jdk/src/solaris/classes/sun/nio/ch/DevPollArrayWrapper.java - platform/libcore - Git at Google

 /*
  * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Sun designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Sun in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  */

 package sun.nio.ch;

 import sun.misc.*;
 import java.io.IOException;
 import java.util.LinkedList;


 /**
  * Manipulates a native array of pollfd structs on Solaris:
  *
  * typedef struct pollfd {
  *    int fd;
  *    short events;
  *    short revents;
  * } pollfd_t;
  *
  * @author Mike McCloskey
  * @since 1.4
  */

 class DevPollArrayWrapper {

     // Event masks
     static final short POLLIN       = 0x0001;
     static final short POLLPRI      = 0x0002;
     static final short POLLOUT      = 0x0004;
     static final short POLLRDNORM   = 0x0040;
     static final short POLLWRNORM   = POLLOUT;
     static final short POLLRDBAND   = 0x0080;
     static final short POLLWRBAND   = 0x0100;
     static final short POLLNORM     = POLLRDNORM;
     static final short POLLERR      = 0x0008;
     static final short POLLHUP      = 0x0010;
     static final short POLLNVAL     = 0x0020;
     static final short POLLREMOVE   = 0x0800;
     static final short POLLCONN     = POLLOUT;

     // Miscellaneous constants
     static final short SIZE_POLLFD   = 8;
     static final short FD_OFFSET     = 0;
     static final short EVENT_OFFSET  = 4;
     static final short REVENT_OFFSET = 6;

     // Maximum number of open file descriptors
     static final int   OPEN_MAX      = fdLimit();

     // Number of pollfd structures to create.
     // DP_POLL ioctl allows up to OPEN_MAX-1
     static final int   NUM_POLLFDS   = Math.min(OPEN_MAX-1, 8192);

     // Base address of the native pollArray
     private long pollArrayAddress;

     // Maximum number of POLL_FD structs to update at once
     private int MAX_UPDATE_SIZE = 10000;

     DevPollArrayWrapper() {
         int allocationSize = NUM_POLLFDS * SIZE_POLLFD;
         pollArray = new AllocatedNativeObject(allocationSize, true);
         pollArrayAddress = pollArray.address();
         wfd = init();

         for (int i=0; i<NUM_POLLFDS; i++) {
             putDescriptor(i, 0);
             putEventOps(i, 0);
             putReventOps(i, 0);
         }
     }

     // Machinery for remembering fd registration changes
     // A hashmap could be used but the number of changes pending
     // is expected to be small
     private static class Updator {
         int fd;
         int mask;
         Updator(int fd, int mask) {
             this.fd = fd;
             this.mask = mask;
         }
     }
     private LinkedList<Updator> updateList = new LinkedList<Updator>();

     // The pollfd array for results from devpoll driver
     private AllocatedNativeObject pollArray;

     // The fd of the devpoll driver
     int wfd;

     // The fd of the interrupt line going out
     int outgoingInterruptFD;

     // The fd of the interrupt line coming in
     int incomingInterruptFD;

     // The index of the interrupt FD
     int interruptedIndex;

     // Number of updated pollfd entries
     int updated;

     void initInterrupt(int fd0, int fd1) {
         outgoingInterruptFD = fd1;
         incomingInterruptFD = fd0;
         register(wfd, fd0, POLLIN);
     }

     void putEventOps(int i, int event) {
         int offset = SIZE_POLLFD * i + EVENT_OFFSET;
         pollArray.putShort(offset, (short)event);
     }

     void putReventOps(int i, int revent) {
         int offset = SIZE_POLLFD * i + REVENT_OFFSET;
         pollArray.putShort(offset, (short)revent);
     }

     void putDescriptor(int i, int fd) {
         int offset = SIZE_POLLFD * i + FD_OFFSET;
         pollArray.putInt(offset, fd);
     }

     int getEventOps(int i) {
         int offset = SIZE_POLLFD * i + EVENT_OFFSET;
         return pollArray.getShort(offset);
     }

