Allow connections to multiple zygotes. (4444dcd0) · Commits · e / os / android_frameworks_base

core/java/android/os/Process.java

+201 −116

Original line number	Diff line number	Diff line
		@@ -19,15 +19,15 @@ package android.os;
		import android.net.LocalSocket;
		import android.net.LocalSocketAddress;
		import android.util.Log;

		import com.android.internal.os.Zygote;

		import java.io.BufferedWriter;
		import java.io.DataInputStream;
		import java.io.IOException;
		import java.io.OutputStreamWriter;
		import java.nio.charset.StandardCharsets;
		import java.util.ArrayList;

		import java.util.Arrays;
		import java.util.List;
		import libcore.io.Libcore;

		/package/ class ZygoteStartFailedEx extends Exception {
		@@ -48,17 +48,7 @@ public class Process {

		private static final String ZYGOTE_SOCKET = "zygote";

		/**
		* Name of a process for running the platform's media services.
		* {@hide}
		*/
		public static final String ANDROID_SHARED_MEDIA = "com.android.process.media";

		/**
		* Name of the process that Google content providers can share.
		* {@hide}
		*/
		public static final String GOOGLE_SHARED_APP_CONTENT = "com.google.process.content";
		private static final String SECONDARY_ZYGOTE_SOCKET = "zygote_secondary";

		/**
		* Defines the UID/GID under which system code runs.
		@@ -346,14 +336,111 @@ public class Process {
		public static final int SIGNAL_KILL = 9;
		public static final int SIGNAL_USR1 = 10;

		// State for communicating with zygote process
		/**
		* State for communicating with the zygote process.
		*/
		static class ZygoteState {
		final LocalSocket socket;
		final DataInputStream inputStream;
		final BufferedWriter writer;
		final List<String> abiList;

		boolean mClosed;

		private ZygoteState(LocalSocket socket, DataInputStream inputStream,
		BufferedWriter writer, List<String> abiList) {
		this.socket = socket;
		this.inputStream = inputStream;
		this.writer = writer;
		this.abiList = abiList;
		}

		static ZygoteState connect(String socketAddress, int tries) throws ZygoteStartFailedEx {
		LocalSocket zygoteSocket = null;
		DataInputStream zygoteInputStream = null;
		BufferedWriter zygoteWriter = null;

		/*
		* See bug #811181: Sometimes runtime can make it up before zygote.
		* Really, we'd like to do something better to avoid this condition,
		* but for now just wait a bit...
		*
		* TODO: This bug was filed in 2007. Get rid of this code. The zygote
		* forks the system_server so it shouldn't be possible for the zygote
		* socket to be brought up after the system_server is.
		*/
		for (int i = 0; i < tries; i++) {
		if (i > 0) {
		try {
		Log.i("Zygote", "Zygote not up yet, sleeping...");
		Thread.sleep(ZYGOTE_RETRY_MILLIS);
		} catch (InterruptedException ex) {
		throw new ZygoteStartFailedEx(ex);
		}
		}

		try {
		zygoteSocket = new LocalSocket();
		zygoteSocket.connect(new LocalSocketAddress(socketAddress,
		LocalSocketAddress.Namespace.RESERVED));

		zygoteInputStream = new DataInputStream(zygoteSocket.getInputStream());

		static LocalSocket sZygoteSocket;
		static DataInputStream sZygoteInputStream;
		static BufferedWriter sZygoteWriter;
		zygoteWriter = new BufferedWriter(new OutputStreamWriter(
		zygoteSocket.getOutputStream()), 256);
		break;
		} catch (IOException ex) {
		if (zygoteSocket != null) {
		try {
		zygoteSocket.close();
		} catch (IOException ex2) {
		Log.e(LOG_TAG,"I/O exception on close after exception", ex2);
		}
		}

		zygoteSocket = null;
		}
		}

		if (zygoteSocket == null) {
		throw new ZygoteStartFailedEx("connect failed");
		}

		String abiListString = getAbiList(zygoteWriter, zygoteInputStream);
		Log.i("Zygote", "Process: zygote socket opened, supported ABIS: " + abiListString);

		return new ZygoteState(zygoteSocket, zygoteInputStream, zygoteWriter,
		Arrays.asList(abiListString.split(",")));
		}

		boolean matches(String abi) {
		return abiList.contains(abi);
		}

		/** true if previous zygote open failed */
		static boolean sPreviousZygoteOpenFailed;
		void close() {
		try {
		socket.close();
		} catch (IOException ex) {
		Log.e(LOG_TAG,"I/O exception on routine close", ex);
		}

		mClosed = true;
		}

		boolean isClosed() {
		return mClosed;
		}
		}

		/**
		* The state of the connection to the primary zygote.
		*/
		static ZygoteState primaryZygoteState;

