesDiscoveryResult>(this);
-
-        connect(primaryServicesDiscoveryWatcher, &QFutureWatcher<WinLowEnergyBluetooth::ServicesDiscoveryResult>::finished,
-                this, &QLowEnergyControllerPrivate::primaryServicesDiscoveryCompleted);
-    }
-
-    if (primaryServicesDiscoveryWatcher->isRunning())
-        return;
-
-    const QFuture<WinLowEnergyBluetooth::ServicesDiscoveryResult> future =
-            QtConcurrent::run(
-                WinLowEnergyBluetooth::startDiscoveryOfPrimaryServices,
-                hRemoteDevice);
-
-    primaryServicesDiscoveryWatcher->setFuture(future);
-}
-
-bool QLowEnergyControllerPrivate::isConnected() const
-{
-    return hRemoteDevice && (hRemoteDevice != INVALID_HANDLE_VALUE);
-}
-
 QT_END_NAMESPACE
diff --git a/src/bluetooth/windows/qwinlowenergybluetooth.cpp b/src/bluetooth/windows/qwinlowenergybluetooth.cpp
deleted file mode 100644
index 8033a121..00000000
--- a/src/bluetooth/windows/qwinlowenergybluetooth.cpp
+++ /dev/null
@@ -1,144 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Copyright (C) 2014 Denis Shienkov <denis.shienkov@gmail.com>
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the QtBluetooth module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL21$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 2.1 or version 3 as published by the Free
-** Software Foundation and appearing in the file LICENSE.LGPLv21 and
-** LICENSE.LGPLv3 included in the packaging of this file. Please review the
-** following information to ensure the GNU Lesser General Public License
-** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** As a special exception, The Qt Company gives you certain additional
-** rights. These rights are described in The Qt Company LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qwinlowenergybluetooth_p.h"
-
-#include <QtCore/quuid.h>
-#include <QtCore/qlibrary.h>
-#include <QtCore/qglobal.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace WinLowEnergyBluetooth {
-
-#define DEFINEFUNC(ret, func, ...) \
-    typedef ret (WINAPI *fp_##func)(__VA_ARGS__); \
-    static fp_##func func;
-
-#define RESOLVEFUNC(func) \
-    func = (fp_##func)resolveFunction(library, #func); \
-    if (!func) \
-        return false;
-
-DEFINEFUNC(HRESULT, BluetoothGATTGetServices, HANDLE, USHORT, PBTH_LE_GATT_SERVICE, PUSHORT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTGetIncludedServices, HANDLE, PBTH_LE_GATT_SERVICE, USHORT, PBTH_LE_GATT_SERVICE, PUSHORT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTGetCharacteristics, HANDLE, PBTH_LE_GATT_SERVICE, USHORT, PBTH_LE_GATT_CHARACTERISTIC, PUSHORT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTGetDescriptors, HANDLE, PBTH_LE_GATT_CHARACTERISTIC, USHORT, PBTH_LE_GATT_DESCRIPTOR, PUSHORT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTGetCharacteristicValue, HANDLE, PBTH_LE_GATT_CHARACTERISTIC, ULONG, PBTH_LE_GATT_CHARACTERISTIC_VALUE, PUSHORT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTGetDescriptorValue, HANDLE, PBTH_LE_GATT_DESCRIPTOR, ULONG, PBTH_LE_GATT_DESCRIPTOR_VALUE, PUSHORT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTBeginReliableWrite, HANDLE, PBTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTEndReliableWrite, HANDLE, BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTAbortReliableWrite, HANDLE, BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTSetCharacteristicValue, HANDLE, PBTH_LE_GATT_CHARACTERISTIC, PBTH_LE_GATT_CHARACTERISTIC_VALUE, BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTSetDescriptorValue, HANDLE, PBTH_LE_GATT_DESCRIPTOR, PBTH_LE_GATT_DESCRIPTOR_VALUE, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTRegisterEvent, HANDLE, BTH_LE_GATT_EVENT_TYPE, PVOID, PFNBLUETOOTH_GATT_EVENT_CALLBACK, PVOID, PHANDLE, ULONG)
