Author: markt
Date: Thu May 21 15:31:43 2015
New Revision: 1680910
URL: http://svn.apache.org/r1680910
Log:
Re-thinking flow control / write coordination
WriteStateMachine no longer required (but it can be brought back from svn
history if I change my mind again).
Connection level flow control (trickier than stream level) is still TODO
Removed:
tomcat/trunk/java/org/apache/coyote/http2/WriteStateMachine.java
Modified:
tomcat/trunk/java/org/apache/coyote/http2/AbstractStream.java
tomcat/trunk/java/org/apache/coyote/http2/Http2UpgradeHandler.java
tomcat/trunk/java/org/apache/coyote/http2/Stream.java
Modified: tomcat/trunk/java/org/apache/coyote/http2/AbstractStream.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/coyote/http2/AbstractStream.java?rev=1680910&r1=1680909&r2=1680910&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/coyote/http2/AbstractStream.java (original)
+++ tomcat/trunk/java/org/apache/coyote/http2/AbstractStream.java Thu May 21
15:31:43 2015
@@ -35,6 +35,7 @@ abstract class AbstractStream {
private volatile AbstractStream parentStream = null;
private final Set<AbstractStream> childStreams = new HashSet<>();
private volatile int weight = Constants.DEFAULT_WEIGHT;
+ private volatile long windowSize = ConnectionSettings.DEFAULT_WINDOW_SIZE;
public Integer getIdentifier() {
return identifier;
@@ -120,6 +121,35 @@ abstract class AbstractStream {
return childStreams;
}
+
+ protected void setWindowSize(long windowSize) {
+ this.windowSize = windowSize;
+ }
+
+
+ protected long getWindowSize() {
+ return windowSize;
+ }
+
+
+ protected void incrementWindowSize(int increment) {
+ windowSize += increment;
+ }
+
+
+ protected void decrementWindowSize(int decrement) {
+ windowSize += decrement;
+ }
+
+ protected int reserveWindowSize(int reservation) {
+ if (reservation > windowSize) {
+ return (int) windowSize;
+ } else {
+ return reservation;
+ }
+ }
+
+
protected abstract Log getLog();
protected abstract int getConnectionId();
Modified: tomcat/trunk/java/org/apache/coyote/http2/Http2UpgradeHandler.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/coyote/http2/Http2UpgradeHandler.java?rev=1680910&r1=1680909&r2=1680910&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/coyote/http2/Http2UpgradeHandler.java
(original)
+++ tomcat/trunk/java/org/apache/coyote/http2/Http2UpgradeHandler.java Thu May
21 15:31:43 2015
@@ -32,7 +32,6 @@ import org.apache.coyote.Adapter;
import org.apache.coyote.Response;
import org.apache.coyote.http11.upgrade.InternalHttpUpgradeHandler;
import org.apache.coyote.http2.HpackEncoder.State;
-import org.apache.coyote.http2.WriteStateMachine.WriteState;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.http.MimeHeaders;
@@ -94,7 +93,6 @@ public class Http2UpgradeHandler extends
private final ConnectionSettings remoteSettings = new ConnectionSettings();
private final ConnectionSettings localSettings = new ConnectionSettings();
- private volatile long flowControlWindowSize =
ConnectionSettings.DEFAULT_WINDOW_SIZE;
private volatile int maxRemoteStreamId = 0;
private HpackDecoder hpackDecoder;
@@ -103,7 +101,6 @@ public class Http2UpgradeHandler extends
private final Map<Integer,Stream> streams = new HashMap<>();
- private final WriteStateMachine writeStateMachine = new
WriteStateMachine();
private final Queue<Object> writeQueue = new ConcurrentLinkedQueue<>();
public Http2UpgradeHandler(Adapter adapter) {
@@ -159,7 +156,6 @@ public class Http2UpgradeHandler extends
switch(status) {
case OPEN_READ:
- writeStateMachine.startRead();
// Gets set to null once the connection preface has been
// successfully parsed.
if (connectionPrefaceParser != null) {
@@ -181,13 +177,6 @@ public class Http2UpgradeHandler extends
try {
while (processFrame()) {
}
-
- // We are on a container thread. There is no more data to read
- // so check for writes (more efficient than dispatching to a
new
- // thread).