		/**
		* The state of the connection to the secondary zygote.
		*/
		static ZygoteState secondaryZygoteState;

		/**
		* Start a new process.
		@@ -395,7 +482,9 @@ public class Process {
		String[] zygoteArgs) {
		try {
		return startViaZygote(processClass, niceName, uid, gid, gids,
		debugFlags, mountExternal, targetSdkVersion, seInfo, zygoteArgs);
		debugFlags, mountExternal, targetSdkVersion, seInfo,
		null, /* zygoteAbi TODO: Replace this with the real ABI */
		zygoteArgs);
		} catch (ZygoteStartFailedEx ex) {
		Log.e(LOG_TAG,
		"Starting VM process through Zygote failed");
		@@ -408,78 +497,31 @@ public class Process {
		static final int ZYGOTE_RETRY_MILLIS = 500;

		/**
		* Tries to open socket to Zygote process if not already open. If
		* already open, does nothing. May block and retry.
		* Queries the zygote for the list of ABIS it supports.
		*
		* @throws ZygoteStartFailedEx if the query failed.
		*/
		private static void openZygoteSocketIfNeeded()
		private static String getAbiList(BufferedWriter writer, DataInputStream inputStream)
		throws ZygoteStartFailedEx {

		int retryCount;

		if (sPreviousZygoteOpenFailed) {
		/*
		* If we've failed before, expect that we'll fail again and
		* don't pause for retries.
		*/
		retryCount = 0;
		} else {
		retryCount = 10;
		}

		/*
		* See bug #811181: Sometimes runtime can make it up before zygote.
		* Really, we'd like to do something better to avoid this condition,
		* but for now just wait a bit...
		*/
		for (int retry = 0
		; (sZygoteSocket == null) && (retry < (retryCount + 1))
		; retry++ ) {

		if (retry > 0) {
		try {
		Log.i("Zygote", "Zygote not up yet, sleeping...");
		Thread.sleep(ZYGOTE_RETRY_MILLIS);
		} catch (InterruptedException ex) {
		// should never happen
		}
		}

		try {
		sZygoteSocket = new LocalSocket();

		sZygoteSocket.connect(new LocalSocketAddress(ZYGOTE_SOCKET,
		LocalSocketAddress.Namespace.RESERVED));

		sZygoteInputStream
		= new DataInputStream(sZygoteSocket.getInputStream());

		sZygoteWriter =
		new BufferedWriter(
		new OutputStreamWriter(
		sZygoteSocket.getOutputStream()),
		256);

		Log.i("Zygote", "Process: zygote socket opened");

		sPreviousZygoteOpenFailed = false;
		break;
		} catch (IOException ex) {
		if (sZygoteSocket != null) {
		try {
		sZygoteSocket.close();
		} catch (IOException ex2) {
		Log.e(LOG_TAG,"I/O exception on close after exception",
		ex2);
		}
		}

		sZygoteSocket = null;
		}
		}

		if (sZygoteSocket == null) {
		sPreviousZygoteOpenFailed = true;
		throw new ZygoteStartFailedEx("connect failed");
		// Each query starts with the argument count (1 in this case)
		writer.write("1");
		// ... followed by a new-line.
		writer.newLine();
		// ... followed by our only argument.
		writer.write("--query-abi-list");
		writer.newLine();
		writer.flush();

		// The response is a length prefixed stream of ASCII bytes.
		int numBytes = inputStream.readInt();
		byte[] bytes = new byte[numBytes];
		inputStream.readFully(bytes);

		return new String(bytes, StandardCharsets.US_ASCII);
		} catch (IOException ioe) {
		throw new ZygoteStartFailedEx(ioe);
		}
		}

