[controller] add Thread controller interface for unified APIs

src/dbus/server/dbus_thread_object.cpp

@@ -660,14 +660,19 @@ otError DBusThreadObject::GetLinkModeHandler(DBusMessageIter &aIter)
 
 otError DBusThreadObject::GetDeviceRoleHandler(DBusMessageIter &aIter)
 {
-    auto         threadHelper = mHost->GetThreadHelper();
-    otDeviceRole role         = otThreadGetDeviceRole(threadHelper->GetInstance());
-    std::string  roleName     = GetDeviceRoleName(role);
-    otError      error        = OT_ERROR_NONE;
+    otError error = OT_ERROR_NONE;
 
-    VerifyOrExit(DBusMessageEncodeToVariant(&aIter, roleName) == OTBR_ERROR_NONE, error = OT_ERROR_INVALID_ARGS);
+    mHost->GetDeviceRole([&aIter, &error](otError aError, otDeviceRole aRole) mutable {
+        OTBR_UNUSED_VARIABLE(aError);
+        std::string roleName = GetDeviceRoleName(aRole);
+        otbrError   err      = DBusMessageEncodeToVariant(&aIter, roleName);
+
+        if (err != OTBR_ERROR_NONE)
+        {
+            error = OT_ERROR_INVALID_ARGS;
+        }
+    });
 
-exit:
     return error;
 }
 

src/ncp/rcp_host.cpp

@@ -402,6 +402,12 @@ const char *RcpHost::GetThreadVersion(void)
     return version;
 }
 
+void RcpHost::GetDeviceRole(DeviceRoleHandler aHandler)
+{
+    otDeviceRole role = otThreadGetDeviceRole(mInstance);
+    aHandler(OT_ERROR_NONE, role);
+}
+
 /*
  * Provide, if required an "otPlatLog()" function
  */

src/ncp/rcp_host.hpp

@@ -49,6 +49,7 @@
 #include "common/mainloop.hpp"
 #include "common/task_runner.hpp"
 #include "common/types.hpp"
+#include "ncp/thread_controller.hpp"
 #include "utils/thread_helper.hpp"
 
 namespace otbr {
@@ -63,7 +64,7 @@ namespace Ncp {
  * This interface defines OpenThread Controller under RCP mode.
  *
  */
-class RcpHost : public MainloopProcessor
+class RcpHost : public MainloopProcessor, public ThreadController
 {
 public:
     using ThreadStateChangedCallback = std::function<void(otChangedFlags aFlags)>;
@@ -193,6 +194,9 @@ class RcpHost : public MainloopProcessor
 
     ~RcpHost(void) override;
 
+    // Thread Control APIs
+    void GetDeviceRole(DeviceRoleHandler aHandler) override;
+
 private:
     static void HandleStateChanged(otChangedFlags aFlags, void *aContext)
     {

src/ncp/thread_controller.hpp

@@ -0,0 +1,67 @@
+/*
+ *  Copyright (c) 2024, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ *   This file includes definitions of Thead Controller Interface.
+ */
+
+#ifndef OTBR_AGENT_THREAD_CONTROLLER_HPP_
+#define OTBR_AGENT_THREAD_CONTROLLER_HPP_
+
+#include <functional>
+#include <vector>
+
+#include <openthread/error.h>
+#include <openthread/thread.h>
+
+#include "lib/spinel/coprocessor_type.h"
+
+#include "common/logging.hpp"
+
+namespace otbr {
+namespace Ncp {
+
+class ThreadController
+{
+public:
+    /**
+     * Thread Control API: GetDeviceRole
+     *
+     * This method gets the device role and return the role through the handler.
+     *
+     * @param[in]  aHandler   A handler to return the role.
+     */
+    using DeviceRoleHandler                                = std::function<void(otError, otDeviceRole)>;
+    virtual void GetDeviceRole(DeviceRoleHandler aHandler) = 0;
+};
+
+} // namespace Ncp
+} // namespace otbr
+
+#endif // OTBR_AGENT_THREAD_CONTROLLER_HPP_