     int getReventOps(int i) {
         int offset = SIZE_POLLFD * i + REVENT_OFFSET;
         return pollArray.getShort(offset);
     }

     int getDescriptor(int i) {
         int offset = SIZE_POLLFD * i + FD_OFFSET;
         return pollArray.getInt(offset);
     }

     void setInterest(int fd, int mask) {
         synchronized (updateList) {
             updateList.add(new Updator(fd, mask));
         }
     }

     void release(int fd) {
         synchronized (updateList) {
             updateList.add(new Updator(fd, POLLREMOVE));
         }
     }

     void closeDevPollFD() throws IOException {
         FileDispatcherImpl.closeIntFD(wfd);
         pollArray.free();
     }

     int poll(long timeout) {
         updateRegistrations();
         updated = poll0(pollArrayAddress, NUM_POLLFDS, timeout, wfd);
         for (int i=0; i<updated; i++) {
             if (getDescriptor(i) == incomingInterruptFD) {
                 interruptedIndex = i;
                 interrupted = true;
                 break;
             }
         }
         return updated;
     }

     void updateRegistrations() {
         // take snapshot of the updateList size to see if there are
         // any registrations to update
         int updateSize;
         synchronized (updateList) {
             updateSize = updateList.size();
         }
         if (updateSize > 0) {
             // Construct a pollfd array with updated masks; we may overallocate
             // by some amount because if the events are already POLLREMOVE
             // then the second pollfd of that pair will not be needed. The
             // number of entries is limited to a reasonable number to avoid
             // allocating a lot of memory.
             int maxUpdates = Math.min(updateSize * 2, MAX_UPDATE_SIZE);
             int allocationSize =  maxUpdates * SIZE_POLLFD;
             AllocatedNativeObject updatePollArray =
                 new AllocatedNativeObject(allocationSize, true);

             try {
                 synchronized (updateList) {
                     while (updateList.size() > 0) {
                         // We have to insert a dummy node in between each
                         // real update to use POLLREMOVE on the fd first because
                         // otherwise the changes are simply OR'd together
                         int index = 0;
                         Updator u = null;
                         while ((u = updateList.poll()) != null) {
                             // First add pollfd struct to clear out this fd
                             putPollFD(updatePollArray, index, u.fd, POLLREMOVE);
                             index++;
                             // Now add pollfd to update this fd, if necessary
                             if (u.mask != POLLREMOVE) {
                                 putPollFD(updatePollArray, index, u.fd,
                                           (short)u.mask);
                                 index++;
                             }

                             // Check against the max allocation size; these are
                             // all we will process. Valid index ranges from 0 to
                             // (maxUpdates - 1) and we can use up to 2 per loop
                             if (index > maxUpdates - 2)
                                 break;
                         }
                         // Register the changes with /dev/poll
                         registerMultiple(wfd, updatePollArray.address(), index);
                      }
                 }
             } finally {
                 // Free the native array
                 updatePollArray.free();
                 // BUG: If an exception was thrown then the selector now believes
                 // that the last set of changes was updated but it probably
                 // was not. This should not be a likely occurrence.
             }
         }
     }

     private void putPollFD(AllocatedNativeObject array, int index, int fd,
                            short event)
     {
         int structIndex = SIZE_POLLFD * index;
         array.putInt(structIndex + FD_OFFSET, fd);
         array.putShort(structIndex + EVENT_OFFSET, event);
         array.putShort(structIndex + REVENT_OFFSET, (short)0);
     }

     boolean interrupted = false;

     public void interrupt() {
         interrupt(outgoingInterruptFD);
     }

     public int interruptedIndex() {
         return interruptedIndex;
     }

     boolean interrupted() {
         return interrupted;
     }

     void clearInterrupted() {
         interrupted = false;
     }

     private native int init();
     private native void register(int wfd, int fd, int mask);
     private native void registerMultiple(int wfd, long address, int len);
     private native int poll0(long pollAddress, int numfds, long timeout,
                              int wfd);
     private static native void interrupt(int fd);
     private static native int fdLimit();