		@@ -487,14 +529,12 @@ public class Process {
		* Sends an argument list to the zygote process, which starts a new child
		* and returns the child's pid. Please note: the present implementation
		* replaces newlines in the argument list with spaces.
		* @param args argument list
		* @return An object that describes the result of the attempt to start the process.
		*
		* @throws ZygoteStartFailedEx if process start failed for any reason
		*/
		private static ProcessStartResult zygoteSendArgsAndGetResult(ArrayList<String> args)
		private static ProcessStartResult zygoteSendArgsAndGetResult(
		ZygoteState zygoteState, ArrayList<String> args)
		throws ZygoteStartFailedEx {
		openZygoteSocketIfNeeded();

		try {
		/**
		* See com.android.internal.os.ZygoteInit.readArgumentList()
		@@ -506,9 +546,11 @@ public class Process {
		* the child or -1 on failure, followed by boolean to
		* indicate whether a wrapper process was used.
		*/
		final BufferedWriter writer = zygoteState.writer;
		final DataInputStream inputStream = zygoteState.inputStream;

		sZygoteWriter.write(Integer.toString(args.size()));
		sZygoteWriter.newLine();
		writer.write(Integer.toString(args.size()));
		writer.newLine();

		int sz = args.size();
		for (int i = 0; i < sz; i++) {
		@@ -517,32 +559,22 @@ public class Process {
		throw new ZygoteStartFailedEx(
		"embedded newlines not allowed");
		}
		sZygoteWriter.write(arg);
		sZygoteWriter.newLine();
		writer.write(arg);
		writer.newLine();
		}

		sZygoteWriter.flush();
		writer.flush();

		// Should there be a timeout on this?
		ProcessStartResult result = new ProcessStartResult();
		result.pid = sZygoteInputStream.readInt();
		result.pid = inputStream.readInt();
		if (result.pid < 0) {
		throw new ZygoteStartFailedEx("fork() failed");
		}
		result.usingWrapper = sZygoteInputStream.readBoolean();
		result.usingWrapper = inputStream.readBoolean();
		return result;
		} catch (IOException ex) {
		try {
		if (sZygoteSocket != null) {
		sZygoteSocket.close();
		}
		} catch (IOException ex2) {
		// we're going to fail anyway
		Log.e(LOG_TAG,"I/O exception on routine close", ex2);
		}

		sZygoteSocket = null;

		zygoteState.close();
		throw new ZygoteStartFailedEx(ex);
		}
		}
		@@ -559,6 +591,7 @@ public class Process {
		* @param debugFlags Additional flags.
		* @param targetSdkVersion The target SDK version for the app.
		* @param seInfo null-ok SELinux information for the new process.
		* @param abi the ABI the process should use.
		* @param extraArgs Additional arguments to supply to the zygote process.
		* @return An object that describes the result of the attempt to start the process.
		* @throws ZygoteStartFailedEx if process start failed for any reason
		@@ -570,6 +603,7 @@ public class Process {
		int debugFlags, int mountExternal,
		int targetSdkVersion,
		String seInfo,
		String abi,
		String[] extraArgs)
		throws ZygoteStartFailedEx {
		synchronized(Process.class) {
		@@ -637,8 +671,59 @@ public class Process {
		}
		}

		return zygoteSendArgsAndGetResult(argsForZygote);
		return zygoteSendArgsAndGetResult(openZygoteSocketIfNeeded(abi), argsForZygote);
		}
		}

		/**
		* Returns the number of times we attempt a connection to the zygote. We
		* sleep for {@link #ZYGOTE_RETRY_MILLIS} milliseconds between each try.
		*
		* This could probably be removed, see TODO in {@code ZygoteState#connect}.
		*/
		private static int getNumTries(ZygoteState state) {
		// Retry 10 times for the first connection to each zygote.
		if (state == null) {
		return 11;
		}

		// This means the connection has already been established, but subsequently
		// closed, possibly due to an IOException. We retry just once if that's the
		// case.
		return 1;
		}

		/**
		* Tries to open socket to Zygote process if not already open. If
		* already open, does nothing. May block and retry.
		*/
		private static ZygoteState openZygoteSocketIfNeeded(String abi) throws ZygoteStartFailedEx {
		if (primaryZygoteState == null \|\| primaryZygoteState.isClosed()) {
		primaryZygoteState = ZygoteState.connect(ZYGOTE_SOCKET, getNumTries(primaryZygoteState));
		}

		// TODO: Revert this temporary change. This is required to test
		// and submit this change ahead of the package manager changes
		// that supply this abi.
		if (abi == null) {
		return primaryZygoteState;
		}

		if (primaryZygoteState.matches(abi)) {
		return primaryZygoteState;
		}

		// The primary zygote didn't match. Try the secondary.
		if (secondaryZygoteState == null \|\| secondaryZygoteState.isClosed()) {
		secondaryZygoteState = ZygoteState.connect(SECONDARY_ZYGOTE_SOCKET,
		getNumTries(secondaryZygoteState));
		}

		if (secondaryZygoteState.matches(abi)) {
		return secondaryZygoteState;
		}

		throw new ZygoteStartFailedEx("Unsupported zygote ABI: " + abi);
		}

		/**