/*
* Copyright (C) 2007 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 com.android.internal.os;
import static android.system.OsConstants.POLLIN;
import static android.system.OsConstants.S_IRWXG;
import static android.system.OsConstants.S_IRWXO;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.icu.impl.CacheValue;
import android.icu.text.DecimalFormatSymbols;
import android.icu.util.ULocale;
import android.net.LocalServerSocket;
import android.opengl.EGL14;
import android.os.Process;
import android.os.SystemClock;
import android.os.SystemProperties;
import android.os.Trace;
import android.security.keystore.AndroidKeyStoreProvider;
import android.system.ErrnoException;
import android.system.Os;
import android.system.OsConstants;
import android.system.StructPollfd;
import android.text.Hyphenator;
import android.util.EventLog;
import android.util.Log;
import android.webkit.WebViewFactory;
import android.widget.TextView;
import com.android.internal.os.InstallerConnection.InstallerException;
import dalvik.system.DexFile;
import dalvik.system.PathClassLoader;
import dalvik.system.VMRuntime;
import dalvik.system.ZygoteHooks;
import libcore.io.IoUtils;
import java.io.BufferedReader;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.security.Security;
import java.security.Provider;
import java.util.ArrayList;
/**
* Startup class for the zygote process.
*
* Pre-initializes some classes, and then waits for commands on a UNIX domain
* socket. Based on these commands, forks off child processes that inherit
* the initial state of the VM.
*
* Please see {@link ZygoteConnection.Arguments} for documentation on the
* client protocol.
*
* @hide
*/
public class ZygoteInit {
private static final String TAG = "Zygote";
private static final String PROPERTY_DISABLE_OPENGL_PRELOADING = "ro.zygote.disable_gl_preload";
private static final String PROPERTY_RUNNING_IN_CONTAINER = "ro.boot.container";
private static final String ANDROID_SOCKET_PREFIX = "ANDROID_SOCKET_";
private static final int LOG_BOOT_PROGRESS_PRELOAD_START = 3020;
private static final int LOG_BOOT_PROGRESS_PRELOAD_END = 3030;
/** when preloading, GC after allocating this many bytes */
private static final int PRELOAD_GC_THRESHOLD = 50000;
private static final String ABI_LIST_ARG = "--abi-list=";
private static final String SOCKET_NAME_ARG = "--socket-name=";
private static LocalServerSocket sServerSocket;
/**
* Used to pre-load resources. We hold a global reference on it so it
* never gets destroyed.
*/
private static Resources mResources;
/**
* The path of a file that contains classes to preload.
*/
private static final String PRELOADED_CLASSES = "/system/etc/preloaded-classes";
/** Controls whether we should preload resources during zygote init. */
public static final boolean PRELOAD_RESOURCES = true;
/**
* Registers a server socket for zygote command connections
*
* @throws RuntimeException when open fails
*/
private static void registerZygoteSocket(String socketName) {
if (sServerSocket == null) {
int fileDesc;
final String fullSocketName = ANDROID_SOCKET_PREFIX + socketName;
try {
String env = System.getenv(fullSocketName);
fileDesc = Integer.parseInt(env);
} catch (RuntimeException ex) {
throw new RuntimeException(fullSocketName + " unset or invalid", ex);
}
try {
FileDescriptor fd = new FileDescriptor();
fd.setInt$(fileDesc);
sServerSocket = new LocalServerSocket(fd);
} catch (IOException ex) {
throw new RuntimeException(
"Error binding to local socket '" + fileDesc + "'", ex);
}
}
}
/**
* Waits for and accepts a single command connection. Throws
* RuntimeException on failure.
*/
private static ZygoteConnection acceptCommandPeer(String abiList) {
try {
return new ZygoteConnection(sServerSocket.accept(), abiList);
} catch (IOException ex) {
throw new RuntimeException(
"IOException during accept()", ex);
}
}
/**
* Close and clean up zygote sockets. Called on shutdown and on the
* child's exit path.
