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package sun.nio.ch;

import java.io.FileDescriptor;
import java.io.IOException;
import java.net.*;
import java.nio.channels.*;
import java.nio.channels.spi.*;
import java.util.*;
import sun.net.NetHooks;

An implementation of ServerSocketChannels
/** * An implementation of ServerSocketChannels */
class ServerSocketChannelImpl extends ServerSocketChannel implements SelChImpl { // Used to make native close and configure calls private static NativeDispatcher nd; // Our file descriptor private final FileDescriptor fd; // fd value needed for dev/poll. This value will remain valid // even after the value in the file descriptor object has been set to -1 private int fdVal; // ID of native thread currently blocked in this channel, for signalling private volatile long thread; // Lock held by thread currently blocked in this channel private final Object lock = new Object(); // Lock held by any thread that modifies the state fields declared below // DO NOT invoke a blocking I/O operation while holding this lock! private final Object stateLock = new Object(); // -- The following fields are protected by stateLock // Channel state, increases monotonically private static final int ST_UNINITIALIZED = -1; private static final int ST_INUSE = 0; private static final int ST_KILLED = 1; private int state = ST_UNINITIALIZED; // Binding private InetSocketAddress localAddress; // null => unbound // set true when exclusive binding is on and SO_REUSEADDR is emulated private boolean isReuseAddress; // Our socket adaptor, if any ServerSocket socket; // -- End of fields protected by stateLock ServerSocketChannelImpl(SelectorProvider sp) throws IOException { super(sp); this.fd = Net.serverSocket(true); this.fdVal = IOUtil.fdVal(fd); this.state = ST_INUSE; } ServerSocketChannelImpl(SelectorProvider sp, FileDescriptor fd, boolean bound) throws IOException { super(sp); this.fd = fd; this.fdVal = IOUtil.fdVal(fd); this.state = ST_INUSE; if (bound) localAddress = Net.localAddress(fd); } public ServerSocket socket() { synchronized (stateLock) { if (socket == null) socket = ServerSocketAdaptor.create(this); return socket; } } @Override public SocketAddress getLocalAddress() throws IOException { synchronized (stateLock) { if (!isOpen()) throw new ClosedChannelException(); return localAddress == null ? localAddress : Net.getRevealedLocalAddress( Net.asInetSocketAddress(localAddress)); } } @Override public <T> ServerSocketChannel setOption(SocketOption<T> name, T value) throws IOException { if (name == null) throw new NullPointerException(); if (!supportedOptions().contains(name)) throw new UnsupportedOperationException("'" + name + "' not supported"); synchronized (stateLock) { if (!isOpen()) throw new ClosedChannelException(); if (name == StandardSocketOptions.IP_TOS) { ProtocolFamily family = Net.isIPv6Available() ? StandardProtocolFamily.INET6 : StandardProtocolFamily.INET; Net.setSocketOption(fd, family, name, value); return this; } if (name == StandardSocketOptions.SO_REUSEADDR && Net.useExclusiveBind()) { // SO_REUSEADDR emulated when using exclusive bind isReuseAddress = (Boolean)value; } else { // no options that require special handling Net.setSocketOption(fd, Net.UNSPEC, name, value); } return this; } } @Override @SuppressWarnings("unchecked") public <T> T getOption(SocketOption<T> name) throws IOException { if (name == null) throw new NullPointerException(); if (!supportedOptions().contains(name)) throw new UnsupportedOperationException("'" + name + "' not supported"); synchronized (stateLock) { if (!isOpen()) throw new ClosedChannelException(); if (name == StandardSocketOptions.SO_REUSEADDR && Net.useExclusiveBind()) { // SO_REUSEADDR emulated when using exclusive bind return (T)Boolean.valueOf(isReuseAddress); } // no options that require special handling return (T) Net.getSocketOption(fd, Net.UNSPEC, name); } } private static class DefaultOptionsHolder { static final Set<SocketOption<?>> defaultOptions = defaultOptions(); private static Set<SocketOption<?>> defaultOptions() { HashSet<SocketOption<?>> set = new HashSet<>(2); set.add(StandardSocketOptions.SO_RCVBUF); set.add(StandardSocketOptions.SO_REUSEADDR); if (Net.isReusePortAvailable()) { set.add(StandardSocketOptions.SO_REUSEPORT); } set.add(StandardSocketOptions.IP_TOS); return Collections.unmodifiableSet(set); } } @Override public final Set<SocketOption<?>> supportedOptions() { return DefaultOptionsHolder.defaultOptions; } public boolean isBound() { synchronized (stateLock) { return localAddress != null; } } public InetSocketAddress localAddress() { synchronized (stateLock) { return localAddress; } } @Override public ServerSocketChannel bind(SocketAddress local, int backlog) throws IOException { synchronized (lock) { if (!isOpen()) throw new ClosedChannelException(); if (isBound()) throw new AlreadyBoundException(); InetSocketAddress isa = (local == null) ? new InetSocketAddress(0) : Net.checkAddress(local); SecurityManager sm = System.getSecurityManager(); if (sm != null) sm.checkListen(isa.getPort()); NetHooks.beforeTcpBind(fd, isa.getAddress(), isa.getPort()); Net.bind(fd, isa.getAddress(), isa.getPort()); Net.listen(fd, backlog < 1 ? 