This is an automated email from the ASF dual-hosted git repository.
markt pushed a commit to branch 9.0.x
in repository https://gitbox.apache.org/repos/asf/tomcat.git
The following commit(s) were added to refs/heads/9.0.x by this push:
new 170e0f7 Improve the recycling of Processor objects to make it more
robust.
170e0f7 is described below
commit 170e0f792bd18ff031677890ba2fe50eb7a376c1
Author: Mark Thomas <ma...@apache.org>
AuthorDate: Tue Mar 29 19:15:37 2022 +0100
Improve the recycling of Processor objects to make it more robust.
---
java/org/apache/coyote/AbstractProtocol.java | 32 ++++++++++++----------
.../apache/tomcat/util/net/SocketWrapperBase.java | 17 ++++++++----
webapps/docs/changelog.xml | 4 +++
3 files changed, 33 insertions(+), 20 deletions(-)
diff --git a/java/org/apache/coyote/AbstractProtocol.java
b/java/org/apache/coyote/AbstractProtocol.java
index 4f854b9..562daec 100644
--- a/java/org/apache/coyote/AbstractProtocol.java
+++ b/java/org/apache/coyote/AbstractProtocol.java
@@ -797,7 +797,11 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
S socket = wrapper.getSocket();
- Processor processor = (Processor) wrapper.getCurrentProcessor();
+ // We take complete ownership of the Processor inside of this
method to ensure
+ // no other thread can release it while we're using it. Whatever
processor is
+ // held by this variable will be associated with the SocketWrapper
before this
+ // method returns.
+ Processor processor = (Processor) wrapper.takeCurrentProcessor();
if (getLog().isDebugEnabled()) {
getLog().debug(sm.getString("abstractConnectionHandler.connectionsGet",
processor, socket));
@@ -881,9 +885,6 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
processor.setSslSupport(
wrapper.getSslSupport(getProtocol().getClientCertProvider()));
- // Associate the processor with the connection
- wrapper.setCurrentProcessor(processor);
-
SocketState state = SocketState.CLOSED;
do {
state = processor.process(wrapper, status);
@@ -903,8 +904,6 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
release(processor);
// Create the upgrade processor
processor =
upgradeProtocol.getProcessor(wrapper, getProtocol().getAdapter());
- // Associate with the processor with the
connection
- wrapper.setCurrentProcessor(processor);
} else {
if (getLog().isDebugEnabled()) {
getLog().debug(sm.getString(
@@ -924,8 +923,6 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
getLog().debug(sm.getString("abstractConnectionHandler.upgradeCreate",
processor, wrapper));
}
- // Associate with the processor with the connection
- wrapper.setCurrentProcessor(processor);
// Initialise the upgrade handler (which may
trigger
// some IO using the new protocol which is why the
lines
// above are necessary)
@@ -963,8 +960,8 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
} else if (state == SocketState.OPEN) {
// In keep-alive but between requests. OK to recycle
// processor. Continue to poll for the next request.
- wrapper.setCurrentProcessor(null);
release(processor);
+ processor = null;
wrapper.registerReadInterest();
} else if (state == SocketState.SENDFILE) {
// Sendfile in progress. If it fails, the socket will be
@@ -989,8 +986,7 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
// Connection closed. OK to recycle the processor.
// Processors handling upgrades require additional clean-up
// before release.
- wrapper.setCurrentProcessor(null);
- if (processor.isUpgrade()) {
+ if (processor != null && processor.isUpgrade()) {
UpgradeToken upgradeToken =
processor.getUpgradeToken();
HttpUpgradeHandler httpUpgradeHandler =
upgradeToken.getHttpUpgradeHandler();
InstanceManager instanceManager =
upgradeToken.getInstanceManager();
@@ -1011,7 +1007,13 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
}
}
}
+
release(processor);
+ processor = null;
+ }
+
+ if (processor != null) {
+ wrapper.setCurrentProcessor(processor);
}
return state;
} catch(java.net.SocketException e) {
@@ -1047,7 +1049,6 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
// Make sure socket/processor is removed from the list of current
// connections
- wrapper.setCurrentProcessor(null);
release(processor);
return SocketState.CLOSED;
}
@@ -1081,7 +1082,9 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
/**
* Expected to be used by the handler once the processor is no longer
- * required.
+ * required. Care must be taken to ensure that this method is only
+ * called once per processor, after the request processing has
+ * completed.
*
* @param processor Processor being released (that was associated with
* the socket)
@@ -1119,8 +1122,7 @@ public abstract class AbstractProtocol<S> implements
ProtocolHandler,
*/
@Override
public void release(SocketWrapperBase<S> socketWrapper) {
- Processor processor = (Processor)
socketWrapper.getCurrentProcessor();
- socketWrapper.setCurrentProcessor(null);
+ Processor processor = (Processor)
socketWrapper.takeCurrentProcessor();
release(processor);
}
diff --git a/java/org/apache/tomcat/util/net/SocketWrapperBase.java
b/java/org/apache/tomcat/util/net/SocketWrapperBase.java
index 81a89e3..3c1da33 100644
--- a/java/org/apache/tomcat/util/net/SocketWrapperBase.java
+++ b/java/org/apache/tomcat/util/net/SocketWrapperBase.java
@@ -29,6 +29,7 @@ import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
@@ -106,10 +107,12 @@ public abstract class SocketWrapperBase<E> {
protected volatile OperationState<?> writeOperation = null;
/**
- * The org.apache.coyote.Processor instance currently associated
- * with the wrapper.
+ * The org.apache.coyote.Processor instance currently associated with the
+ * wrapper. Only populated when required to maintain wrapper<->Processor
+ * mapping between calls to
+ * {@link AbstractEndpoint.Handler#process(SocketWrapperBase,
SocketEvent)}.
*/
- protected Object currentProcessor = null;
+ private final AtomicReference<Object> currentProcessor = new
AtomicReference<>();
public SocketWrapperBase(E socket, AbstractEndpoint<E,?> endpoint) {
this.socket = socket;
@@ -136,11 +139,15 @@ public abstract class SocketWrapperBase<E> {
}
public Object getCurrentProcessor() {
- return currentProcessor;
+ return currentProcessor.get();
}
public void setCurrentProcessor(Object currentProcessor) {
- this.currentProcessor = currentProcessor;
+ this.currentProcessor.set(currentProcessor);
+ }
+
+ public Object takeCurrentProcessor() {
+ return currentProcessor.getAndSet(null);
}
/**
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 8227405..f2da703 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -138,6 +138,10 @@
with TLS 1.3 but the JSSE TLS 1.3 implementation does not support PHA.
(markt)
</add>
+ <fix>
+ Improve the recycling of Processor objects to make it more robust.
+ (markt)
+ </fix>
</changelog>
</subsection>
<subsection name="Jasper">
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