*/
static void closeServerSocket() {
try {
if (sServerSocket != null) {
FileDescriptor fd = sServerSocket.getFileDescriptor();
sServerSocket.close();
if (fd != null) {
Os.close(fd);
}
}
} catch (IOException ex) {
Log.e(TAG, "Zygote: error closing sockets", ex);
} catch (ErrnoException ex) {
Log.e(TAG, "Zygote: error closing descriptor", ex);
}
sServerSocket = null;
}
/**
* Return the server socket's underlying file descriptor, so that
* ZygoteConnection can pass it to the native code for proper
* closure after a child process is forked off.
*/
static FileDescriptor getServerSocketFileDescriptor() {
return sServerSocket.getFileDescriptor();
}
private static final int UNPRIVILEGED_UID = 9999;
private static final int UNPRIVILEGED_GID = 9999;
private static final int ROOT_UID = 0;
private static final int ROOT_GID = 0;
static void preload() {
Log.d(TAG, "begin preload");
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "BeginIcuCachePinning");
beginIcuCachePinning();
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "PreloadClasses");
preloadClasses();
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "PreloadResources");
preloadResources();
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "PreloadOpenGL");
preloadOpenGL();
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
preloadSharedLibraries();
preloadTextResources();
// Ask the WebViewFactory to do any initialization that must run in the zygote process,
// for memory sharing purposes.
WebViewFactory.prepareWebViewInZygote();
endIcuCachePinning();
warmUpJcaProviders();
Log.d(TAG, "end preload");
}
private static void beginIcuCachePinning() {
// Pin ICU data in memory from this point that would normally be held by soft references.
// Without this, any references created immediately below or during class preloading
// would be collected when the Zygote GC runs in gcAndFinalize().
Log.i(TAG, "Installing ICU cache reference pinning...");
CacheValue.setStrength(CacheValue.Strength.STRONG);
Log.i(TAG, "Preloading ICU data...");
// Explicitly exercise code to cache data apps are likely to need.
ULocale[] localesToPin = { ULocale.ROOT, ULocale.US, ULocale.getDefault() };
for (ULocale uLocale : localesToPin) {
new DecimalFormatSymbols(uLocale);
}
}
private static void endIcuCachePinning() {
// All cache references created by ICU from this point will be soft.
CacheValue.setStrength(CacheValue.Strength.SOFT);
Log.i(TAG, "Uninstalled ICU cache reference pinning...");
}
private static void preloadSharedLibraries() {
Log.i(TAG, "Preloading shared libraries...");
System.loadLibrary("android");
System.loadLibrary("compiler_rt");
System.loadLibrary("jnigraphics");
}
private static void preloadOpenGL() {
if (!SystemProperties.getBoolean(PROPERTY_DISABLE_OPENGL_PRELOADING, false)) {
EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
}
}
private static void preloadTextResources() {
Hyphenator.init();
TextView.preloadFontCache();
}
/**
* Register AndroidKeyStoreProvider and warm up the providers that are already registered.
*
* By doing it here we avoid that each app does it when requesting a service from the
* provider for the first time.
*/
private static void warmUpJcaProviders() {
long startTime = SystemClock.uptimeMillis();
Trace.traceBegin(
Trace.TRACE_TAG_DALVIK, "Starting installation of AndroidKeyStoreProvider");
// AndroidKeyStoreProvider.install() manipulates the list of JCA providers to insert
// preferred providers. Note this is not done via security.properties as the JCA providers
// are not on the classpath in the case of, for example, raw dalvikvm runtimes.
AndroidKeyStoreProvider.install();
Log.i(TAG, "Installed AndroidKeyStoreProvider in "
+ (SystemClock.uptimeMillis() - startTime) + "ms.");
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
startTime = SystemClock.uptimeMillis();
Trace.traceBegin(
Trace.TRACE_TAG_DALVIK, "Starting warm up of JCA providers");
for (Provider p : Security.getProviders()) {
p.warmUpServiceProvision();
}
Log.i(TAG, "Warmed up JCA providers in "
+ (SystemClock.uptimeMillis() - startTime) + "ms.");
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
}
/**
* Performs Zygote process initialization. Loads and initializes
* commonly used classes.