-DEFINEFUNC(HRESULT, BluetoothGATTUnregisterEvent, HANDLE, ULONG)
-
-static inline QFunctionPointer resolveFunction(QLibrary *library, const char *func)
-{
-    QFunctionPointer symbolFunctionPointer = library->resolve(func);
-    if (!symbolFunctionPointer)
-        qWarning("Cannot resolve '%s' in '%s'.", func, qPrintable(library->fileName()));
-    return symbolFunctionPointer;
-}
-
-static inline bool resolveFunctions(QLibrary *library)
-{
-    if (!library->isLoaded()) {
-        library->setFileName(QStringLiteral("bluetoothapis"));
-        if (!library->load()) {
-            qWarning("Unable to load '%s' library.", qPrintable(library->fileName()));
-            return false;
-        }
-    }
-
-    RESOLVEFUNC(BluetoothGATTGetServices)
-    RESOLVEFUNC(BluetoothGATTGetIncludedServices)
-    RESOLVEFUNC(BluetoothGATTGetCharacteristics)
-    RESOLVEFUNC(BluetoothGATTGetDescriptors)
-    RESOLVEFUNC(BluetoothGATTGetCharacteristicValue)
-    RESOLVEFUNC(BluetoothGATTGetDescriptorValue)
-    RESOLVEFUNC(BluetoothGATTBeginReliableWrite)
-    RESOLVEFUNC(BluetoothGATTEndReliableWrite)
-    RESOLVEFUNC(BluetoothGATTAbortReliableWrite)
-    RESOLVEFUNC(BluetoothGATTSetCharacteristicValue)
-    RESOLVEFUNC(BluetoothGATTSetDescriptorValue)
-    RESOLVEFUNC(BluetoothGATTRegisterEvent)
-    RESOLVEFUNC(BluetoothGATTUnregisterEvent)
-
-    return true;
-}
-
-Q_GLOBAL_STATIC(QLibrary, bluetoothapis)
-
-ServicesDiscoveryResult::ServicesDiscoveryResult()
-    : error(NO_ERROR)
-{
-}
-
-ServicesDiscoveryResult startDiscoveryOfPrimaryServices(
-        HANDLE hDevice)
-{
-    ServicesDiscoveryResult result;
-    USHORT servicesCount = 0;
-    forever {
-        const HRESULT hr = BluetoothGATTGetServices(
-                    hDevice,
-                    result.services.count(),
-                    result.services.isEmpty() ? NULL : &result.services[0],
-                    &servicesCount,
-                    BLUETOOTH_GATT_FLAG_NONE);
-
-        if (hr == HRESULT_FROM_WIN32(ERROR_MORE_DATA)) {
-            result.services.resize(servicesCount);
-        } else if (hr == S_OK) {
-            break;
-        } else {
-            result.error = ::GetLastError();
-            result.services.clear();
-            break;
-        }
-    }
-    return result;
-}
-
-bool isSupported()
-{
-    static bool resolved = resolveFunctions(bluetoothapis());
-    return resolved;
-}
-
-} // namespace WinLowEnergyBluetooth
-
-QT_END_NAMESPACE
diff --git a/src/bluetooth/windows/qwinlowenergybluetooth_p.h b/src/bluetooth/windows/qwinlowenergybluetooth_p.h
index c591a93d..c12ea4ae 100644
--- a/src/bluetooth/windows/qwinlowenergybluetooth_p.h
+++ b/src/bluetooth/windows/qwinlowenergybluetooth_p.h
@@ -35,17 +35,9 @@
 #ifndef QWINLOWENERGYBLUETOOTH_P_H
 #define QWINLOWENERGYBLUETOOTH_P_H
 
