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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (C) 2006 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.
*/
package android.os;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.ActivityManager;
import android.app.AppOpsManager;
import android.util.Log;
import android.util.SparseIntArray;
import com.android.internal.annotations.GuardedBy;
import com.android.internal.os.BinderInternal;
import libcore.util.NativeAllocationRegistry;
import java.io.FileDescriptor;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
/**
* Java proxy for a native IBinder object.
* Allocated and constructed by the native javaObjectforIBinder function. Never allocated
* directly from Java code.
*
* @hide
*/
public final class BinderProxy implements IBinder {
// See android_util_Binder.cpp for the native half of this.
// Assume the process-wide default value when created
volatile boolean mWarnOnBlocking = Binder.sWarnOnBlocking;
private static volatile Binder.ProxyTransactListener sTransactListener = null;
/**
* @see {@link Binder#setProxyTransactListener(listener)}.
*/
public static void setTransactListener(@Nullable Binder.ProxyTransactListener listener) {
sTransactListener = listener;
}
/*
* Map from longs to BinderProxy, retaining only a WeakReference to the BinderProxies.
* We roll our own only because we need to lazily remove WeakReferences during accesses
* to avoid accumulating junk WeakReference objects. WeakHashMap isn't easily usable
* because we want weak values, not keys.
* Our hash table is never resized, but the number of entries is unlimited;
* performance degrades as occupancy increases significantly past MAIN_INDEX_SIZE.
* Not thread-safe. Client ensures there's a single access at a time.
*/
private static final class ProxyMap {
private static final int LOG_MAIN_INDEX_SIZE = 8;
private static final int MAIN_INDEX_SIZE = 1 << LOG_MAIN_INDEX_SIZE;
private static final int MAIN_INDEX_MASK = MAIN_INDEX_SIZE - 1;
// Debuggable builds will throw an AssertionError if the number of map entries exceeds:
private static final int CRASH_AT_SIZE = 20_000;
/**
* We next warn when we exceed this bucket size.
*/
private int mWarnBucketSize = 20;
/**
* Increment mWarnBucketSize by WARN_INCREMENT each time we warn.
*/
private static final int WARN_INCREMENT = 10;
/**
* Hash function tailored to native pointers.
* Returns a value < MAIN_INDEX_SIZE.
*/
private static int hash(long arg) {
return ((int) ((arg >> 2) ^ (arg >> (2 + LOG_MAIN_INDEX_SIZE)))) & MAIN_INDEX_MASK;
}
/**
* Return the total number of pairs in the map.
*/
private int size() {
int size = 0;
for (ArrayList> a : mMainIndexValues) {
if (a != null) {
size += a.size();
}
}
return size;
}
/**
* Return the total number of pairs in the map containing values that have
* not been cleared. More expensive than the above size function.
*/
private int unclearedSize() {
int size = 0;
for (ArrayList> a : mMainIndexValues) {
if (a != null) {
for (WeakReference ref : a) {
if (ref.get() != null) {
++size;
}
}
}
}
return size;
}
/**
* Remove ith entry from the hash bucket indicated by hash.
*/
private void remove(int hash, int index) {
Long[] keyArray = mMainIndexKeys[hash];
ArrayList> valueArray = mMainIndexValues[hash];
int size = valueArray.size(); // KeyArray may have extra elements.
// Move last entry into empty slot, and truncate at end.
if (index != size - 1) {
keyArray[index] = keyArray[size - 1];
valueArray.set(index, valueArray.get(size - 1));
}
valueArray.remove(size - 1);
// Just leave key array entry; it's unused. We only trust the valueArray size.
}
/**
* Look up the supplied key. If we have a non-cleared entry for it, return it.
*/
BinderProxy get(long key) {
int myHash = hash(key);
Long[] keyArray = mMainIndexKeys[myHash];
if (keyArray == null) {
return null;
}
ArrayList> valueArray = mMainIndexValues[myHash];
int bucketSize = valueArray.size();
for (int i = 0; i < bucketSize; ++i) {
long foundKey = keyArray[i];
if (key == foundKey) {
WeakReference wr = valueArray.get(i);
BinderProxy bp = wr.get();
if (bp != null) {
return bp;
} else {
remove(myHash, i);
return null;
}
}
}
return null;
}
private int mRandom; // A counter used to generate a "random" index. World's 2nd worst RNG.
/**
* Add the key-value pair to the map.
* Requires that the indicated key is not already in the map.
