Proper handling of epoll_ctl errors

Motivation:

When using epoll_ctl we should respect the return value and do the right thing depending on it.

Modifications:

Adjust java and native code to respect epoll_ctl return values.

Result:

Correct and cleaner code.
This commit is contained in:
Norman Maurer 2015-04-30 09:38:35 +02:00
parent 2ab9d659c7
commit b3abd58b05
6 changed files with 78 additions and 30 deletions

View File

@ -686,27 +686,30 @@ JNIEXPORT jint JNICALL Java_io_netty_channel_epoll_Native_epollWait0(JNIEnv* env
return ready;
}
JNIEXPORT void JNICALL Java_io_netty_channel_epoll_Native_epollCtlAdd(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags) {
if (epollCtl(env, efd, EPOLL_CTL_ADD, fd, flags) < 0) {
int err = errno;
throwRuntimeException(env, exceptionMessage("epoll_ctl() failed: ", err));
JNIEXPORT jint JNICALL Java_io_netty_channel_epoll_Native_epollCtlAdd0(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags) {
int res = epollCtl(env, efd, EPOLL_CTL_ADD, fd, flags);
if (res < 0) {
return -errno;
}
return res;
}
JNIEXPORT void JNICALL Java_io_netty_channel_epoll_Native_epollCtlMod(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags) {
if (epollCtl(env, efd, EPOLL_CTL_MOD, fd, flags) < 0) {
int err = errno;
throwRuntimeException(env, exceptionMessage("epoll_ctl() failed: ", err));
JNIEXPORT jint JNICALL Java_io_netty_channel_epoll_Native_epollCtlMod0(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags) {
int res = epollCtl(env, efd, EPOLL_CTL_MOD, fd, flags);
if (res < 0) {
return -errno;
}
return res;
}
JNIEXPORT void JNICALL Java_io_netty_channel_epoll_Native_epollCtlDel(JNIEnv* env, jclass clazz, jint efd, jint fd) {
JNIEXPORT jint JNICALL Java_io_netty_channel_epoll_Native_epollCtlDel0(JNIEnv* env, jclass clazz, jint efd, jint fd) {
// Create an empty event to workaround a bug in older kernels which can not handle NULL.
struct epoll_event event = { 0 };
if (epoll_ctl(efd, EPOLL_CTL_DEL, fd, &event) < 0) {
int err = errno;
throwRuntimeException(env, exceptionMessage("epoll_ctl() failed: ", err));
int res = epoll_ctl(efd, EPOLL_CTL_DEL, fd, &event);
if (res < 0) {
return -errno;
}
return res;
}
static inline jint _write(JNIEnv* env, jclass clazz, jint fd, void* buffer, jint pos, jint limit) {

View File

@ -38,9 +38,9 @@ void Java_io_netty_channel_epoll_Native_eventFdWrite(JNIEnv* env, jclass clazz,
void Java_io_netty_channel_epoll_Native_eventFdRead(JNIEnv* env, jclass clazz, jint fd);
jint Java_io_netty_channel_epoll_Native_epollCreate(JNIEnv* env, jclass clazz);
jint Java_io_netty_channel_epoll_Native_epollWait0(JNIEnv* env, jclass clazz, jint efd, jlong address, jint length, jint timeout);
void Java_io_netty_channel_epoll_Native_epollCtlAdd(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags);
void Java_io_netty_channel_epoll_Native_epollCtlMod(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags);
void Java_io_netty_channel_epoll_Native_epollCtlDel(JNIEnv* env, jclass clazz, jint efd, jint fd);
jint Java_io_netty_channel_epoll_Native_epollCtlAdd0(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags);
jint Java_io_netty_channel_epoll_Native_epollCtlMod0(JNIEnv* env, jclass clazz, jint efd, jint fd, jint flags);
jint Java_io_netty_channel_epoll_Native_epollCtlDel0(JNIEnv* env, jclass clazz, jint efd, jint fd);
jint Java_io_netty_channel_epoll_Native_write0(JNIEnv* env, jclass clazz, jint fd, jobject jbuffer, jint pos, jint limit);
jint Java_io_netty_channel_epoll_Native_writeAddress0(JNIEnv* env, jclass clazz, jint fd, jlong address, jint pos, jint limit);
jlong Java_io_netty_channel_epoll_Native_writev0(JNIEnv* env, jclass clazz, jint fd, jobjectArray buffers, jint offset, jint length);