*
* Most classes only cause a few hundred bytes to be allocated, but
* a few will allocate a dozen Kbytes (in one case, 500+K).
*/
private static void preloadClasses() {
final VMRuntime runtime = VMRuntime.getRuntime();
InputStream is;
try {
is = new FileInputStream(PRELOADED_CLASSES);
} catch (FileNotFoundException e) {
Log.e(TAG, "Couldn't find " + PRELOADED_CLASSES + ".");
return;
}
Log.i(TAG, "Preloading classes...");
long startTime = SystemClock.uptimeMillis();
// Drop root perms while running static initializers.
final int reuid = Os.getuid();
final int regid = Os.getgid();
// We need to drop root perms only if we're already root. In the case of "wrapped"
// processes (see WrapperInit), this function is called from an unprivileged uid
// and gid.
boolean droppedPriviliges = false;
if (reuid == ROOT_UID && regid == ROOT_GID) {
try {
Os.setregid(ROOT_GID, UNPRIVILEGED_GID);
Os.setreuid(ROOT_UID, UNPRIVILEGED_UID);
} catch (ErrnoException ex) {
throw new RuntimeException("Failed to drop root", ex);
}
droppedPriviliges = true;
}
// Alter the target heap utilization. With explicit GCs this
// is not likely to have any effect.
float defaultUtilization = runtime.getTargetHeapUtilization();
runtime.setTargetHeapUtilization(0.8f);
try {
BufferedReader br
= new BufferedReader(new InputStreamReader(is), 256);
int count = 0;
String line;
while ((line = br.readLine()) != null) {
// Skip comments and blank lines.
line = line.trim();
if (line.startsWith("#") || line.equals("")) {
continue;
}
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, line);
try {
if (false) {
Log.v(TAG, "Preloading " + line + "...");
}
// Load and explicitly initialize the given class. Use
// Class.forName(String, boolean, ClassLoader) to avoid repeated stack lookups
// (to derive the caller's class-loader). Use true to force initialization, and
// null for the boot classpath class-loader (could as well cache the
// class-loader of this class in a variable).
Class.forName(line, true, null);
count++;
} catch (ClassNotFoundException e) {
Log.w(TAG, "Class not found for preloading: " + line);
} catch (UnsatisfiedLinkError e) {
Log.w(TAG, "Problem preloading " + line + ": " + e);
} catch (Throwable t) {
Log.e(TAG, "Error preloading " + line + ".", t);
if (t instanceof Error) {
throw (Error) t;
}
if (t instanceof RuntimeException) {
throw (RuntimeException) t;
}
throw new RuntimeException(t);
}
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
}
Log.i(TAG, "...preloaded " + count + " classes in "
+ (SystemClock.uptimeMillis()-startTime) + "ms.");
} catch (IOException e) {
Log.e(TAG, "Error reading " + PRELOADED_CLASSES + ".", e);
} finally {
IoUtils.closeQuietly(is);
// Restore default.
runtime.setTargetHeapUtilization(defaultUtilization);
// Fill in dex caches with classes, fields, and methods brought in by preloading.
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "PreloadDexCaches");
runtime.preloadDexCaches();
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
// Bring back root. We'll need it later if we're in the zygote.
if (droppedPriviliges) {
try {
Os.setreuid(ROOT_UID, ROOT_UID);
Os.setregid(ROOT_GID, ROOT_GID);
} catch (ErrnoException ex) {
throw new RuntimeException("Failed to restore root", ex);
}
}
}
}
/**
* Load in commonly used resources, so they can be shared across
* processes.
*
* These tend to be a few Kbytes, but are frequently in the 20-40K
* range, and occasionally even larger.