*/
void set(long key, @NonNull BinderProxy value) {
int myHash = hash(key);
ArrayList> valueArray = mMainIndexValues[myHash];
if (valueArray == null) {
valueArray = mMainIndexValues[myHash] = new ArrayList<>();
mMainIndexKeys[myHash] = new Long[1];
}
int size = valueArray.size();
WeakReference newWr = new WeakReference<>(value);
// First look for a cleared reference.
// This ensures that ArrayList size is bounded by the maximum occupancy of
// that bucket.
for (int i = 0; i < size; ++i) {
if (valueArray.get(i).get() == null) {
valueArray.set(i, newWr);
Long[] keyArray = mMainIndexKeys[myHash];
keyArray[i] = key;
if (i < size - 1) {
// "Randomly" check one of the remaining entries in [i+1, size), so that
// needlessly long buckets are eventually pruned.
int rnd = Math.floorMod(++mRandom, size - (i + 1));
if (valueArray.get(i + 1 + rnd).get() == null) {
remove(myHash, i + 1 + rnd);
}
}
return;
}
}
valueArray.add(size, newWr);
Long[] keyArray = mMainIndexKeys[myHash];
if (keyArray.length == size) {
// size >= 1, since we initially allocated one element
Long[] newArray = new Long[size + size / 2 + 2];
System.arraycopy(keyArray, 0, newArray, 0, size);
newArray[size] = key;
mMainIndexKeys[myHash] = newArray;
} else {
keyArray[size] = key;
}
if (size >= mWarnBucketSize) {
final int totalSize = size();
Log.v(Binder.TAG, "BinderProxy map growth! bucket size = " + size
+ " total = " + totalSize);
mWarnBucketSize += WARN_INCREMENT;
if (Build.IS_DEBUGGABLE && totalSize >= CRASH_AT_SIZE) {
// Use the number of uncleared entries to determine whether we should
// really report a histogram and crash. We don't want to fundamentally
// change behavior for a debuggable process, so we GC only if we are
// about to crash.
final int totalUnclearedSize = unclearedSize();
if (totalUnclearedSize >= CRASH_AT_SIZE) {
dumpProxyInterfaceCounts();
dumpPerUidProxyCounts();
Runtime.getRuntime().gc();
throw new AssertionError("Binder ProxyMap has too many entries: "
+ totalSize + " (total), " + totalUnclearedSize + " (uncleared), "
+ unclearedSize() + " (uncleared after GC). BinderProxy leak?");
} else if (totalSize > 3 * totalUnclearedSize / 2) {
Log.v(Binder.TAG, "BinderProxy map has many cleared entries: "
+ (totalSize - totalUnclearedSize) + " of " + totalSize
+ " are cleared");
}
}
}
}
private InterfaceCount[] getSortedInterfaceCounts(int maxToReturn) {
if (maxToReturn < 0) {
throw new IllegalArgumentException("negative interface count");
}
Map counts = new HashMap<>();
final ArrayList> proxiesToQuery =
new ArrayList>();
synchronized (sProxyMap) {
for (ArrayList> a : mMainIndexValues) {
if (a != null) {
proxiesToQuery.addAll(a);
}
}
}
// For gathering this debug output, we're making synchronous binder calls
// out of system_server to all processes hosting binder objects it holds a reference to;
// since some of those processes might be frozen, we don't want to block here
// forever. Disable the freezer.
try {
ActivityManager.getService().enableAppFreezer(false);
} catch (RemoteException e) {
Log.e(Binder.TAG, "RemoteException while disabling app freezer");
}
// We run the dump on a separate thread, because there are known cases where
// a process overrides getInterfaceDescriptor() and somehow blocks on it, causing
// the calling thread (usually AMS) to hit the watchdog.
// Do the dumping on a separate thread instead, and give up after a while.