 }
	/*
	* Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Sun designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Sun in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
	* CA 95054 USA or visit www.sun.com if you need additional information or
	* have any questions.
	*/

	package sun.nio.ch;

	import sun.misc.*;
	import java.io.IOException;
	import java.util.LinkedList;


	/**
	* Manipulates a native array of pollfd structs on Solaris:
	*
	* typedef struct pollfd {
	* int fd;
	* short events;
	* short revents;
	* } pollfd_t;
	*
	* @author Mike McCloskey
	* @since 1.4
	*/

	class DevPollArrayWrapper {

	// Event masks
	static final short POLLIN = 0x0001;
	static final short POLLPRI = 0x0002;
	static final short POLLOUT = 0x0004;
	static final short POLLRDNORM = 0x0040;
	static final short POLLWRNORM = POLLOUT;
	static final short POLLRDBAND = 0x0080;
	static final short POLLWRBAND = 0x0100;
	static final short POLLNORM = POLLRDNORM;
	static final short POLLERR = 0x0008;
	static final short POLLHUP = 0x0010;
	static final short POLLNVAL = 0x0020;
	static final short POLLREMOVE = 0x0800;
	static final short POLLCONN = POLLOUT;

	// Miscellaneous constants
	static final short SIZE_POLLFD = 8;
	static final short FD_OFFSET = 0;
	static final short EVENT_OFFSET = 4;
	static final short REVENT_OFFSET = 6;

	// Maximum number of open file descriptors
	static final int OPEN_MAX = fdLimit();

	// Number of pollfd structures to create.
	// DP_POLL ioctl allows up to OPEN_MAX-1
	static final int NUM_POLLFDS = Math.min(OPEN_MAX-1, 8192);

	// Base address of the native pollArray
	private long pollArrayAddress;

	// Maximum number of POLL_FD structs to update at once
	private int MAX_UPDATE_SIZE = 10000;

	DevPollArrayWrapper() {
	int allocationSize = NUM_POLLFDS * SIZE_POLLFD;
	pollArray = new AllocatedNativeObject(allocationSize, true);
	pollArrayAddress = pollArray.address();
	wfd = init();

	for (int i=0; i<NUM_POLLFDS; i++) {
	putDescriptor(i, 0);
	putEventOps(i, 0);
	putReventOps(i, 0);
	}
	}

	// Machinery for remembering fd registration changes
	// A hashmap could be used but the number of changes pending
	// is expected to be small
	private static class Updator {
	int fd;
	int mask;
	Updator(int fd, int mask) {
	this.fd = fd;
	this.mask = mask;
	}
	}
	private LinkedList<Updator> updateList = new LinkedList<Updator>();

	// The pollfd array for results from devpoll driver
	private AllocatedNativeObject pollArray;

	// The fd of the devpoll driver
	int wfd;

	// The fd of the interrupt line going out
	int outgoingInterruptFD;

	// The fd of the interrupt line coming in
	int incomingInterruptFD;

	// The index of the interrupt FD
	int interruptedIndex;

	// Number of updated pollfd entries
	int updated;

	void initInterrupt(int fd0, int fd1) {
	outgoingInterruptFD = fd1;
	incomingInterruptFD = fd0;
	register(wfd, fd0, POLLIN);
	}

	void putEventOps(int i, int event) {
	int offset = SIZE_POLLFD * i + EVENT_OFFSET;
	pollArray.putShort(offset, (short)event);
	}

	void putReventOps(int i, int revent) {
	int offset = SIZE_POLLFD * i + REVENT_OFFSET;
	pollArray.putShort(offset, (short)revent);
	}

	void putDescriptor(int i, int fd) {
	int offset = SIZE_POLLFD * i + FD_OFFSET;
	pollArray.putInt(offset, fd);
	}

	int getEventOps(int i) {
	int offset = SIZE_POLLFD * i + EVENT_OFFSET;
	return pollArray.getShort(offset);
	}

