replicant-frameworks_native/libs/binder/Binder.cpp

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/*
* Copyright (C) 2005 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/Binder.h>
#include <stdatomic.h>
#include <utils/misc.h>
#include <binder/BpBinder.h>
#include <binder/IInterface.h>
#include <binder/Parcel.h>
#include <stdio.h>
namespace android {
// ---------------------------------------------------------------------------
IBinder::IBinder()
: RefBase()
{
}
IBinder::~IBinder()
{
}
// ---------------------------------------------------------------------------
sp<IInterface> IBinder::queryLocalInterface(const String16& /*descriptor*/)
{
return NULL;
}
BBinder* IBinder::localBinder()
{
return NULL;
}
BpBinder* IBinder::remoteBinder()
{
return NULL;
}
bool IBinder::checkSubclass(const void* /*subclassID*/) const
{
return false;
}
// ---------------------------------------------------------------------------
class BBinder::Extras
{
public:
Mutex mLock;
BpBinder::ObjectManager mObjects;
};
// ---------------------------------------------------------------------------
BBinder::BBinder()
{
atomic_init(&mExtras, static_cast<uintptr_t>(0));
}
bool BBinder::isBinderAlive() const
{
return true;
}
status_t BBinder::pingBinder()
{
return NO_ERROR;
}
const String16& BBinder::getInterfaceDescriptor() const
{
// This is a local static rather than a global static,
// to avoid static initializer ordering issues.
static String16 sEmptyDescriptor;
ALOGW("reached BBinder::getInterfaceDescriptor (this=%p)", this);
return sEmptyDescriptor;
}
status_t BBinder::transact(
uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
{
data.setDataPosition(0);
status_t err = NO_ERROR;
switch (code) {
case PING_TRANSACTION:
reply->writeInt32(pingBinder());
break;
default:
err = onTransact(code, data, reply, flags);
break;
}
if (reply != NULL) {
reply->setDataPosition(0);
}
return err;
}
status_t BBinder::linkToDeath(
const sp<DeathRecipient>& /*recipient*/, void* /*cookie*/,
uint32_t /*flags*/)
{
return INVALID_OPERATION;
}
status_t BBinder::unlinkToDeath(
const wp<DeathRecipient>& /*recipient*/, void* /*cookie*/,
uint32_t /*flags*/, wp<DeathRecipient>* /*outRecipient*/)
{
return INVALID_OPERATION;
}
status_t BBinder::dump(int /*fd*/, const Vector<String16>& /*args*/)
{
return NO_ERROR;
}
void BBinder::attachObject(
const void* objectID, void* object, void* cleanupCookie,
object_cleanup_func func)
{
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_acquire));
if (!e) {
e = new Extras;
uintptr_t expected = 0;
if (!atomic_compare_exchange_strong_explicit(
&mExtras, &expected,
reinterpret_cast<uintptr_t>(e),
memory_order_release,
memory_order_acquire)) {
delete e;
e = reinterpret_cast<Extras*>(expected); // Filled in by CAS
}
if (e == 0) return; // out of memory
}
AutoMutex _l(e->mLock);
e->mObjects.attach(objectID, object, cleanupCookie, func);
}
// The C11 standard doesn't allow atomic loads from const fields,
// though C++11 does. Fudge it until standards get straightened out.
static inline uintptr_t load_const_atomic(const atomic_uintptr_t* p,
memory_order mo) {
atomic_uintptr_t* non_const_p = const_cast<atomic_uintptr_t*>(p);
return atomic_load_explicit(non_const_p, mo);
}
void* BBinder::findObject(const void* objectID) const
{
Extras* e = reinterpret_cast<Extras*>(
load_const_atomic(&mExtras, memory_order_acquire));
if (!e) return NULL;
AutoMutex _l(e->mLock);
return e->mObjects.find(objectID);
}
void BBinder::detachObject(const void* objectID)
{
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_acquire));
if (!e) return;
AutoMutex _l(e->mLock);
e->mObjects.detach(objectID);
}
BBinder* BBinder::localBinder()
{
return this;
}
BBinder::~BBinder()
{
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_relaxed));
if (e) delete e;
}
status_t BBinder::onTransact(
uint32_t code, const Parcel& data, Parcel* reply, uint32_t /*flags*/)
{
switch (code) {
case INTERFACE_TRANSACTION:
reply->writeString16(getInterfaceDescriptor());
return NO_ERROR;
case DUMP_TRANSACTION: {
int fd = data.readFileDescriptor();
int argc = data.readInt32();
Vector<String16> args;
for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
args.add(data.readString16());
}
return dump(fd, args);
}
case SYSPROPS_TRANSACTION: {
report_sysprop_change();
return NO_ERROR;
}
default:
return UNKNOWN_TRANSACTION;
}
}
// ---------------------------------------------------------------------------
enum {
// This is used to transfer ownership of the remote binder from
// the BpRefBase object holding it (when it is constructed), to the
// owner of the BpRefBase object when it first acquires that BpRefBase.
kRemoteAcquired = 0x00000001
};
BpRefBase::BpRefBase(const sp<IBinder>& o)
: mRemote(o.get()), mRefs(NULL), mState(0)
{
extendObjectLifetime(OBJECT_LIFETIME_WEAK);
if (mRemote) {
mRemote->incStrong(this); // Removed on first IncStrong().
mRefs = mRemote->createWeak(this); // Held for our entire lifetime.
}
}
BpRefBase::~BpRefBase()
{
if (mRemote) {
if (!(mState&kRemoteAcquired)) {
mRemote->decStrong(this);
}
mRefs->decWeak(this);
}
}
void BpRefBase::onFirstRef()
{
android_atomic_or(kRemoteAcquired, &mState);
}
void BpRefBase::onLastStrongRef(const void* /*id*/)
{
if (mRemote) {
mRemote->decStrong(this);
}
}
bool BpRefBase::onIncStrongAttempted(uint32_t /*flags*/, const void* /*id*/)
{
return mRemote ? mRefs->attemptIncStrong(this) : false;
}
// ---------------------------------------------------------------------------
}; // namespace android