ExecutorService executorService = Executors.newSingleThreadExecutor();
executorService.submit(() -> {
for (WeakReference weakRef : proxiesToQuery) {
BinderProxy bp = weakRef.get();
String key;
if (bp == null) {
key = "";
} else {
try {
key = bp.getInterfaceDescriptor();
if ((key == null || key.isEmpty()) && !bp.isBinderAlive()) {
key = "";
}
} catch (Throwable t) {
key = "";
}
}
Integer i = counts.get(key);
if (i == null) {
counts.put(key, 1);
} else {
counts.put(key, i + 1);
}
}
});
try {
executorService.shutdown();
boolean dumpDone = executorService.awaitTermination(20, TimeUnit.SECONDS);
if (!dumpDone) {
Log.e(Binder.TAG, "Failed to complete binder proxy dump,"
+ " dumping what we have so far.");
}
} catch (InterruptedException e) {
// Ignore
}
try {
ActivityManager.getService().enableAppFreezer(true);
} catch (RemoteException e) {
Log.e(Binder.TAG, "RemoteException while re-enabling app freezer");
}
Map.Entry[] sorted = counts.entrySet().toArray(
new Map.Entry[counts.size()]);
Arrays.sort(sorted, (Map.Entry a, Map.Entry b)
-> b.getValue().compareTo(a.getValue()));
int returnCount = Math.min(maxToReturn, sorted.length);
InterfaceCount[] ifaceCounts = new InterfaceCount[returnCount];
for (int i = 0; i < returnCount; i++) {
ifaceCounts[i] = new InterfaceCount(sorted[i].getKey(), sorted[i].getValue());
}
return ifaceCounts;
}
static final int MAX_NUM_INTERFACES_TO_DUMP = 10;
/**
* Dump a histogram to the logcat. Used to diagnose abnormally large proxy maps.
*/
private void dumpProxyInterfaceCounts() {
final InterfaceCount[] sorted = getSortedInterfaceCounts(MAX_NUM_INTERFACES_TO_DUMP);
Log.v(Binder.TAG, "BinderProxy descriptor histogram "
+ "(top " + Integer.toString(MAX_NUM_INTERFACES_TO_DUMP) + "):");
for (int i = 0; i < sorted.length; i++) {
Log.v(Binder.TAG, " #" + (i + 1) + ": " + sorted[i]);
}
}
/**
* Dump per uid binder proxy counts to the logcat.
*/
private void dumpPerUidProxyCounts() {
SparseIntArray counts = BinderInternal.nGetBinderProxyPerUidCounts();
if (counts.size() == 0) return;
Log.d(Binder.TAG, "Per Uid Binder Proxy Counts:");
for (int i = 0; i < counts.size(); i++) {
final int uid = counts.keyAt(i);
final int binderCount = counts.valueAt(i);
Log.d(Binder.TAG, "UID : " + uid + " count = " + binderCount);
}
}
// Corresponding ArrayLists in the following two arrays always have the same size.
// They contain no empty entries. However WeakReferences in the values ArrayLists
// may have been cleared.
// mMainIndexKeys[i][j] corresponds to mMainIndexValues[i].get(j) .
// The values ArrayList has the proper size(), the corresponding keys array
// is always at least the same size, but may be larger.
// If either a particular keys array, or the corresponding values ArrayList
// are null, then they both are.
private final Long[][] mMainIndexKeys = new Long[MAIN_INDEX_SIZE][];
private final ArrayList>[] mMainIndexValues =
new ArrayList[MAIN_INDEX_SIZE];
}
@GuardedBy("sProxyMap")
private static final ProxyMap sProxyMap = new ProxyMap();
/**
* Simple pair-value class to store number of binder proxy interfaces live in this process.
*/
public static final class InterfaceCount {
private final String mInterfaceName;
private final int mCount;
InterfaceCount(String interfaceName, int count) {
mInterfaceName = interfaceName;
mCount = count;
}
@Override
public String toString() {
return mInterfaceName + " x" + Integer.toString(mCount);
}
}
/**
* Get a sorted array with entries mapping proxy interface names to the number
* of live proxies with those names.
*
* @param num maximum number of proxy interface counts to return. Use
* Integer.MAX_VALUE to retrieve all
* @hide
*/
public static InterfaceCount[] getSortedInterfaceCounts(int num) {
return sProxyMap.getSortedInterfaceCounts(num);
}
/**
* Returns the number of binder proxies held in this process.
* @return number of binder proxies in this process
*/
public static int getProxyCount() {
synchronized (sProxyMap) {
return sProxyMap.size();
}
}
/**
* Dump proxy debug information.
*
* @hide
*/
public static void dumpProxyDebugInfo() {
if (Build.IS_DEBUGGABLE) {
sProxyMap.dumpProxyInterfaceCounts();
sProxyMap.dumpPerUidProxyCounts();
}
}
/**
* Return a BinderProxy for IBinder.
* If we previously returned a BinderProxy bp for the same iBinder, and bp is still
* in use, then we return the same bp.
*
* @param nativeData C++ pointer to (possibly still empty) BinderProxyNativeData.