- if (writeStateMachine.endRead()) {
- processWrites();
- }
} catch (Http2Exception h2e) {
if (h2e.getStreamId() == 0) {
// Connection error
@@ -212,30 +201,28 @@ public class Http2UpgradeHandler extends
break;
case OPEN_WRITE:
- if (writeStateMachine.startWrite()) {
- try {
- processWrites();
- } catch (Http2Exception h2e) {
- if (h2e.getStreamId() == 0) {
- // Connection error
-
log.warn(sm.getString("upgradeHandler.connectionError"), h2e);
- close(h2e);
- break;
- } else {
- // Stream error
- // TODO Reset stream
- }
- } catch (IOException ioe) {
- if (log.isDebugEnabled()) {
- log.debug(sm.getString("upgradeHandler.ioerror",
- Long.toString(connectionId)), ioe);
- }
- close();
- result = SocketState.CLOSED;
+ try {
+ processWrites();
+ } catch (Http2Exception h2e) {
+ if (h2e.getStreamId() == 0) {
+ // Connection error
+ log.warn(sm.getString("upgradeHandler.connectionError"),
h2e);
+ close(h2e);
break;
+ } else {
+ // Stream error
+ // TODO Reset stream
}
-
+ } catch (IOException ioe) {
+ if (log.isDebugEnabled()) {
+ log.debug(sm.getString("upgradeHandler.ioerror",
+ Long.toString(connectionId)), ioe);
+ }
+ close();
+ result = SocketState.CLOSED;
+ break;
}
+
result = SocketState.UPGRADED;
break;
@@ -539,7 +526,7 @@ public class Http2UpgradeHandler extends
streamId, Http2Exception.PROTOCOL_ERROR);
}
if (streamId == 0) {
- flowControlWindowSize += windowSizeIncrement;
+ incrementWindowSize(windowSizeIncrement);
} else {
Stream stream = getStream(streamId);
if (stream == null) {
@@ -723,8 +710,7 @@ public class Http2UpgradeHandler extends
}
- void writeBody(Stream stream, ByteBuffer data) throws IOException {
- data.flip();
+ void writeBody(Stream stream, ByteBuffer data, int len) throws IOException
{
if (log.isDebugEnabled()) {
log.debug(sm.getString("upgradeHandler.writeBody",
Integer.toString(connectionId),
stream.getIdentifier(),
Integer.toString(data.remaining())));
@@ -732,14 +718,15 @@ public class Http2UpgradeHandler extends
synchronized (socketWrapper) {
// TODO Manage window sizes
byte[] header = new byte[9];
- ByteUtil.setThreeBytes(header, 0, data.remaining());
+ ByteUtil.setThreeBytes(header, 0, len);
header[3] = FRAME_TYPE_DATA;
if (stream.getOutputBuffer().isFinished()) {
header[4] = FLAG_END_OF_STREAM;
}
ByteUtil.set31Bits(header, 5, stream.getIdentifier().intValue());
socketWrapper.write(true, header, 0, header.length);
- socketWrapper.write(true, data.array(), data.arrayOffset(),
data.limit());
+ socketWrapper.write(true, data.array(), data.arrayOffset() +
data.position(),
+ len);
socketWrapper.flush(true);
}
}
@@ -760,31 +747,18 @@ public class Http2UpgradeHandler extends
private Object getThingToWrite() {
- synchronized (writeStateMachine) {
- // TODO This is more complicated than pulling an object off a
queue.
+ // TODO This is more complicated than pulling an object off a queue.
