Merge "libbinder: Add binder::Status type" am: babed3ea52
am: d352198294
* commit 'd3521982942874f4149ebc686be581d0ff857734':
libbinder: Add binder::Status type
diff --git a/include/binder/Status.h b/include/binder/Status.h
new file mode 100644
index 0000000..04738f8
--- /dev/null
+++ b/include/binder/Status.h
@@ -0,0 +1,121 @@
+/*
+ * 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 <binder/Parcel.h>
+#include <utils/String8.h>
+
+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_TRANSACTION_FAILED = -8,
+
+ // This is special and Java specific; see Parcel.java.
+ EX_HAS_REPLY_HEADER = -128,
+ };
+
+ // Allow authors to explicitly pick whether their integer is a status_t or
+ // exception code.
+ static Status fromExceptionCode(int32_t exception_code);
+ static Status fromStatusT(status_t status);
+ // A more readable alias for the default constructor.
+ static Status ok();
+
+ Status() = default;
+ Status(int32_t exception_code, const String8& message);
+ Status(int32_t exception_code, const char* message);
+
+
+ // Status objects are copyable and contain just simple data.
+ Status(const Status& status) = default;
+ Status(Status&& status) = default;
+ Status& operator=(const Status& status) = default;
+
+ ~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);
+ // A few of the status_t values map to exception codes, but most of them
+ // simply map to "transaction failed."
+ void setFromStatusT(status_t status);
+
+ // Get information about an exception.
+ // Any argument may be given as nullptr.
+ void getException(int32_t* returned_exception,
+ String8* returned_message) const;
+ int32_t exceptionCode() const { return mException; }
+ const String8& exceptionMessage() const { return mMessage; }
+
+ bool isOk() const { return mException == EX_NONE; }
+
+ // For logging.
+ String8 toString8() const;
+
+private:
+ // We always write |mException| to the parcel.
+ // If |mException| != EX_NONE, we write message as well.
+ int32_t mException = EX_NONE;
+ String8 mMessage;
+}; // class Status
+
+} // namespace binder
+} // namespace android
+
+#endif // ANDROID_BINDER_STATUS_H
diff --git a/libs/binder/Android.mk b/libs/binder/Android.mk
index ce29ea6..bd11177 100644
--- a/libs/binder/Android.mk
+++ b/libs/binder/Android.mk
@@ -36,6 +36,7 @@
PermissionCache.cpp \
ProcessState.cpp \
Static.cpp \
+ Status.cpp \
TextOutput.cpp \
LOCAL_PATH:= $(call my-dir)
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index e2dddf0..1b41eae 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -23,6 +23,7 @@
#include <binder/Binder.h>
#include <binder/BpBinder.h>
#include <binder/ProcessState.h>
+#include <binder/Status.h>
#include <binder/TextOutput.h>
#include <errno.h>
@@ -69,9 +70,6 @@
// Note: must be kept in sync with android/os/StrictMode.java's PENALTY_GATHER
#define STRICT_MODE_PENALTY_GATHER (0x40 << 16)
-// Note: must be kept in sync with android/os/Parcel.java's EX_HAS_REPLY_HEADER
-#define EX_HAS_REPLY_HEADER -128
-
// XXX This can be made public if we want to provide
// support for typed data.
struct small_flat_data
@@ -1232,7 +1230,8 @@
status_t Parcel::writeNoException()
{
- return writeInt32(0);
+ binder::Status status;
+ return status.writeToParcel(this);
}
void Parcel::remove(size_t /*start*/, size_t /*amt*/)
@@ -1645,18 +1644,9 @@
int32_t Parcel::readExceptionCode() const
{
- int32_t exception_code = readAligned<int32_t>();
- if (exception_code == EX_HAS_REPLY_HEADER) {
- int32_t header_start = dataPosition();
- int32_t header_size = readAligned<int32_t>();
- // Skip over fat responses headers. Not used (or propagated) in
- // native code
- setDataPosition(header_start + header_size);
- // And fat response headers are currently only used when there are no
- // exceptions, so return no error:
- return 0;
- }
- return exception_code;
+ binder::Status status;
+ status.readFromParcel(*this);
+ return status.exceptionCode();
}
native_handle* Parcel::readNativeHandle() const
diff --git a/libs/binder/Status.cpp b/libs/binder/Status.cpp
new file mode 100644
index 0000000..41fff3d
--- /dev/null
+++ b/libs/binder/Status.cpp
@@ -0,0 +1,133 @@
+/*
+ * 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.
+ */
+
+#include <binder/Status.h>
+
+namespace android {
+namespace binder {
+
+Status Status::fromExceptionCode(int32_t exception_code) {
+ return Status(exception_code, "");
+}
+
+Status Status::fromStatusT(status_t status) {
+ Status ret;
+ ret.setFromStatusT(status);
+ return ret;
+}
+
+Status Status::ok() {
+ return Status();
+}
+
+Status::Status(int32_t exception_code, const String8& message)
+ : mException(exception_code),
+ mMessage(message) {}
+
+Status::Status(int32_t exception_code, const char* message)
+ : mException(exception_code),
+ mMessage(message) {}
+
+status_t Status::readFromParcel(const Parcel& parcel) {
+ status_t status = parcel.readInt32(&mException);
+ if (status != OK) {
+ setFromStatusT(status);
+ return status;
+ }
+
+ // Skip over fat response headers. Not used (or propagated) in native code.
+ if (mException == EX_HAS_REPLY_HEADER) {
+ // Note that the header size includes the 4 byte size field.
+ const int32_t header_start = parcel.dataPosition();
+ int32_t header_size;
+ status = parcel.readInt32(&header_size);
+ if (status != OK) {
+ setFromStatusT(status);
+ return status;
+ }
+ parcel.setDataPosition(header_start + header_size);
+ // And fat response headers are currently only used when there are no
+ // exceptions, so act like there was no error.
+ mException = EX_NONE;
+ }
+
+ if (mException == EX_NONE) {
+ return status;
+ }
+
+ // The remote threw an exception. Get the message back.
+ mMessage = String8(parcel.readString16());
+
+ return status;
+}
+
+status_t Status::writeToParcel(Parcel* parcel) const {
+ status_t status = parcel->writeInt32(mException);
+ if (status != OK) { return status; }
+ if (mException == EX_NONE) {
+ // We have no more information to write.
+ return status;
+ }
+ status = parcel->writeString16(String16(mMessage));
+ return status;
+}
+
+void Status::setFromStatusT(status_t status) {
+ switch (status) {
+ case NO_ERROR:
+ mException = EX_NONE;
+ mMessage.clear();
+ break;
+ case UNEXPECTED_NULL:
+ mException = EX_NULL_POINTER;
+ mMessage.setTo("Unexpected null reference in Parcel");
+ break;
+ default:
+ mException = EX_TRANSACTION_FAILED;
+ mMessage.setTo("Transaction failed");
+ break;
+ }
+}
+
+void Status::setException(int32_t ex, const String8& message) {
+ mException = ex;
+ mMessage.setTo(message);
+}
+
+void Status::getException(int32_t* returned_exception,
+ String8* returned_message) const {
+ if (returned_exception) {
+ *returned_exception = mException;
+ }
+ if (returned_message) {
+ returned_message->setTo(mMessage);
+ }
+}
+
+String8 Status::toString8() const {
+ String8 ret;
+ if (mException == EX_NONE) {
+ ret.append("No error");
+ } else {
+ ret.appendFormat("Status(%d): '", mException);
+ ret.append(String8(mMessage));
+ ret.append("'");
+ }
+ return ret;
+}
+
+} // namespace binder
+} // namespace android