* Takes ownership of nativeData iff .mNativeData == nativeData, or if
* we exit via an exception. If neither applies, it's the callers responsibility to
* recycle nativeData.
* @param iBinder C++ pointer to IBinder. Does not take ownership of referenced object.
*/
private static BinderProxy getInstance(long nativeData, long iBinder) {
BinderProxy result;
synchronized (sProxyMap) {
try {
result = sProxyMap.get(iBinder);
if (result != null) {
return result;
}
result = new BinderProxy(nativeData);
} catch (Throwable e) {
// We're throwing an exception (probably OOME); don't drop nativeData.
NativeAllocationRegistry.applyFreeFunction(NoImagePreloadHolder.sNativeFinalizer,
nativeData);
throw e;
}
NoImagePreloadHolder.sRegistry.registerNativeAllocation(result, nativeData);
// The registry now owns nativeData, even if registration threw an exception.
sProxyMap.set(iBinder, result);
}
return result;
}
private BinderProxy(long nativeData) {
mNativeData = nativeData;
}
/**
* Guestimate of native memory associated with a BinderProxy.
* This includes the underlying IBinder, associated DeathRecipientList, and KeyedVector
* that points back to us. We guess high since it includes a GlobalRef, which
* may be in short supply.
*/
private static final int NATIVE_ALLOCATION_SIZE = 1000;
// Use a Holder to allow static initialization of BinderProxy in the boot image, and
// to avoid some initialization ordering issues.
private static class NoImagePreloadHolder {
public static final long sNativeFinalizer = getNativeFinalizer();
public static final NativeAllocationRegistry sRegistry = new NativeAllocationRegistry(
BinderProxy.class.getClassLoader(), sNativeFinalizer, NATIVE_ALLOCATION_SIZE);
}
/**
* @return false if the hosting process is gone, otherwise whatever the remote returns
*/
public native boolean pingBinder();
/**
* @return false if the hosting process is gone
*/
public native boolean isBinderAlive();
/**
* Retrieve a local interface - always null in case of a proxy
*/
public IInterface queryLocalInterface(String descriptor) {
return null;
}
/** @hide */
@Override
public native @Nullable IBinder getExtension() throws RemoteException;
/**
* Perform a binder transaction on a proxy.
*
* @param code The action to perform. This should
* be a number between {@link #FIRST_CALL_TRANSACTION} and
* {@link #LAST_CALL_TRANSACTION}.
* @param data Marshalled data to send to the target. Must not be null.
* If you are not sending any data, you must create an empty Parcel
* that is given here.
* @param reply Marshalled data to be received from the target. May be
* null if you are not interested in the return value.
* @param flags Additional operation flags. Either 0 for a normal
* RPC, or {@link #FLAG_ONEWAY} for a one-way RPC.
*
* @return
* @throws RemoteException
*/
public boolean transact(int code, Parcel data, Parcel reply, int flags) throws RemoteException {
Binder.checkParcel(this, code, data, "Unreasonably large binder buffer");
if (mWarnOnBlocking && ((flags & FLAG_ONEWAY) == 0)
&& Binder.sWarnOnBlockingOnCurrentThread.get()) {
// For now, avoid spamming the log by disabling after we've logged
// about this interface at least once
mWarnOnBlocking = false;
if (Build.IS_USERDEBUG) {
// Log this as a WTF on userdebug builds.
Log.wtf(Binder.TAG,
"Outgoing transactions from this process must be FLAG_ONEWAY",
new Throwable());
} else {
Log.w(Binder.TAG,
"Outgoing transactions from this process must be FLAG_ONEWAY",
new Throwable());
}
}
final boolean tracingEnabled = Binder.isTracingEnabled();
if (tracingEnabled) {
final Throwable tr = new Throwable();
Binder.getTransactionTracker().addTrace(tr);
StackTraceElement stackTraceElement = tr.getStackTrace()[1];
Trace.traceBegin(Trace.TRACE_TAG_ALWAYS,
stackTraceElement.getClassName() + "." + stackTraceElement.getMethodName());
}
// Make sure the listener won't change while processing a transaction.
final Binder.ProxyTransactListener transactListener = sTransactListener;
Object session = null;
if (transactListener != null) {
final int origWorkSourceUid = Binder.getCallingWorkSourceUid();
session = transactListener.onTransactStarted(this, code, flags);
// Allow the listener to update the work source uid. We need to update the request
// header if the uid is updated.
