/**
* Handles post-fork setup of child proc, closing sockets as appropriate, reopen stdio as
* appropriate, and ultimately throwing MethodAndArgsCaller if successful or returning if failed.
*
* @param parsedArgs non-null; zygote args
* @param descriptors null-ok; new file descriptors for stdio if available.
* @param pipeFd null-ok; pipe for communication back to Zygote.
* @param newStderr null-ok; stream to use for stderr until stdio is reopened.
* @throws ZygoteInit.MethodAndArgsCaller on success to trampoline to code that invokes static
* main.
*/
private void handleChildProc(
Arguments parsedArgs,
FileDescriptor[] descriptors,
FileDescriptor pipeFd,
PrintStream newStderr)
throws ZygoteInit.MethodAndArgsCaller {
/*
* Close the socket, unless we're in "peer wait" mode, in which
* case it's used to track the liveness of this process.
*/
if (parsedArgs.peerWait) {
try {
ZygoteInit.setCloseOnExec(mSocket.getFileDescriptor(), true);
sPeerWaitSocket = mSocket;
} catch (IOException ex) {
Log.e(TAG, "Zygote Child: error setting peer wait " + "socket to be close-on-exec", ex);
}
} else {
closeSocket();
ZygoteInit.closeServerSocket();
}
if (descriptors != null) {
try {
ZygoteInit.reopenStdio(descriptors[0], descriptors[1], descriptors[2]);
for (FileDescriptor fd : descriptors) {
IoUtils.closeQuietly(fd);
}
newStderr = System.err;
} catch (IOException ex) {
Log.e(TAG, "Error reopening stdio", ex);
}
}
if (parsedArgs.niceName != null) {
Process.setArgV0(parsedArgs.niceName);
}
if (parsedArgs.runtimeInit) {
if (parsedArgs.invokeWith != null) {
WrapperInit.execApplication(
parsedArgs.invokeWith,
parsedArgs.niceName,
parsedArgs.targetSdkVersion,
pipeFd,
parsedArgs.remainingArgs);
} else {
RuntimeInit.zygoteInit(parsedArgs.targetSdkVersion, parsedArgs.remainingArgs);
}
} else {
String className;
try {
className = parsedArgs.remainingArgs[0];
} catch (ArrayIndexOutOfBoundsException ex) {
logAndPrintError(newStderr, "Missing required class name argument", null);
return;
}
String[] mainArgs = new String[parsedArgs.remainingArgs.length - 1];
System.arraycopy(parsedArgs.remainingArgs, 1, mainArgs, 0, mainArgs.length);
if (parsedArgs.invokeWith != null) {
WrapperInit.execStandalone(
parsedArgs.invokeWith, parsedArgs.classpath, className, mainArgs);
} else {
ClassLoader cloader;
if (parsedArgs.classpath != null) {
cloader = new PathClassLoader(parsedArgs.classpath, ClassLoader.getSystemClassLoader());
} else {
cloader = ClassLoader.getSystemClassLoader();
}
try {
ZygoteInit.invokeStaticMain(cloader, className, mainArgs);
} catch (RuntimeException ex) {
logAndPrintError(newStderr, "Error starting.", ex);
}
}
}
}
/**
* Reads one start command from the command socket. If successful, a child is forked and a {@link
* ZygoteInit.MethodAndArgsCaller} exception is thrown in that child while in the parent process,
* the method returns normally. On failure, the child is not spawned and messages are printed to
* the log and stderr. Returns a boolean status value indicating whether an end-of-file on the
* command socket has been encountered.
*
* @return false if command socket should continue to be read from, or true if an end-of-file has
* been encountered.
* @throws ZygoteInit.MethodAndArgsCaller trampoline to invoke main() method in child process
*/
boolean runOnce() throws ZygoteInit.MethodAndArgsCaller {
String args[];
Arguments parsedArgs = null;
FileDescriptor[] descriptors;
try {
args = readArgumentList();
descriptors = mSocket.getAncillaryFileDescriptors();
} catch (IOException ex) {
Log.w(TAG, "IOException on command socket " + ex.getMessage());
closeSocket();
return true;
}
if (args == null) {
// EOF reached.
closeSocket();
return true;
}
/** the stderr of the most recent request, if avail */
PrintStream newStderr = null;
if (descriptors != null && descriptors.length >= 3) {
newStderr = new PrintStream(new FileOutputStream(descriptors[2]));
}
int pid = -1;
FileDescriptor childPipeFd = null;
FileDescriptor serverPipeFd = null;
try {
parsedArgs = new Arguments(args);
applyUidSecurityPolicy(parsedArgs, peer);
applyRlimitSecurityPolicy(parsedArgs, peer);
applyCapabilitiesSecurityPolicy(parsedArgs, peer);
applyInvokeWithSecurityPolicy(parsedArgs, peer);
applyDebuggerSystemProperty(parsedArgs);
applyInvokeWithSystemProperty(parsedArgs);
int[][] rlimits = null;
if (parsedArgs.rlimits != null) {
rlimits = parsedArgs.rlimits.toArray(intArray2d);
}
if (parsedArgs.runtimeInit && parsedArgs.invokeWith != null) {
FileDescriptor[] pipeFds = Libcore.os.pipe();
childPipeFd = pipeFds[1];
serverPipeFd = pipeFds[0];
ZygoteInit.setCloseOnExec(serverPipeFd, true);
}
pid =
Zygote.forkAndSpecialize(
parsedArgs.uid, parsedArgs.gid, parsedArgs.gids, parsedArgs.debugFlags, rlimits);
} catch (IOException ex) {
logAndPrintError(newStderr, "Exception creating pipe", ex);
} catch (ErrnoException ex) {
logAndPrintError(newStderr, "Exception creating pipe", ex);
} catch (IllegalArgumentException ex) {
logAndPrintError(newStderr, "Invalid zygote arguments", ex);
} catch (ZygoteSecurityException ex) {
logAndPrintError(newStderr, "Zygote security policy prevents request: ", ex);
}
try {
if (pid == 0) {
// in child
IoUtils.closeQuietly(serverPipeFd);
serverPipeFd = null;
handleChildProc(parsedArgs, descriptors, childPipeFd, newStderr);
// should never get here, the child is expected to either
// throw ZygoteInit.MethodAndArgsCaller or exec().
return true;
} else {
// in parent...pid of < 0 means failure
IoUtils.closeQuietly(childPipeFd);
childPipeFd = null;
return handleParentProc(pid, descriptors, serverPipeFd, parsedArgs);
}
} finally {
IoUtils.closeQuietly(childPipeFd);
IoUtils.closeQuietly(serverPipeFd);
}
}