| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ANDROID_BINDER_STATUS_H |
| #define ANDROID_BINDER_STATUS_H |
| |
| #include <cstdint> |
| #include <sstream> |
| |
| #include <binder/Parcel.h> |
| #include <utils/String8.h> |
| #include <string> |
| |
| namespace android { |
| namespace binder { |
| |
| // An object similar in function to a status_t except that it understands |
| // how exceptions are encoded in the prefix of a Parcel. Used like: |
| // |
| // Parcel data; |
| // Parcel reply; |
| // status_t status; |
| // binder::Status remote_exception; |
| // if ((status = data.writeInterfaceToken(interface_descriptor)) != OK || |
| // (status = data.writeInt32(function_input)) != OK) { |
| // // We failed to write into the memory of our local parcel? |
| // } |
| // if ((status = remote()->transact(transaction, data, &reply)) != OK) { |
| // // Something has gone wrong in the binder driver or libbinder. |
| // } |
| // if ((status = remote_exception.readFromParcel(reply)) != OK) { |
| // // The remote didn't correctly write the exception header to the |
| // // reply. |
| // } |
| // if (!remote_exception.isOk()) { |
| // // The transaction went through correctly, but the remote reported an |
| // // exception during handling. |
| // } |
| // |
| class Status final { |
| public: |
| // Keep the exception codes in sync with android/os/Parcel.java. |
| enum Exception { |
| EX_NONE = 0, |
| EX_SECURITY = -1, |
| EX_BAD_PARCELABLE = -2, |
| EX_ILLEGAL_ARGUMENT = -3, |
| EX_NULL_POINTER = -4, |
| EX_ILLEGAL_STATE = -5, |
| EX_NETWORK_MAIN_THREAD = -6, |
| EX_UNSUPPORTED_OPERATION = -7, |
| EX_SERVICE_SPECIFIC = -8, |
| EX_PARCELABLE = -9, |
| |
| // This is special and Java specific; see Parcel.java. |
| EX_HAS_REPLY_HEADER = -128, |
| // This is special, and indicates to C++ binder proxies that the |
| // transaction has failed at a low level. |
| EX_TRANSACTION_FAILED = -129, |
| }; |
| |
| // A more readable alias for the default constructor. |
| static Status ok(); |
| |
| // Authors should explicitly pick whether their integer is: |
| // - an exception code (EX_* above) |
| // - service specific error code |
| // - status_t |
| // |
| // Prefer a generic exception code when possible, then a service specific |
| // code, and finally a status_t for low level failures or legacy support. |
| // Exception codes and service specific errors map to nicer exceptions for |
| // Java clients. |
| static Status fromExceptionCode(int32_t exceptionCode); |
| static Status fromExceptionCode(int32_t exceptionCode, |
| const String8& message); |
| static Status fromExceptionCode(int32_t exceptionCode, |
| const char* message); |
| |
| static Status fromServiceSpecificError(int32_t serviceSpecificErrorCode); |
| static Status fromServiceSpecificError(int32_t serviceSpecificErrorCode, |
| const String8& message); |
| static Status fromServiceSpecificError(int32_t serviceSpecificErrorCode, |
| const char* message); |
| |
| static Status fromStatusT(status_t status); |
| |
| static std::string exceptionToString(status_t exceptionCode); |
| |
| Status() = default; |
| ~Status() = default; |
| |
| // Status objects are copyable and contain just simple data. |
| Status(const Status& status) = default; |
| Status(Status&& status) = default; |
| Status& operator=(const Status& status) = default; |
| |
| // Bear in mind that if the client or service is a Java endpoint, this |
| // is not the logic which will provide/interpret the data here. |
| status_t readFromParcel(const Parcel& parcel); |
| status_t writeToParcel(Parcel* parcel) const; |
| |
| // Set one of the pre-defined exception types defined above. |
| void setException(int32_t ex, const String8& message); |
| // Set a service specific exception with error code. |
| void setServiceSpecificError(int32_t errorCode, const String8& message); |
| // Setting a |status| != OK causes generated code to return |status| |
| // from Binder transactions, rather than writing an exception into the |
| // reply Parcel. This is the least preferable way of reporting errors. |
| void setFromStatusT(status_t status); |
| |
| // Get information about an exception. |
| int32_t exceptionCode() const { return mException; } |
| const String8& exceptionMessage() const { return mMessage; } |
| status_t transactionError() const { |
| return mException == EX_TRANSACTION_FAILED ? mErrorCode : OK; |
| } |
| int32_t serviceSpecificErrorCode() const { |
| return mException == EX_SERVICE_SPECIFIC ? mErrorCode : 0; |
| } |
| |
| bool isOk() const { return mException == EX_NONE; } |
| |
| // For logging. |
| String8 toString8() const; |
| |
| private: |
| Status(int32_t exceptionCode, int32_t errorCode); |
| Status(int32_t exceptionCode, int32_t errorCode, const String8& message); |
| |
| // If |mException| == EX_TRANSACTION_FAILED, generated code will return |
| // |mErrorCode| as the result of the transaction rather than write an |
| // exception to the reply parcel. |
| // |
| // Otherwise, we always write |mException| to the parcel. |
| // If |mException| != EX_NONE, we write |mMessage| as well. |
| // If |mException| == EX_SERVICE_SPECIFIC we write |mErrorCode| as well. |
| int32_t mException = EX_NONE; |
| int32_t mErrorCode = 0; |
| String8 mMessage; |
| }; // class Status |
| |
| // For gtest output logging |
| std::stringstream& operator<< (std::stringstream& stream, const Status& s); |
| |
| } // namespace binder |
| } // namespace android |
| |
| #endif // ANDROID_BINDER_STATUS_H |