final int updatedWorkSourceUid = Binder.getCallingWorkSourceUid();
if (origWorkSourceUid != updatedWorkSourceUid) {
data.replaceCallingWorkSourceUid(updatedWorkSourceUid);
}
}
final AppOpsManager.PausedNotedAppOpsCollection prevCollection =
AppOpsManager.pauseNotedAppOpsCollection();
if ((flags & FLAG_ONEWAY) == 0 && AppOpsManager.isListeningForOpNoted()) {
flags |= FLAG_COLLECT_NOTED_APP_OPS;
}
try {
return transactNative(code, data, reply, flags);
} finally {
AppOpsManager.resumeNotedAppOpsCollection(prevCollection);
if (transactListener != null) {
transactListener.onTransactEnded(session);
}
if (tracingEnabled) {
Trace.traceEnd(Trace.TRACE_TAG_ALWAYS);
}
}
}
/* Returns the native free function */
private static native long getNativeFinalizer();
/**
* See {@link IBinder#getInterfaceDescriptor()}
*/
public native String getInterfaceDescriptor() throws RemoteException;
/**
* Native implementation of transact() for proxies
*/
public native boolean transactNative(int code, Parcel data, Parcel reply,
int flags) throws RemoteException;
/**
* See {@link IBinder#linkToDeath(DeathRecipient, int)}
*/
public native void linkToDeath(DeathRecipient recipient, int flags)
throws RemoteException;
/**
* See {@link IBinder#unlinkToDeath}
*/
public native boolean unlinkToDeath(DeathRecipient recipient, int flags);
/**
* Perform a dump on the remote object
*
* @param fd The raw file descriptor that the dump is being sent to.
* @param args additional arguments to the dump request.
* @throws RemoteException
*/
public void dump(FileDescriptor fd, String[] args) throws RemoteException {
Parcel data = Parcel.obtain();
Parcel reply = Parcel.obtain();
data.writeFileDescriptor(fd);
data.writeStringArray(args);
try {
transact(DUMP_TRANSACTION, data, reply, 0);
reply.readException();
} finally {
data.recycle();
reply.recycle();
}
}
/**
* Perform an asynchronous dump on the remote object
*
* @param fd The raw file descriptor that the dump is being sent to.
* @param args additional arguments to the dump request.
* @throws RemoteException
*/
public void dumpAsync(FileDescriptor fd, String[] args) throws RemoteException {
Parcel data = Parcel.obtain();
Parcel reply = Parcel.obtain();
data.writeFileDescriptor(fd);
data.writeStringArray(args);
try {
transact(DUMP_TRANSACTION, data, reply, FLAG_ONEWAY);
} finally {
data.recycle();
reply.recycle();
}
}
/**
* See {@link IBinder#shellCommand(FileDescriptor, FileDescriptor, FileDescriptor,
* String[], ShellCallback, ResultReceiver)}
*
* @param in The raw file descriptor that an input data stream can be read from.
* @param out The raw file descriptor that normal command messages should be written to.
* @param err The raw file descriptor that command error messages should be written to.
* @param args Command-line arguments.
* @param callback Optional callback to the caller's shell to perform operations in it.
* @param resultReceiver Called when the command has finished executing, with the result code.
* @throws RemoteException
*/
public void shellCommand(FileDescriptor in, FileDescriptor out, FileDescriptor err,
String[] args, ShellCallback callback,
ResultReceiver resultReceiver) throws RemoteException {
Parcel data = Parcel.obtain();
Parcel reply = Parcel.obtain();
data.writeFileDescriptor(in);
data.writeFileDescriptor(out);
data.writeFileDescriptor(err);
data.writeStringArray(args);
ShellCallback.writeToParcel(callback, data);
resultReceiver.writeToParcel(data, 0);
try {
transact(SHELL_COMMAND_TRANSACTION, data, reply, 0);
reply.readException();
} finally {
data.recycle();
reply.recycle();
}
}
private static void sendDeathNotice(DeathRecipient recipient, IBinder binderProxy) {
if (false) {
Log.v("JavaBinder", "sendDeathNotice to " + recipient + " for " + binderProxy);
}
try {
recipient.binderDied(binderProxy);
} catch (RuntimeException exc) {
Log.w("BinderNative", "Uncaught exception from death notification",
exc);
}
}
/**
* C++ pointer to BinderProxyNativeData. That consists of strong pointers to the
* native IBinder object, and a DeathRecipientList.
*/
private final long mNativeData;
}