Rewrite selectReadable JNI in Java. (894724be) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/os/ZygoteInit.java

+26 −31

Original line number	Diff line number	Diff line
		@@ -16,6 +16,8 @@

		package com.android.internal.os;

		import static android.system.OsConstants.POLLIN;
		import static android.system.OsConstants.POLLOUT;
		import static android.system.OsConstants.S_IRWXG;
		import static android.system.OsConstants.S_IRWXO;

		@@ -32,6 +34,7 @@ import android.os.Trace;
		import android.system.ErrnoException;
		import android.system.Os;
		import android.system.OsConstants;
		import android.system.StructPollfd;
		import android.util.EventLog;
		import android.util.Log;
		import android.util.Slog;
		@@ -699,34 +702,36 @@ public class ZygoteInit {
		private static void runSelectLoop(String abiList) throws MethodAndArgsCaller {
		ArrayList<FileDescriptor> fds = new ArrayList<FileDescriptor>();
		ArrayList<ZygoteConnection> peers = new ArrayList<ZygoteConnection>();
		FileDescriptor[] fdArray = new FileDescriptor[4];

		fds.add(sServerSocket.getFileDescriptor());
		peers.add(null);

		while (true) {
		int index;

		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 {
		fdArray = fds.toArray(fdArray);
		index = selectReadable(fdArray);
		} catch (IOException ex) {
		throw new RuntimeException("Error in select()", ex);
		Os.poll(pollFds, -1);
		} catch (ErrnoException ex) {
		throw new RuntimeException("poll failed", ex);
		}

		if (index < 0) {
		throw new RuntimeException("Error in select()");
		} else if (index == 0) {
		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;
		done = peers.get(index).runOnce();

		boolean done = peers.get(i).runOnce();
		if (done) {
		peers.remove(index);
		fds.remove(index);
		peers.remove(i);
		fds.remove(i);
		}
		}
		}
		}
		@@ -766,16 +771,6 @@ public class ZygoteInit {
		*/
		static native int getpgid(int pid) throws IOException;

		/**
		* Invokes select() on the provider array of file descriptors (selecting
		* for readability only). Array elements of null are ignored.
		*
		* @param fds non-null; array of readable file descriptors
		* @return index of descriptor that is now readable or -1 for empty array.
		* @throws IOException if an error occurs
		*/
		static native int selectReadable(FileDescriptor[] fds) throws IOException;

		/**
		* Class not instantiable.
		*/

core/jni/com_android_internal_os_ZygoteInit.cpp

+0 −69

Original line number	Diff line number	Diff line
		@@ -88,73 +88,6 @@ static jint com_android_internal_os_ZygoteInit_getpgid(
		return ret;
		}

		static jint com_android_internal_os_ZygoteInit_selectReadable (
		JNIEnv *env, jobject clazz, jobjectArray fds)
		{
		if (fds == NULL) {
		jniThrowNullPointerException(env, "fds == null");
		return -1;
		}

		jsize length = env->GetArrayLength(fds);
		fd_set fdset;

		if (env->ExceptionCheck()) {
		return -1;
		}

		FD_ZERO(&fdset);

		int nfds = 0;
		for (jsize i = 0; i < length; i++) {
		jobject fdObj = env->GetObjectArrayElement(fds, i);
		if (env->ExceptionCheck()) {
		return -1;
		}
		if (fdObj == NULL) {
		continue;
		}
		int fd = jniGetFDFromFileDescriptor(env, fdObj);
		if (env->ExceptionCheck()) {
		return -1;
		}

		FD_SET(fd, &fdset);

		if (fd >= nfds) {
		nfds = fd + 1;
		}
		}

		int err;
		do {
		err = select (nfds, &fdset, NULL, NULL, NULL);
		} while (err < 0 && errno == EINTR);

		if (err < 0) {
		jniThrowIOException(env, errno);
		return -1;
		}

		for (jsize i = 0; i < length; i++) {
		jobject fdObj = env->GetObjectArrayElement(fds, i);
		if (env->ExceptionCheck()) {
		return -1;
		}
		if (fdObj == NULL) {
		continue;
		}
		int fd = jniGetFDFromFileDescriptor(env, fdObj);
		if (env->ExceptionCheck()) {
		return -1;
		}
		if (FD_ISSET(fd, &fdset)) {
		return (jint)i;
		}
		}
		return -1;
		}

		/*
		* JNI registration.
		*/
		@@ -168,8 +101,6 @@ static JNINativeMethod gMethods[] = {
		(void *) com_android_internal_os_ZygoteInit_setpgid },
		{ "getpgid", "(I)I",
		(void *) com_android_internal_os_ZygoteInit_getpgid },
		{ "selectReadable", "([Ljava/io/FileDescriptor;)I",
		(void *) com_android_internal_os_ZygoteInit_selectReadable },
		};
		int register_com_android_internal_os_ZygoteInit(JNIEnv* env)
		{