Split the zygote logic out of android.os.Process into a new ZygoteProcess class.

There is no functional change. This is to support adding new types of zygotes
that all operate using the same protocol.

Bug: 21643067
(cherry picked from commit 94e824bc1b5f83024b7c9a228a8f2d0cd1347d11)

Merged-In: Ie673ee816cae34ac20ffb8c774ec3e6461c3fd0a
Change-Id: I104e6133a90dc93a9854836b5e92d3cd542163a3

1 files changed, 5 insertions, 356 deletions

diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index f664e70cf7be..6aa9fac8d48b 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -16,34 +16,9 @@
 
 package android.os;
 
-import android.net.LocalSocket;
-import android.net.LocalSocketAddress;
 import android.system.Os;
 import android.util.Log;
-import com.android.internal.os.Zygote;
 import dalvik.system.VMRuntime;
-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;
-
-/*package*/ class ZygoteStartFailedEx extends Exception {
-    ZygoteStartFailedEx(String s) {
-        super(s);
-    }
-
-    ZygoteStartFailedEx(Throwable cause) {
-        super(cause);
-    }
-
-    ZygoteStartFailedEx(String s, Throwable cause) {
-        super(s, cause);
-    }
-}
 
 /**
  * Tools for managing OS processes.
@@ -387,83 +362,11 @@ public class Process {
     private static long sStartUptimeMillis;
 
     /**
-     * State for communicating with the zygote process.
-     *
-     * @hide for internal use only.
-     */
-    public 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;
-        }
-
-        public static ZygoteState connect(String socketAddress) throws IOException {
-            DataInputStream zygoteInputStream = null;
-            BufferedWriter zygoteWriter = null;
-            final LocalSocket zygoteSocket = new LocalSocket();
-
-            try {
-                zygoteSocket.connect(new LocalSocketAddress(socketAddress,
-                        LocalSocketAddress.Namespace.RESERVED));
-
-                zygoteInputStream = new DataInputStream(zygoteSocket.getInputStream());
-
-                zygoteWriter = new BufferedWriter(new OutputStreamWriter(
-                        zygoteSocket.getOutputStream()), 256);
-            } catch (IOException ex) {
-                try {
-                    zygoteSocket.close();
-                } catch (IOException ignore) {
-                }
-
-                throw ex;
-            }
-
-            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);
-        }
-
-        public 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.
+     * State associated with the zygote process.
+     * @hide
      */
-    static ZygoteState secondaryZygoteState;
+    public static final ZygoteProcess zygoteProcess =
+            new ZygoteProcess(ZYGOTE_SOCKET, SECONDARY_ZYGOTE_SOCKET);
 