	int getReventOps(int i) {
	int offset = SIZE_POLLFD * i + REVENT_OFFSET;
	return pollArray.getShort(offset);
	}

	int getDescriptor(int i) {
	int offset = SIZE_POLLFD * i + FD_OFFSET;
	return pollArray.getInt(offset);
	}

	void setInterest(int fd, int mask) {
	synchronized (updateList) {
	updateList.add(new Updator(fd, mask));
	}
	}

	void release(int fd) {
	synchronized (updateList) {
	updateList.add(new Updator(fd, POLLREMOVE));
	}
	}

	void closeDevPollFD() throws IOException {
	FileDispatcherImpl.closeIntFD(wfd);
	pollArray.free();
	}

	int poll(long timeout) {
	updateRegistrations();
	updated = poll0(pollArrayAddress, NUM_POLLFDS, timeout, wfd);
	for (int i=0; i<updated; i++) {
	if (getDescriptor(i) == incomingInterruptFD) {
	interruptedIndex = i;
	interrupted = true;
	break;
	}
	}
	return updated;
	}

	void updateRegistrations() {
	// take snapshot of the updateList size to see if there are
	// any registrations to update
	int updateSize;
	synchronized (updateList) {
	updateSize = updateList.size();
	}
	if (updateSize > 0) {
	// Construct a pollfd array with updated masks; we may overallocate
	// by some amount because if the events are already POLLREMOVE
	// then the second pollfd of that pair will not be needed. The
	// number of entries is limited to a reasonable number to avoid
	// allocating a lot of memory.
	int maxUpdates = Math.min(updateSize * 2, MAX_UPDATE_SIZE);
	int allocationSize = maxUpdates * SIZE_POLLFD;
	AllocatedNativeObject updatePollArray =
	new AllocatedNativeObject(allocationSize, true);

	try {
	synchronized (updateList) {
	while (updateList.size() > 0) {
	// We have to insert a dummy node in between each
	// real update to use POLLREMOVE on the fd first because
	// otherwise the changes are simply OR'd together
	int index = 0;
	Updator u = null;
	while ((u = updateList.poll()) != null) {
	// First add pollfd struct to clear out this fd
	putPollFD(updatePollArray, index, u.fd, POLLREMOVE);
	index++;
	// Now add pollfd to update this fd, if necessary
	if (u.mask != POLLREMOVE) {
	putPollFD(updatePollArray, index, u.fd,
	(short)u.mask);
	index++;
	}

	// Check against the max allocation size; these are
	// all we will process. Valid index ranges from 0 to
	// (maxUpdates - 1) and we can use up to 2 per loop
	if (index > maxUpdates - 2)
	break;
	}
	// Register the changes with /dev/poll
	registerMultiple(wfd, updatePollArray.address(), index);
	}
	}
	} finally {
	// Free the native array
	updatePollArray.free();
	// BUG: If an exception was thrown then the selector now believes
	// that the last set of changes was updated but it probably
	// was not. This should not be a likely occurrence.
	}
	}
	}

	private void putPollFD(AllocatedNativeObject array, int index, int fd,
	short event)
	{
	int structIndex = SIZE_POLLFD * index;
	array.putInt(structIndex + FD_OFFSET, fd);
	array.putShort(structIndex + EVENT_OFFSET, event);
	array.putShort(structIndex + REVENT_OFFSET, (short)0);
	}

	boolean interrupted = false;

	public void interrupt() {
	interrupt(outgoingInterruptFD);
	}

	public int interruptedIndex() {
	return interruptedIndex;
	}

	boolean interrupted() {
	return interrupted;
	}

	void clearInterrupted() {
	interrupted = false;
	}

	private native int init();
	private native void register(int wfd, int fd, int mask);
	private native void registerMultiple(int wfd, long address, int len);
	private native int poll0(long pollAddress, int numfds, long timeout,
	int wfd);
	private static native void interrupt(int fd);
	private static native int fdLimit();

	}