*/
private static void preloadResources() {
final VMRuntime runtime = VMRuntime.getRuntime();
try {
mResources = Resources.getSystem();
mResources.startPreloading();
if (PRELOAD_RESOURCES) {
Log.i(TAG, "Preloading resources...");
long startTime = SystemClock.uptimeMillis();
TypedArray ar = mResources.obtainTypedArray(
com.android.internal.R.array.preloaded_drawables);
int N = preloadDrawables(ar);
ar.recycle();
Log.i(TAG, "...preloaded " + N + " resources in "
+ (SystemClock.uptimeMillis()-startTime) + "ms.");
startTime = SystemClock.uptimeMillis();
ar = mResources.obtainTypedArray(
com.android.internal.R.array.preloaded_color_state_lists);
N = preloadColorStateLists(ar);
ar.recycle();
Log.i(TAG, "...preloaded " + N + " resources in "
+ (SystemClock.uptimeMillis()-startTime) + "ms.");
if (mResources.getBoolean(
com.android.internal.R.bool.config_freeformWindowManagement)) {
startTime = SystemClock.uptimeMillis();
ar = mResources.obtainTypedArray(
com.android.internal.R.array.preloaded_freeform_multi_window_drawables);
N = preloadDrawables(ar);
ar.recycle();
Log.i(TAG, "...preloaded " + N + " resource in "
+ (SystemClock.uptimeMillis() - startTime) + "ms.");
}
}
mResources.finishPreloading();
} catch (RuntimeException e) {
Log.w(TAG, "Failure preloading resources", e);
}
}
private static int preloadColorStateLists(TypedArray ar) {
int N = ar.length();
for (int i=0; i<N; i++) {
int id = ar.getResourceId(i, 0);
if (false) {
Log.v(TAG, "Preloading resource #" + Integer.toHexString(id));
}
if (id != 0) {
if (mResources.getColorStateList(id, null) == null) {
throw new IllegalArgumentException(
"Unable to find preloaded color resource #0x"
+ Integer.toHexString(id)
+ " (" + ar.getString(i) + ")");
}
}
}
return N;
}
private static int preloadDrawables(TypedArray ar) {
int N = ar.length();
for (int i=0; i<N; i++) {
int id = ar.getResourceId(i, 0);
if (false) {
Log.v(TAG, "Preloading resource #" + Integer.toHexString(id));
}
if (id != 0) {
if (mResources.getDrawable(id, null) == null) {
throw new IllegalArgumentException(
"Unable to find preloaded drawable resource #0x"
+ Integer.toHexString(id)
+ " (" + ar.getString(i) + ")");
}
}
}
return N;
}
/**
* Runs several special GCs to try to clean up a few generations of
* softly- and final-reachable objects, along with any other garbage.
* This is only useful just before a fork().
*/
/*package*/ static void gcAndFinalize() {
final VMRuntime runtime = VMRuntime.getRuntime();
/* runFinalizationSync() lets finalizers be called in Zygote,
* which doesn't have a HeapWorker thread.
*/
System.gc();
runtime.runFinalizationSync();
System.gc();
}
/**
* Finish remaining work for the newly forked system server process.
*/
private static void handleSystemServerProcess(
ZygoteConnection.Arguments parsedArgs)
throws ZygoteInit.MethodAndArgsCaller {
closeServerSocket();
// set umask to 0077 so new files and directories will default to owner-only permissions.
Os.umask(S_IRWXG | S_IRWXO);
if (parsedArgs.niceName != null) {
Process.setArgV0(parsedArgs.niceName);
}
final String systemServerClasspath = Os.getenv("SYSTEMSERVERCLASSPATH");
if (systemServerClasspath != null) {
performSystemServerDexOpt(systemServerClasspath);
}
if (parsedArgs.invokeWith != null) {
String[] args = parsedArgs.remainingArgs;
// If we have a non-null system server class path, we'll have to duplicate the
// existing arguments and append the classpath to it. ART will handle the classpath
// correctly when we exec a new process.