- // Note: The checking of the queue for something to write and the
- // calling of endWrite() if nothing is found must be kept
- // within the same sync to avoid race conditions with adding
- // entries to the queue.
- Object obj = writeQueue.poll();
- if (obj == null) {
- writeStateMachine.endWrite(WriteState.IDLE);
- }
- return obj;
- }
+ // Note: The checking of the queue for something to write and the
+ // calling of endWrite() if nothing is found must be kept
+ // within the same sync to avoid race conditions with adding
+ // entries to the queue.
+ return writeQueue.poll();
}
void addWrite(Object obj) {
- boolean needDispatch;
- synchronized (writeStateMachine) {
- writeQueue.add(obj);
- needDispatch = writeStateMachine.addWrite();
- }
- if (needDispatch) {
- socketWrapper.processSocket(SocketStatus.OPEN_WRITE, true);
- }
+ writeQueue.add(obj);
}
Modified: tomcat/trunk/java/org/apache/coyote/http2/Stream.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/coyote/http2/Stream.java?rev=1680910&r1=1680909&r2=1680910&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/coyote/http2/Stream.java (original)
+++ tomcat/trunk/java/org/apache/coyote/http2/Stream.java Thu May 21 15:31:43
2015
@@ -38,20 +38,29 @@ public class Stream extends AbstractStre
private final Response coyoteResponse = new Response();
private final StreamOutputBuffer outputBuffer = new StreamOutputBuffer();
- private volatile long flowControlWindowSize;
-
public Stream(Integer identifier, Http2UpgradeHandler handler) {
super(identifier);
this.handler = handler;
setParentStream(handler);
- flowControlWindowSize =
handler.getRemoteSettings().getInitialWindowSize();
+ setWindowSize(handler.getRemoteSettings().getInitialWindowSize());
coyoteResponse.setOutputBuffer(outputBuffer);
}
+ @Override
public void incrementWindowSize(int windowSizeIncrement) {
- flowControlWindowSize += windowSizeIncrement;
+ // If this is zero then any thread that has been trying to write for
+ // this stream will be waiting. Notify that thread it can continue. Use
+ // notify all even though only one thread is waiting to be on the safe
+ // side.
+ boolean notify = getWindowSize() == 0;
+ super.incrementWindowSize(windowSizeIncrement);
+ if (notify) {
+ synchronized (this) {
+ notifyAll();
+ }
+ }
}
@@ -176,11 +185,50 @@ public class Stream extends AbstractStre
}
public void flush() throws IOException {
+ if (!coyoteResponse.isCommitted()) {
+ coyoteResponse.sendHeaders();
+ }
if (buffer.position() == 0) {
// Buffer is empty. Nothing to do.
return;
}
- handler.writeBody(Stream.this, buffer);
+ buffer.flip();
+ int left = buffer.remaining();
+ int thisWriteStream;
+ while (left > 0) {
+ // Flow control for the Stream
+ do {
+ thisWriteStream = reserveWindowSize(left);
+ if (thisWriteStream < 1) {
+ // Need to block until a WindowUpdate message is
+ // processed for this stream;
+ synchronized (this) {
+ try {
+ wait();
+ } catch (InterruptedException e) {
+ // TODO. Possible shutdown?
+ }
+ }
+ }
+ } while (thisWriteStream < 1);
+
+ // Flow control for the connection
+ int thisWrite;
+ do {
+ thisWrite = handler.reserveWindowSize(thisWriteStream);
+ if (thisWrite < 1) {
+ // TODO Flow control when connection window is
exhausted
+ }
+ } while (thisWrite < 1);
+
+ decrementWindowSize(thisWrite);
+ handler.decrementWindowSize(thisWrite);
+
+ // Do the write
+ handler.writeBody(Stream.this, buffer, thisWrite);
+ left -= thisWrite;
+ buffer.position(buffer.position() + thisWrite);
+ }
buffer.clear();
}
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