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/*
* Copyright (C) 2008 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_HARDWARE_IBINDER_H
#define ANDROID_HARDWARE_IBINDER_H
#include <functional>
#include <utils/Errors.h>
#include <utils/RefBase.h>
#include <utils/String16.h>
// WARNING: this code is part of libhwbinder, a fork of libbinder. Generally,
// this means that it is only relevant to HIDL. Any AIDL- or libbinder-specific
// code should not try to use these things.
// ---------------------------------------------------------------------------
namespace android {
namespace hardware {
class BHwBinder;
class BpHwBinder;
class IInterface;
class Parcel;
/**
* Base class and low-level protocol for a remotable object.
* You can derive from this class to create an object for which other
* processes can hold references to it. Communication between processes
* (method calls, property get and set) is down through a low-level
* protocol implemented on top of the transact() API.
*/
class IBinder : public virtual RefBase
{
public:
using TransactCallback = std::function<void(Parcel&)>;
enum {
/* It is very important that these values NEVER change. These values
* must remain unchanged over the lifetime of android. This is
* because the framework on a device will be updated independently of
* the hals on a device. If the hals are compiled with one set of
* transaction values, and the framework with another, then the
* interface between them will be destroyed, and the device will not
* work.
*/
/////////////////// User defined transactions
FIRST_CALL_TRANSACTION = 0x00000001,
LAST_CALL_TRANSACTION = 0x0effffff,
/////////////////// HIDL reserved
#define B_PACK_CHARS_USER(c1, c2, c3, c4) \
((((c1)<<24)) | (((c2)<<16)) | (((c3)<<8)) | (c4))
FIRST_HIDL_TRANSACTION = 0x0f000000,
HIDL_PING_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'P', 'N', 'G'),
HIDL_DESCRIPTOR_CHAIN_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'C', 'H', 'N'),
HIDL_GET_DESCRIPTOR_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'D', 'S', 'C'),
HIDL_SYSPROPS_CHANGED_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'S', 'Y', 'S'),
HIDL_LINK_TO_DEATH_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'L', 'T', 'D'),
HIDL_UNLINK_TO_DEATH_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'U', 'T', 'D'),
HIDL_SET_HAL_INSTRUMENTATION_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'I', 'N', 'T'),
HIDL_GET_REF_INFO_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'R', 'E', 'F'),
HIDL_DEBUG_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'D', 'B', 'G'),
HIDL_HASH_CHAIN_TRANSACTION = B_PACK_CHARS_USER(0x0f, 'H', 'S', 'H'),
#undef B_PACK_CHARS_USER
LAST_HIDL_TRANSACTION = 0x0fffffff,
// Corresponds to TF_ONE_WAY -- an asynchronous call.
FLAG_ONEWAY = 0x00000001,
// Corresponds to TF_CLEAR_BUF -- clear transaction buffers after call
// is made
FLAG_CLEAR_BUF = 0x00000020,
};
IBinder();
virtual status_t transact( uint32_t code,
const Parcel& data,
Parcel* reply,
uint32_t flags = 0,
TransactCallback callback = nullptr) = 0;
class DeathRecipient : public virtual RefBase
{
public:
virtual void binderDied(const wp<IBinder>& who) = 0;
};
/**
* Register the @a recipient for a notification if this binder
* goes away. If this binder object unexpectedly goes away
* (typically because its hosting process has been killed),
* then DeathRecipient::binderDied() will be called with a reference
* to this.
*
* The @a cookie is optional -- if non-NULL, it should be a
* memory address that you own (that is, you know it is unique).
*
* @note You will only receive death notifications for remote binders,
* as local binders by definition can't die without you dying as well.
* Trying to use this function on a local binder will result in an
* INVALID_OPERATION code being returned and nothing happening.
*
* @note This link always holds a weak reference to its recipient.
*
* @note You will only receive a weak reference to the dead
* binder. You should not try to promote this to a strong reference.
* (Nor should you need to, as there is nothing useful you can
* directly do with it now that it has passed on.)
*/
virtual status_t linkToDeath(const sp<DeathRecipient>& recipient,
void* cookie = nullptr,
uint32_t flags = 0) = 0;
/**
* Remove a previously registered death notification.
* The @a recipient will no longer be called if this object
* dies. The @a cookie is optional. If non-NULL, you can
* supply a NULL @a recipient, and the recipient previously
* added with that cookie will be unlinked.
*/
virtual status_t unlinkToDeath( const wp<DeathRecipient>& recipient,
void* cookie = nullptr,
uint32_t flags = 0,
wp<DeathRecipient>* outRecipient = nullptr) = 0;
virtual bool checkSubclass(const void* subclassID) const;
typedef void (*object_cleanup_func)(const void* id, void* obj, void* cleanupCookie);
/**
* This object is attached for the lifetime of this binder object. When
* this binder object is destructed, the cleanup function of all attached
* objects are invoked with their respective objectID, object, and
* cleanupCookie. Access to these APIs can be made from multiple threads,
* but calls from different threads are allowed to be interleaved.
*/
virtual void attachObject( const void* objectID,
void* object,
void* cleanupCookie,
object_cleanup_func func) = 0;
/**
* Returns object attached with attachObject.
*/
virtual void* findObject(const void* objectID) const = 0;
/**
* WARNING: this API does not call the cleanup function for legacy reasons.
* It also does not return void* for legacy reasons. If you need to detach
* an object and destroy it, there are two options:
* - if you can, don't call detachObject and instead wait for the destructor
* to clean it up.
* - manually retrieve and destruct the object (if multiple of your threads
* are accessing these APIs, you must guarantee that attachObject isn't
* called after findObject and before detachObject is called).
*/
virtual void detachObject(const void* objectID) = 0;
virtual BHwBinder* localBinder();
virtual BpHwBinder* remoteBinder();
protected:
virtual ~IBinder();
private:
};
} // namespace hardware
} // namespace android
// ---------------------------------------------------------------------------
#endif // ANDROID_HARDWARE_IBINDER_H