if (systemServerClasspath != null) {
String[] amendedArgs = new String[args.length + 2];
amendedArgs[0] = "-cp";
amendedArgs[1] = systemServerClasspath;
System.arraycopy(parsedArgs.remainingArgs, 0, amendedArgs, 2, parsedArgs.remainingArgs.length);
}
WrapperInit.execApplication(parsedArgs.invokeWith,
parsedArgs.niceName, parsedArgs.targetSdkVersion,
VMRuntime.getCurrentInstructionSet(), null, args);
} else {
ClassLoader cl = null;
if (systemServerClasspath != null) {
cl = createSystemServerClassLoader(systemServerClasspath,
parsedArgs.targetSdkVersion);
Thread.currentThread().setContextClassLoader(cl);
}
/*
* Pass the remaining arguments to SystemServer.
*/
RuntimeInit.zygoteInit(parsedArgs.targetSdkVersion, parsedArgs.remainingArgs, cl);
}
/* should never reach here */
}
/**
* Creates a PathClassLoader for the system server. It also creates
* a shared namespace associated with the classloader to let it access
* platform-private native libraries.
*/
private static PathClassLoader createSystemServerClassLoader(String systemServerClasspath,
int targetSdkVersion) {
String librarySearchPath = System.getProperty("java.library.path");
return PathClassLoaderFactory.createClassLoader(systemServerClasspath,
librarySearchPath,
null /* libraryPermittedPath */,
ClassLoader.getSystemClassLoader(),
targetSdkVersion,
true /* isNamespaceShared */);
}
/**
* Performs dex-opt on the elements of {@code classPath}, if needed. We
* choose the instruction set of the current runtime.
*/
private static void performSystemServerDexOpt(String classPath) {
final String[] classPathElements = classPath.split(":");
final InstallerConnection installer = new InstallerConnection();
installer.waitForConnection();
final String instructionSet = VMRuntime.getRuntime().vmInstructionSet();
try {
String sharedLibraries = "";
for (String classPathElement : classPathElements) {
// System server is fully AOTed and never profiled
// for profile guided compilation.
// TODO: Make this configurable between INTERPRET_ONLY, SPEED, SPACE and EVERYTHING?
int dexoptNeeded;
try {
dexoptNeeded = DexFile.getDexOptNeeded(
classPathElement, instructionSet, "speed",
false /* newProfile */);
} catch (FileNotFoundException ignored) {
// Do not add to the classpath.
Log.w(TAG, "Missing classpath element for system server: " + classPathElement);
continue;
} catch (IOException e) {
// Not fully clear what to do here as we don't know the cause of the
// IO exception. Add to the classpath to be conservative, but don't
// attempt to compile it.
Log.w(TAG, "Error checking classpath element for system server: "
+ classPathElement, e);
dexoptNeeded = DexFile.NO_DEXOPT_NEEDED;
}
if (dexoptNeeded != DexFile.NO_DEXOPT_NEEDED) {
try {
installer.dexopt(classPathElement, Process.SYSTEM_UID, instructionSet,
dexoptNeeded, 0 /*dexFlags*/, "speed", null /*volumeUuid*/,
sharedLibraries);
} catch (InstallerException e) {
// Ignore (but log), we need this on the classpath for fallback mode.
Log.w(TAG, "Failed compiling classpath element for system server: "
+ classPathElement, e);
}
}
if (!sharedLibraries.isEmpty()) {
sharedLibraries += ":";
}
sharedLibraries += classPathElement;
}
} finally {
installer.disconnect();
}
}
/**
* Prepare the arguments and fork for the system server process.