View File

@ -28,6 +28,7 @@ import io.netty.channel.unix.UnixChannel;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.OneTimeTask;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.UnresolvedAddressException;
@ -59,14 +60,14 @@ abstract class AbstractEpollChannel extends AbstractChannel implements UnixChann
fileDescriptor = fd;
}
void setFlag(int flag) {
void setFlag(int flag) throws IOException {
if (!isFlagSet(flag)) {
flags |= flag;
modifyEvents();
}
}
void clearFlag(int flag) {
void clearFlag(int flag) throws IOException {
if (isFlagSet(flag)) {
flags &= ~flag;
modifyEvents();
@ -160,7 +161,7 @@ abstract class AbstractEpollChannel extends AbstractChannel implements UnixChann
}
}
private void modifyEvents() {
private void modifyEvents() throws IOException {
if (isOpen() && isRegistered()) {
((EpollEventLoop) eventLoop().unwrap()).modify(this);
}
@ -324,7 +325,15 @@ abstract class AbstractEpollChannel extends AbstractChannel implements UnixChann
}
protected final void clearEpollIn0() {
assert eventLoop().inEventLoop();
try {
clearFlag(readFlag);
} catch (IOException e) {
// When this happens there is something completely wrong with either the filedescriptor or epoll,
// so fire the exception through the pipeline and close the Channel.
pipeline().fireExceptionCaught(e);
unsafe().close(unsafe().voidPromise());
}
}
}
}

View File

@ -16,11 +16,13 @@
package io.netty.channel.epoll;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelOption;
import io.netty.channel.DefaultChannelConfig;
import io.netty.channel.MessageSizeEstimator;
import io.netty.channel.RecvByteBufAllocator;
import java.io.IOException;
import java.util.Map;
public class EpollChannelConfig extends DefaultChannelConfig {
@ -133,6 +135,7 @@ public class EpollChannelConfig extends DefaultChannelConfig {
if (mode == null) {
throw new NullPointerException("mode");
}
try {
switch (mode) {
case EDGE_TRIGGERED:
checkChannelNotRegistered();
@ -145,6 +148,9 @@ public class EpollChannelConfig extends DefaultChannelConfig {
default:
throw new Error();
}
} catch (IOException e) {
throw new ChannelException(e);
}
return this;
}

View File

@ -74,7 +74,11 @@ final class EpollEventLoop extends SingleThreadEventLoop {
try {
this.epollFd = epollFd = Native.epollCreate();
this.eventFd = eventFd = Native.eventFd();
try {
Native.epollCtlAdd(epollFd, eventFd, Native.EPOLLIN);
} catch (IOException e) {
throw new IllegalStateException("Unable to add eventFd filedescriptor to epoll", e);
}
success = true;
} finally {
if (!success) {
@ -107,7 +111,7 @@ final class EpollEventLoop extends SingleThreadEventLoop {
/**
* Register the given epoll with this {@link io.netty.channel.EventLoop}.
*/
void add(AbstractEpollChannel ch) {
void add(AbstractEpollChannel ch) throws IOException {
assert inEventLoop();
int fd = ch.fd().intValue();
Native.epollCtlAdd(epollFd, fd, ch.flags);
@ -117,15 +121,15 @@ final class EpollEventLoop extends SingleThreadEventLoop {
/**
* The flags of the given epoll was modified so update the registration
*/
void modify(AbstractEpollChannel ch) {
void modify(AbstractEpollChannel ch) throws IOException {
assert inEventLoop();
Native.epollCtlMod(epollFd, ch.fd().intValue(), ch.flags);
}
/**
* Deregister the given epoll from this {@link io.netty.channel.EventLoop}.
* Deregister the given epoll from this {@link EventLoop}.
*/
void remove(AbstractEpollChannel ch) {
void remove(AbstractEpollChannel ch) throws IOException {
assert inEventLoop();
if (ch.isOpen()) {
@ -328,7 +332,14 @@ final class EpollEventLoop extends SingleThreadEventLoop {
}
} else {
// We received an event for an fd which we not use anymore. Remove it from the epoll_event set.
try {
Native.epollCtlDel(epollFd, fd);
} catch (IOException ignore) {
// This can happen but is nothing we need to worry about as we only try to delete
// the fd from the epoll set as we not found it in our mappings. So this call to
// epollCtlDel(...) is just to ensure we cleanup stuff and so may fail if it was
// deleted before or the file descriptor was closed before.
}
}
}
}

View File

@ -156,10 +156,29 @@ public final class Native {
}
private static native int epollWait0(int efd, long address, int len, int timeout);
public static native void epollCtlAdd(int efd, final int fd, final int flags);
public static void epollCtlAdd(int efd, final int fd, final int flags) throws IOException {
int res = epollCtlAdd0(efd, fd, flags);
if (res < 0) {
throw newIOException("epoll_ctl", res);
}
}
private static native int epollCtlAdd0(int efd, final int fd, final int flags);
public static native void epollCtlMod(int efd, final int fd, final int flags);
public static native void epollCtlDel(int efd, final int fd);
public static void epollCtlMod(int efd, final int fd, final int flags) throws IOException {
int res = epollCtlMod0(efd, fd, flags);
if (res < 0) {
throw newIOException("epoll_ctl", res);
}
}
private static native int epollCtlMod0(int efd, final int fd, final int flags);
public static void epollCtlDel(int efd, final int fd) throws IOException {
int res = epollCtlDel0(efd, fd);
if (res < 0) {
throw newIOException("epoll_ctl", res);
}
}
private static native int epollCtlDel0(int efd, final int fd);
private static native int errnoEBADF();
private static native int errnoEPIPE();