-#include <QtCore/qstringlist.h>
-#include <QtCore/qvector.h>
-
-#include <QtBluetooth/qbluetoothaddress.h>
+#include <QtCore/qlibrary.h>
 
 #include <qt_windows.h>
-#include <setupapi.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace WinLowEnergyBluetooth {
 
 #define BLUETOOTH_GATT_FLAG_NONE                        0x00000000
 #define BLUETOOTH_GATT_FLAG_CONNECTION_ENCRYPTED        0x00000001
@@ -157,19 +149,62 @@ typedef VOID (CALLBACK *PFNBLUETOOTH_GATT_EVENT_CALLBACK)(
 
 typedef ULONG64 BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, *PBTH_LE_GATT_RELIABLE_WRITE_CONTEXT;
 
-struct ServicesDiscoveryResult
+#define DEFINEFUNC(ret, func, ...) \
+    typedef ret (WINAPI *fp_##func)(__VA_ARGS__); \
+    static fp_##func func;
+
+#define RESOLVEFUNC(func) \
+    func = (fp_##func)resolveFunction(library, #func); \
+    if (!func) \
+        return false;
+
+DEFINEFUNC(HRESULT, BluetoothGATTGetServices, HANDLE, USHORT, PBTH_LE_GATT_SERVICE, PUSHORT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTGetIncludedServices, HANDLE, PBTH_LE_GATT_SERVICE, USHORT, PBTH_LE_GATT_SERVICE, PUSHORT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTGetCharacteristics, HANDLE, PBTH_LE_GATT_SERVICE, USHORT, PBTH_LE_GATT_CHARACTERISTIC, PUSHORT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTGetDescriptors, HANDLE, PBTH_LE_GATT_CHARACTERISTIC, USHORT, PBTH_LE_GATT_DESCRIPTOR, PUSHORT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTGetCharacteristicValue, HANDLE, PBTH_LE_GATT_CHARACTERISTIC, ULONG, PBTH_LE_GATT_CHARACTERISTIC_VALUE, PUSHORT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTGetDescriptorValue, HANDLE, PBTH_LE_GATT_DESCRIPTOR, ULONG, PBTH_LE_GATT_DESCRIPTOR_VALUE, PUSHORT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTBeginReliableWrite, HANDLE, PBTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTEndReliableWrite, HANDLE, BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTAbortReliableWrite, HANDLE, BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTSetCharacteristicValue, HANDLE, PBTH_LE_GATT_CHARACTERISTIC, PBTH_LE_GATT_CHARACTERISTIC_VALUE, BTH_LE_GATT_RELIABLE_WRITE_CONTEXT, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTSetDescriptorValue, HANDLE, PBTH_LE_GATT_DESCRIPTOR, PBTH_LE_GATT_DESCRIPTOR_VALUE, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTRegisterEvent, HANDLE, BTH_LE_GATT_EVENT_TYPE, PVOID, PFNBLUETOOTH_GATT_EVENT_CALLBACK, PVOID, PHANDLE, ULONG)
+DEFINEFUNC(HRESULT, BluetoothGATTUnregisterEvent, HANDLE, ULONG)
+
+static inline QFunctionPointer resolveFunction(QLibrary *library, const char *func)
 {
-    ServicesDiscoveryResult();
-    QVector<BTH_LE_GATT_SERVICE> services;
-    DWORD error;
-};
-
-bool isSupported();
+    QFunctionPointer symbolFunctionPointer = library->resolve(func);
+    if (!symbolFunctionPointer)
+        qWarning("Cannot resolve '%s' in '%s'.", func, qPrintable(library->fileName()));
+    return symbolFunctionPointer;
+}
 
-ServicesDiscoveryResult startDiscoveryOfPrimaryServices(HANDLE hDevice);
-
-} // namespace WinLowEnergyBluetooth
-
-QT_END_NAMESPACE
+static inline bool resolveFunctions(QLibrary *library)
+{
+    if (!library->isLoaded()) {
+        library->setFileName(QStringLiteral("bluetoothapis"));
+        if (!library->load()) {
+            qWarning("Unable to load '%s' library.", qPrintable(library->fileName()));
+            return false;
+        }
+    }
+
+    RESOLVEFUNC(BluetoothGATTGetServices)
+    RESOLVEFUNC(BluetoothGATTGetIncludedServices)
+    RESOLVEFUNC(BluetoothGATTGetCharacteristics)
+    RESOLVEFUNC(BluetoothGATTGetDescriptors)
+    RESOLVEFUNC(BluetoothGATTGetCharacteristicValue)
+    RESOLVEFUNC(BluetoothGATTGetDescriptorValue)
+    RESOLVEFUNC(BluetoothGATTBeginReliableWrite)
+    RESOLVEFUNC(BluetoothGATTEndReliableWrite)
+    RESOLVEFUNC(BluetoothGATTAbortReliableWrite)
+    RESOLVEFUNC(BluetoothGATTSetCharacteristicValue)
+    RESOLVEFUNC(BluetoothGATTSetDescriptorValue)
+    RESOLVEFUNC(BluetoothGATTRegisterEvent)
+    RESOLVEFUNC(BluetoothGATTUnregisterEvent)
+
+    return true;
+}
 
 #endif // QWINLOWENERGYBLUETOOTH_P_H
diff --git a/src/bluetooth/windows/windows.pri b/src/bluetooth/windows/windows.pri
index 019d67e4..bf35eaa4 100644
--- a/src/bluetooth/windows/windows.pri
+++ b/src/bluetooth/windows/windows.pri
@@ -1,5 +1,2 @@
 PRIVATE_HEADERS += \
     windows/qwinlowenergybluetooth_p.h
-
-SOURCES += \
-    windows/qwinlowenergybluetooth.cpp