*/
private static boolean startSystemServer(String abiList, String socketName)
throws MethodAndArgsCaller, RuntimeException {
long capabilities = posixCapabilitiesAsBits(
OsConstants.CAP_IPC_LOCK,
OsConstants.CAP_KILL,
OsConstants.CAP_NET_ADMIN,
OsConstants.CAP_NET_BIND_SERVICE,
OsConstants.CAP_NET_BROADCAST,
OsConstants.CAP_NET_RAW,
OsConstants.CAP_SYS_MODULE,
OsConstants.CAP_SYS_NICE,
OsConstants.CAP_SYS_RESOURCE,
OsConstants.CAP_SYS_TIME,
OsConstants.CAP_SYS_TTY_CONFIG
);
/* Containers run without this capability, so avoid setting it in that case */
if (!SystemProperties.getBoolean(PROPERTY_RUNNING_IN_CONTAINER, false)) {
capabilities |= posixCapabilitiesAsBits(OsConstants.CAP_BLOCK_SUSPEND);
}
/* Hardcoded command line to start the system server */
String args[] = {
"--setuid=1000",
"--setgid=1000",
"--setgroups=1001,1002,1003,1004,1005,1006,1007,1008,1009,1010,1018,1021,1032,3001,3002,3003,3006,3007,3009,3010",
"--capabilities=" + capabilities + "," + capabilities,
"--nice-name=system_server",
"--runtime-args",
"com.android.server.SystemServer",
};
ZygoteConnection.Arguments parsedArgs = null;
int pid;
try {
parsedArgs = new ZygoteConnection.Arguments(args);
ZygoteConnection.applyDebuggerSystemProperty(parsedArgs);
ZygoteConnection.applyInvokeWithSystemProperty(parsedArgs);
/* Request to fork the system server process */
pid = Zygote.forkSystemServer(
parsedArgs.uid, parsedArgs.gid,
parsedArgs.gids,
parsedArgs.debugFlags,
null,
parsedArgs.permittedCapabilities,
parsedArgs.effectiveCapabilities);
} catch (IllegalArgumentException ex) {
throw new RuntimeException(ex);
}
/* For child process */
if (pid == 0) {
if (hasSecondZygote(abiList)) {
waitForSecondaryZygote(socketName);
}
handleSystemServerProcess(parsedArgs);
}
return true;
}
/**
* Gets the bit array representation of the provided list of POSIX capabilities.
*/
private static long posixCapabilitiesAsBits(int... capabilities) {
long result = 0;
for (int capability : capabilities) {
if ((capability < 0) || (capability > OsConstants.CAP_LAST_CAP)) {
throw new IllegalArgumentException(String.valueOf(capability));
}
result |= (1L << capability);
}
return result;
}
public static void main(String argv[]) {
// Mark zygote start. This ensures that thread creation will throw
// an error.
ZygoteHooks.startZygoteNoThreadCreation();
try {
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "ZygoteInit");
RuntimeInit.enableDdms();
// Start profiling the zygote initialization.
SamplingProfilerIntegration.start();
boolean startSystemServer = false;
String socketName = "zygote";
String abiList = null;
for (int i = 1; i < argv.length; i++) {
if ("start-system-server".equals(argv[i])) {
startSystemServer = true;
} else if (argv[i].startsWith(ABI_LIST_ARG)) {
abiList = argv[i].substring(ABI_LIST_ARG.length());
} else if (argv[i].startsWith(SOCKET_NAME_ARG)) {
socketName = argv[i].substring(SOCKET_NAME_ARG.length());
} else {
throw new RuntimeException("Unknown command line argument: " + argv[i]);
}
}
if (abiList == null) {
throw new RuntimeException("No ABI list supplied.");
}
registerZygoteSocket(socketName);
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "ZygotePreload");
EventLog.writeEvent(LOG_BOOT_PROGRESS_PRELOAD_START,
SystemClock.uptimeMillis());
preload();
EventLog.writeEvent(LOG_BOOT_PROGRESS_PRELOAD_END,
SystemClock.uptimeMillis());
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
// Finish profiling the zygote initialization.
SamplingProfilerIntegration.writeZygoteSnapshot();
// Do an initial gc to clean up after startup
Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "PostZygoteInitGC");
gcAndFinalize();
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
// Disable tracing so that forked processes do not inherit stale tracing tags from
// Zygote.
