Process FuseAppLoop messages in Handler.Callback (5c2688a8) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/os/FuseAppLoop.java

+123 −83

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@ import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.os.ProxyFileDescriptorCallback;
		import android.os.Handler;
		import android.os.Message;
		import android.os.ParcelFileDescriptor;
		import android.system.ErrnoException;
		import android.system.OsConstants;
		@@ -28,10 +29,11 @@ import android.util.SparseArray;
		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.util.Preconditions;
		import java.util.HashMap;
		import java.util.LinkedList;
		import java.util.Map;
		import java.util.concurrent.ThreadFactory;

		public class FuseAppLoop {
		public class FuseAppLoop implements Handler.Callback {
		private static final String TAG = "FuseAppLoop";
		private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
		public static final int ROOT_INODE = 1;
		@@ -43,13 +45,11 @@ public class FuseAppLoop {
		}
		};
		private static final int FUSE_OK = 0;
		private static final int ARGS_POOL_SIZE = 50;

		private final Object mLock = new Object();
		private final int mMountPointId;
		private final Thread mThread;
		private final Handler mDefaultHandler;

		private static final int CMD_FSYNC = 1;

		@GuardedBy("mLock")
		private final SparseArray<CallbackEntry> mCallbackMap = new SparseArray<>();
		@@ -57,6 +57,9 @@ public class FuseAppLoop {
		@GuardedBy("mLock")
		private final BytesMap mBytesMap = new BytesMap();

		@GuardedBy("mLock")
		private final LinkedList<Args> mArgsPool = new LinkedList<>();

		/**
		* Sequential number can be used as file name and inode in AppFuse.
		* 0 is regarded as an error, 1 is mount point. So we start the number from 2.
		@@ -83,7 +86,6 @@ public class FuseAppLoop {
		}
		});
		mThread.start();
		mDefaultHandler = null;
		}

		public int registerCallback(@NonNull ProxyFileDescriptorCallback callback,
		@@ -110,7 +112,8 @@ public class FuseAppLoop {
		break;
		}
		}
		mCallbackMap.put(id, new CallbackEntry(callback, handler));
		mCallbackMap.put(id, new CallbackEntry(
		callback, new Handler(handler.getLooper(), this)));
		return id;
		}
		}
		@@ -137,22 +140,25 @@ public class FuseAppLoop {
		// Defined in FuseBuffer.h
		private static final int FUSE_MAX_WRITE = 256 * 1024;

		// Called by JNI.
		@SuppressWarnings("unused")
		private void onCommand(int command, long unique, long inode, long offset, int size,
		byte[] data) {
		synchronized(mLock) {
		try {
		final CallbackEntry entry = getCallbackEntryOrThrowLocked(inode);
		entry.postRunnable(() -> {
		@Override
		public boolean handleMessage(Message msg) {
		final Args args = (Args) msg.obj;
		final CallbackEntry entry = args.entry;
		final long inode = args.inode;
		final long unique = args.unique;
		final int size = args.size;
		final long offset = args.offset;
		final byte[] data = args.data;

		try {
		switch (command) {
		switch (msg.what) {
		case FUSE_LOOKUP: {
		final long fileSize = entry.callback.onGetSize();
		synchronized (mLock) {
		if (mInstance != 0) {
		native_replyLookup(mInstance, unique, inode, fileSize);
		}
		recycleLocked(args);
		}
		break;
		}
		@@ -162,15 +168,18 @@ public class FuseAppLoop {
		if (mInstance != 0) {
		native_replyGetAttr(mInstance, unique, inode, fileSize);
		}
		recycleLocked(args);
		}
		break;
		}
		case FUSE_READ:
		final int readSize = entry.callback.onRead(offset, size, data);
		final int readSize = entry.callback.onRead(
		offset, size, data);
		synchronized (mLock) {
		if (mInstance != 0) {
		native_replyRead(mInstance, unique, readSize, data);
		}
		recycleLocked(args);
		}
		break;
		case FUSE_WRITE:
		@@ -179,6 +188,7 @@ public class FuseAppLoop {
		if (mInstance != 0) {
		native_replyWrite(mInstance, unique, writeSize);
		}
		recycleLocked(args);
		}
		break;
		case FUSE_FSYNC:
		@@ -187,6 +197,7 @@ public class FuseAppLoop {
		if (mInstance != 0) {
		native_replySimple(mInstance, unique, FUSE_OK);
		}
		recycleLocked(args);
		}
		break;
		case FUSE_RELEASE:
		@@ -196,19 +207,46 @@ public class FuseAppLoop {
		native_replySimple(mInstance, unique, FUSE_OK);
		}
		mBytesMap.stopUsing(entry.getThreadId());
		recycleLocked(args);
		}
		break;
		default:
		throw new IllegalArgumentException(
		"Unknown FUSE command: " + command);
		throw new IllegalArgumentException("Unknown FUSE command: " + msg.what);
		}
		} catch (Exception error) {
		synchronized (mLock) {
		Log.e(TAG, "", error);
		replySimple(unique, getError(error));
		replySimpleLocked(unique, getError(error));
		recycleLocked(args);
		}
		});
		} catch (ErrnoException error) {
		Log.e(TAG, "", error);
		}

		return true;
		}

		// Called by JNI.
		@SuppressWarnings("unused")
		private void onCommand(int command, long unique, long inode, long offset, int size,
		byte[] data) {
		synchronized (mLock) {
		try {
		final Args args;
		if (mArgsPool.size() == 0) {
		args = new Args();
		} else {
		args = mArgsPool.pop();
		}
		args.unique = unique;
		args.inode = inode;
		args.offset = offset;
		args.size = size;
		args.data = data;
		args.entry = getCallbackEntryOrThrowLocked(inode);
		if (!args.entry.handler.sendMessage(
		Message.obtain(args.entry.handler, command, 0, 0, args))) {
		throw new ErrnoException("onCommand", OsConstants.EBADF);
		}
		} catch (Exception error) {
		replySimpleLocked(unique, getError(error));
		}
		}
		@@ -253,9 +291,9 @@ public class FuseAppLoop {
		return entry;
		}

		private void replySimple(long unique, int result) {
		synchronized (mLock) {
		replySimpleLocked(unique, result);
		private void recycleLocked(Args args) {
		if (mArgsPool.size() < ARGS_POOL_SIZE) {
		mArgsPool.add(args);
		}
		}

		@@ -296,13 +334,6 @@ public class FuseAppLoop {
		long getThreadId() {
		return handler.getLooper().getThread().getId();
		}

		void postRunnable(Runnable runnable) throws ErrnoException {
		final boolean result = handler.post(runnable);
		if (!result) {
		throw new ErrnoException("postRunnable", OsConstants.EBADF);
		}
		}
		}

		/**
		@@ -342,4 +373,13 @@ public class FuseAppLoop {
		mEntries.clear();
		}
		}

		private static class Args {
		long unique;
		long inode;
		long offset;
		int size;
		byte[] data;
		CallbackEntry entry;
		}
		}