Allow connections to multiple zygotes.
Adds a new String argument "abi" to Process.start.
This method will now query the zygotes to
determine what ABIs the primary and the secondary
zygote support (the secondary is optional) and dispatch
a fork request over the right zygote connection.
Both zygotes are assumed to be active at all points.
Change-Id: I460319b4481ff1c1666e8172223691820658a35c
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index 4cf8767..7d2d051 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -19,15 +19,15 @@
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 @@
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.
@@ -345,15 +335,112 @@
public static final int SIGNAL_QUIT = 3;
public static final int SIGNAL_KILL = 9;
public static final int SIGNAL_USR1 = 10;
-
- // State for communicating with zygote process
- static LocalSocket sZygoteSocket;
- static DataInputStream sZygoteInputStream;
- static BufferedWriter sZygoteWriter;
+ /**
+ * State for communicating with the zygote process.
+ */
+ static class ZygoteState {
+ final LocalSocket socket;
+ final DataInputStream inputStream;
+ final BufferedWriter writer;
+ final List<String> abiList;
- /** true if previous zygote open failed */
- static boolean sPreviousZygoteOpenFailed;
+ 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());
+
+ 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);
+ }
+
+ 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 @@
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 @@
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 {
+ try {
- int retryCount;
+ // 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();
- if (sPreviousZygoteOpenFailed) {
- /*
- * If we've failed before, expect that we'll fail again and
- * don't pause for retries.
- */
- retryCount = 0;
- } else {
- retryCount = 10;
- }
+ // The response is a length prefixed stream of ASCII bytes.
+ int numBytes = inputStream.readInt();
+ byte[] bytes = new byte[numBytes];
+ inputStream.readFully(bytes);
- /*
- * 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");
+ return new String(bytes, StandardCharsets.US_ASCII);
+ } catch (IOException ioe) {
+ throw new ZygoteStartFailedEx(ioe);
}
}
@@ -487,14 +529,12 @@
* 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 @@
* 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 @@
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 @@
* @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 @@
int debugFlags, int mountExternal,
int targetSdkVersion,
String seInfo,
+ String abi,
String[] extraArgs)
throws ZygoteStartFailedEx {
synchronized(Process.class) {
@@ -637,10 +671,61 @@
}
}
- 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);
+ }
+
/**
* Returns elapsed milliseconds of the time this process has run.
* @return Returns the number of milliseconds this process has return.