Trace.setTracingEnabled(false);
// Zygote process unmounts root storage spaces.
Zygote.nativeUnmountStorageOnInit();
ZygoteHooks.stopZygoteNoThreadCreation();
if (startSystemServer) {
startSystemServer(abiList, socketName);
}
Log.i(TAG, "Accepting command socket connections");
runSelectLoop(abiList);
closeServerSocket();
} catch (MethodAndArgsCaller caller) {
caller.run();
} catch (Throwable ex) {
Log.e(TAG, "Zygote died with exception", ex);
closeServerSocket();
throw ex;
}
}
/**
* Return {@code true} if this device configuration has another zygote.
*
* We determine this by comparing the device ABI list with this zygotes
* list. If this zygote supports all ABIs this device supports, there won't
* be another zygote.
*/
private static boolean hasSecondZygote(String abiList) {
return !SystemProperties.get("ro.product.cpu.abilist").equals(abiList);
}
private static void waitForSecondaryZygote(String socketName) {
String otherZygoteName = Process.ZYGOTE_SOCKET.equals(socketName) ?
Process.SECONDARY_ZYGOTE_SOCKET : Process.ZYGOTE_SOCKET;
while (true) {
try {
final Process.ZygoteState zs = Process.ZygoteState.connect(otherZygoteName);
zs.close();
break;
} catch (IOException ioe) {
Log.w(TAG, "Got error connecting to zygote, retrying. msg= " + ioe.getMessage());
}
try {
Thread.sleep(1000);
} catch (InterruptedException ie) {
}
}
}
/**
* Runs the zygote process's select loop. Accepts new connections as
* they happen, and reads commands from connections one spawn-request's
* worth at a time.
*
* @throws MethodAndArgsCaller in a child process when a main() should
* be executed.
*/
private static void runSelectLoop(String abiList) throws MethodAndArgsCaller {
ArrayList<FileDescriptor> fds = new ArrayList<FileDescriptor>();
ArrayList<ZygoteConnection> peers = new ArrayList<ZygoteConnection>();
fds.add(sServerSocket.getFileDescriptor());
peers.add(null);
while (true) {
StructPollfd[] pollFds = new StructPollfd[fds.size()];
for (int i = 0; i < pollFds.length; ++i) {
pollFds[i] = new StructPollfd();
pollFds[i].fd = fds.get(i);
pollFds[i].events = (short) POLLIN;
}
try {
Os.poll(pollFds, -1);
} catch (ErrnoException ex) {
throw new RuntimeException("poll failed", ex);
}
for (int i = pollFds.length - 1; i >= 0; --i) {
if ((pollFds[i].revents & POLLIN) == 0) {
continue;
}
if (i == 0) {
ZygoteConnection newPeer = acceptCommandPeer(abiList);
peers.add(newPeer);
fds.add(newPeer.getFileDesciptor());
} else {
boolean done = peers.get(i).runOnce();
if (done) {
peers.remove(i);
fds.remove(i);
}
}
}
}
}
/**
* Class not instantiable.
*/
private ZygoteInit() {
}
/**
* Helper exception class which holds a method and arguments and
* can call them. This is used as part of a trampoline to get rid of
* the initial process setup stack frames.
*/
public static class MethodAndArgsCaller extends Exception
implements Runnable {
/** method to call */
private final Method mMethod;
/** argument array */
private final String[] mArgs;
public MethodAndArgsCaller(Method method, String[] args) {
mMethod = method;
mArgs = args;
}
public void run() {
try {
mMethod.invoke(null, new Object[] { mArgs });
} catch (IllegalAccessException ex) {
throw new RuntimeException(ex);
} catch (InvocationTargetException ex) {
Throwable cause = ex.getCause();
if (cause instanceof RuntimeException) {
throw (RuntimeException) cause;
} else if (cause instanceof Error) {
throw (Error) cause;
}
throw new RuntimeException(ex);
}
}
}
}