50 : backlog); synchronized (stateLock) { localAddress = Net.localAddress(fd); } } return this; } public SocketChannel accept() throws IOException { synchronized (lock) { if (!isOpen()) throw new ClosedChannelException(); if (!isBound()) throw new NotYetBoundException(); SocketChannel sc = null; int n = 0; FileDescriptor newfd = new FileDescriptor(); InetSocketAddress[] isaa = new InetSocketAddress[1]; try { begin(); if (!isOpen()) return null; thread = NativeThread.current(); for (;;) { n = accept(this.fd, newfd, isaa); if ((n == IOStatus.INTERRUPTED) && isOpen()) continue; break; } } finally { thread = 0; end(n > 0); assert IOStatus.check(n); } if (n < 1) return null; IOUtil.configureBlocking(newfd, true); InetSocketAddress isa = isaa[0]; sc = new SocketChannelImpl(provider(), newfd, isa); SecurityManager sm = System.getSecurityManager(); if (sm != null) { try { sm.checkAccept(isa.getAddress().getHostAddress(), isa.getPort()); } catch (SecurityException x) { sc.close(); throw x; } } return sc; } } protected void implConfigureBlocking(boolean block) throws IOException { IOUtil.configureBlocking(fd, block); } protected void implCloseSelectableChannel() throws IOException { synchronized (stateLock) { if (state != ST_KILLED) nd.preClose(fd); long th = thread; if (th != 0) NativeThread.signal(th); if (!isRegistered()) kill(); } } public void kill() throws IOException { synchronized (stateLock) { if (state == ST_KILLED) return; if (state == ST_UNINITIALIZED) { state = ST_KILLED; return; } assert !isOpen() && !isRegistered(); nd.close(fd); state = ST_KILLED; } }
Translates native poll revent set into a ready operation set
/** * Translates native poll revent set into a ready operation set */
public boolean translateReadyOps(int ops, int initialOps, SelectionKeyImpl sk) { int intOps = sk.nioInterestOps(); // Do this just once, it synchronizes int oldOps = sk.nioReadyOps(); int newOps = initialOps; if ((ops & Net.POLLNVAL) != 0) { // This should only happen if this channel is pre-closed while a // selection operation is in progress // ## Throw an error if this channel has not been pre-closed return false; } if ((ops & (Net.POLLERR | Net.POLLHUP)) != 0) { newOps = intOps; sk.nioReadyOps(newOps); return (newOps & ~oldOps) != 0; } if (((ops & Net.POLLIN) != 0) && ((intOps & SelectionKey.OP_ACCEPT) != 0)) newOps |= SelectionKey.OP_ACCEPT; sk.nioReadyOps(newOps); return (newOps & ~oldOps) != 0; } public boolean translateAndUpdateReadyOps(int ops, SelectionKeyImpl sk) { return translateReadyOps(ops, sk.nioReadyOps(), sk); } public boolean translateAndSetReadyOps(int ops, SelectionKeyImpl sk) { return translateReadyOps(ops, 0, sk); } // package-private int poll(int events, long timeout) throws IOException { assert Thread.holdsLock(blockingLock()) && !isBlocking(); synchronized (lock) { int n = 0; try { begin(); synchronized (stateLock) { if (!isOpen()) return 0; thread = NativeThread.current(); } n = Net.poll(fd, events, timeout); } finally { thread = 0; end(n > 0); } return n; } }
Translates an interest operation set into a native poll event set
/** * Translates an interest operation set into a native poll event set */
public void translateAndSetInterestOps(int ops, SelectionKeyImpl sk) { int newOps = 0; // Translate ops if ((ops & SelectionKey.OP_ACCEPT) != 0) newOps |= Net.POLLIN; // Place ops into pollfd array sk.selector.putEventOps(sk, newOps); } public FileDescriptor getFD() { return fd; } public int getFDVal() { return fdVal; } public String toString() { StringBuilder sb = new StringBuilder(); sb.append(this.getClass().getName()); sb.append('['); if (!isOpen()) { sb.append("closed"); } else { synchronized (stateLock) { InetSocketAddress addr = localAddress(); if (addr == null) { sb.append("unbound"); } else { sb.append(Net.getRevealedLocalAddressAsString(addr)); } } } sb.append(']'); return sb.toString(); }
Accept a connection on a socket.
Implementation Note:Wrap native call to allow instrumentation.
/** * Accept a connection on a socket. * * @implNote Wrap native call to allow instrumentation. */
private int accept(FileDescriptor ssfd, FileDescriptor newfd, InetSocketAddress[] isaa) throws IOException { return accept0(ssfd, newfd, isaa); } // -- Native methods -- // Accepts a new connection, setting the given file descriptor to refer to // the new socket and setting isaa[0] to the socket's remote address. // Returns 1 on success, or IOStatus.UNAVAILABLE (if non-blocking and no // connections are pending) or IOStatus.INTERRUPTED. // private native int accept0(FileDescriptor ssfd, FileDescriptor newfd, InetSocketAddress[] isaa) throws IOException; private static native void initIDs(); static { IOUtil.load(); initIDs(); nd = new SocketDispatcher(); } }