     /**
      * Start a new process.
@@ -509,263 +412,9 @@ public class Process {
                                   String instructionSet,
                                   String appDataDir,
                                   String[] zygoteArgs) {
-        try {
-            return startViaZygote(processClass, niceName, uid, gid, gids,
+        return zygoteProcess.start(processClass, niceName, uid, gid, gids,
                     debugFlags, mountExternal, targetSdkVersion, seInfo,
                     abi, instructionSet, appDataDir, zygoteArgs);
-        } catch (ZygoteStartFailedEx ex) {
-            Log.e(LOG_TAG,
-                    "Starting VM process through Zygote failed");
-            throw new RuntimeException(
-                    "Starting VM process through Zygote failed", ex);
-        }
-    }
-
-    /** retry interval for opening a zygote socket */
-    static final int ZYGOTE_RETRY_MILLIS = 500;
-
-    /**
-     * Queries the zygote for the list of ABIS it supports.
-     *
-     * @throws ZygoteStartFailedEx if the query failed.
-     */
-    private static String getAbiList(BufferedWriter writer, DataInputStream inputStream)
-            throws IOException {
-        // 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);
-    }
-
-    /**
-     * 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.
-     *
-     * @throws ZygoteStartFailedEx if process start failed for any reason
-     */
-    private static ProcessStartResult zygoteSendArgsAndGetResult(
-            ZygoteState zygoteState, ArrayList<String> args)
-            throws ZygoteStartFailedEx {
-        try {
-            /**
-             * See com.android.internal.os.ZygoteInit.readArgumentList()
-             * Presently the wire format to the zygote process is:
-             * a) a count of arguments (argc, in essence)
-             * b) a number of newline-separated argument strings equal to count
-             *
-             * After the zygote process reads these it will write the pid of
-             * 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;
-
-            writer.write(Integer.toString(args.size()));
-            writer.newLine();
-
-            int sz = args.size();
-            for (int i = 0; i < sz; i++) {
-                String arg = args.get(i);
-                if (arg.indexOf('\n') >= 0) {
-                    throw new ZygoteStartFailedEx(
-                            "embedded newlines not allowed");
-                }
-                writer.write(arg);
-                writer.newLine();
-            }
-
-            writer.flush();
-
-            // Should there be a timeout on this?
-            ProcessStartResult result = new ProcessStartResult();
-            result.pid = inputStream.readInt();
-            if (result.pid < 0) {
-                throw new ZygoteStartFailedEx("fork() failed");
-            }
-            result.usingWrapper = inputStream.readBoolean();
-            return result;
-        } catch (IOException ex) {
-            zygoteState.close();
-            throw new ZygoteStartFailedEx(ex);
-        }
-    }
-
-    /**
-     * Starts a new process via the zygote mechanism.
-     *
-     * @param processClass Class name whose static main() to run
-     * @param niceName 'nice' process name to appear in ps
-     * @param uid a POSIX uid that the new process should setuid() to
-     * @param gid a POSIX gid that the new process shuold setgid() to
-     * @param gids null-ok; a list of supplementary group IDs that the
-     * new process should setgroup() to.
-     * @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 instructionSet null-ok the instruction set to use.
-     * @param appDataDir null-ok the data directory of the app.
-     * @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
-     */
-    private static ProcessStartResult startViaZygote(final String processClass,
-                                  final String niceName,
-                                  final int uid, final int gid,
-                                  final int[] gids,
-                                  int debugFlags, int mountExternal,
-                                  int targetSdkVersion,
-                                  String seInfo,
-                                  String abi,
-                                  String instructionSet,
-                                  String appDataDir,
-                                  String[] extraArgs)
-                                  throws ZygoteStartFailedEx {
-        synchronized(Process.class) {
-            ArrayList<String> argsForZygote = new ArrayList<String>();
-
-            // --runtime-args, --setuid=, --setgid=,
-            // and --setgroups= must go first
-            argsForZygote.add("--runtime-args");
-            argsForZygote.add("--setuid=" + uid);
-            argsForZygote.add("--setgid=" + gid);
-            if ((debugFlags & Zygote.DEBUG_ENABLE_JNI_LOGGING) != 0) {
-                argsForZygote.add("--enable-jni-logging");
-            }
-            if ((debugFlags & Zygote.DEBUG_ENABLE_SAFEMODE) != 0) {
-                argsForZygote.add("--enable-safemode");
-            }
-            if ((debugFlags & Zygote.DEBUG_ENABLE_DEBUGGER) != 0) {
-                argsForZygote.add("--enable-debugger");
-            }
-            if ((debugFlags & Zygote.DEBUG_ENABLE_CHECKJNI) != 0) {
-                argsForZygote.add("--enable-checkjni");
-            }
-            if ((debugFlags & Zygote.DEBUG_GENERATE_DEBUG_INFO) != 0) {
-                argsForZygote.add("--generate-debug-info");
-            }
-            if ((debugFlags & Zygote.DEBUG_ALWAYS_JIT) != 0) {
-                argsForZygote.add("--always-jit");
-            }
-            if ((debugFlags & Zygote.DEBUG_NATIVE_DEBUGGABLE) != 0) {
-                argsForZygote.add("--native-debuggable");
-            }
-            if ((debugFlags & Zygote.DEBUG_ENABLE_ASSERT) != 0) {
-                argsForZygote.add("--enable-assert");
-            }
-            if (mountExternal == Zygote.MOUNT_EXTERNAL_DEFAULT) {
-                argsForZygote.add("--mount-external-default");
-            } else if (mountExternal == Zygote.MOUNT_EXTERNAL_READ) {
-                argsForZygote.add("--mount-external-read");
-            } else if (mountExternal == Zygote.MOUNT_EXTERNAL_WRITE) {
-                argsForZygote.add("--mount-external-write");
-            }
-            argsForZygote.add("--target-sdk-version=" + targetSdkVersion);
-
-            //TODO optionally enable debuger
-            //argsForZygote.add("--enable-debugger");
-
-            // --setgroups is a comma-separated list
-            if (gids != null && gids.length > 0) {
-                StringBuilder sb = new StringBuilder();
-                sb.append("--setgroups=");
-
-                int sz = gids.length;
-                for (int i = 0; i < sz; i++) {
-                    if (i != 0) {
-                        sb.append(',');
-                    }
-                    sb.append(gids[i]);
-                }
-
-                argsForZygote.add(sb.toString());
-            }
-
-            if (niceName != null) {
-                argsForZygote.add("--nice-name=" + niceName);
-            }
-
-            if (seInfo != null) {
-                argsForZygote.add("--seinfo=" + seInfo);
-            }
-
-            if (instructionSet != null) {
-                argsForZygote.add("--instruction-set=" + instructionSet);
-            }
-
-            if (appDataDir != null) {
-                argsForZygote.add("--app-data-dir=" + appDataDir);
-            }
-
-            argsForZygote.add(processClass);
-
-            if (extraArgs != null) {
-                for (String arg : extraArgs) {
-                    argsForZygote.add(arg);
-                }
-            }
-
-            return zygoteSendArgsAndGetResult(openZygoteSocketIfNeeded(abi), argsForZygote);
-        }
-    }
-
-    /**
-     * Tries to establish a connection to the zygote that handles a given {@code abi}. Might block and retry if the
-     * zygote is unresponsive. This method is a no-op if a connection is already open.
-     *
-     * @hide
-     */
-    public static void establishZygoteConnectionForAbi(String abi) {
-        try {
-            openZygoteSocketIfNeeded(abi);
-        } catch (ZygoteStartFailedEx ex) {
-            throw new RuntimeException("Unable to connect to zygote for abi: " + abi, ex);
-        }
-    }
-
-    /**
-     * 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()) {
-            try {
-                primaryZygoteState = ZygoteState.connect(ZYGOTE_SOCKET);
-            } catch (IOException ioe) {
-                throw new ZygoteStartFailedEx("Error connecting to primary zygote", ioe);
-            }
-        }
-
-        if (primaryZygoteState.matches(abi)) {
-            return primaryZygoteState;
-        }
-
-        // The primary zygote didn't match. Try the secondary.
-        if (secondaryZygoteState == null || secondaryZygoteState.isClosed()) {
-            try {
-            secondaryZygoteState = ZygoteState.connect(SECONDARY_ZYGOTE_SOCKET);
-            } catch (IOException ioe) {
-                throw new ZygoteStartFailedEx("Error connecting to secondary zygote", ioe);
-            }
-        }
-
-        if (secondaryZygoteState.matches(abi)) {
-            return secondaryZygoteState;
-        }
-
-        throw new ZygoteStartFailedEx("Unsupported zygote ABI: " + abi);
     }
 
     /**