1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 // WARNING: DO NOT USE THIS 20 // You should: 21 // - have code know how it is handling things. Pass in caller information rather 22 // than assuming that code is running in a specific global context 23 // - use AIDL exclusively in your stack (HIDL is no longer required anywhere) 24 25 #include <binder/IPCThreadState.h> 26 #include <hwbinder/IPCThreadState.h> 27 28 namespace android { 29 30 enum class BinderCallType { 31 NONE, 32 BINDER, 33 HWBINDER, 34 }; 35 36 // Based on where we are in recursion of nested binder/hwbinder calls, determine 37 // which one we are closer to. getCurrentServingCall()38inline static BinderCallType getCurrentServingCall() { 39 auto* hwState = android::hardware::IPCThreadState::selfOrNull(); 40 auto* state = android::IPCThreadState::selfOrNull(); 41 42 // getServingStackPointer can also return nullptr 43 const void* hwbinderSp = hwState ? hwState->getServingStackPointer() : nullptr; 44 const void* binderSp = state ? state->getServingStackPointer() : nullptr; 45 46 if (hwbinderSp == nullptr && binderSp == nullptr) return BinderCallType::NONE; 47 if (hwbinderSp == nullptr) return BinderCallType::BINDER; 48 if (binderSp == nullptr) return BinderCallType::HWBINDER; 49 50 if (hwbinderSp < binderSp) return BinderCallType::HWBINDER; 51 return BinderCallType::BINDER; 52 } 53 54 } // namespace android 55