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Relates issue: NETTY-18 (Performance degradation when Channel.write() is called from outside an I/O thread (NIO transport)

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* Allowed a user to specify the NIO provider constraint level using the system property
* Added detectConstraintLevel() method to implement the constraint level autodetection
This commit is contained in:
Trustin Lee 2008-08-19 14:01:41 +00:00
parent 795b14a7b1
commit e53b802def
1 changed files with 47 additions and 3 deletions
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50
src/main/java/org/jboss/netty/channel/socket/nio/NioProviderMetadata.java
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@ -22,6 +22,9 @@
*/
package org.jboss.netty.channel.socket.nio;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
/**
* Provides information which is specific to a NIO service provider
* implementation.
@ -33,21 +36,62 @@ package org.jboss.netty.channel.socket.nio;
*
*/
class NioProviderMetadata {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(NioProviderMetadata.class);
private static final String CONSTRAINT_LEVEL_PROPERTY =
"java.nio.channels.spi.constraintLevel";
/**
* FIXME Auto-detect the level
*
* 0 - no need to wake up to get / set interestOps
* 1 - no need to wake up to get interestOps, but need to wake up to set.
* 2 - need to wake up to get / set interestOps
*/
static final int CONSTRAINT_LEVEL = 0;
static final int CONSTRAINT_LEVEL;
static {
int constraintLevel = -1;
// Use the system property if possible.
try {
String value = System.getProperty(CONSTRAINT_LEVEL_PROPERTY);
constraintLevel = Integer.parseInt(value);
if (constraintLevel < 0 || constraintLevel > 2) {
constraintLevel = -1;
} else {
logger.debug(
"Using the specified NIO constraint level: " +
constraintLevel);
}
} catch (Exception e) {
// format error or security issue
}
if (constraintLevel < 0) {
constraintLevel = detectConstraintLevel();
if (constraintLevel < 0) {
constraintLevel = 2;
logger.warn(
"Failed to autodetect the NIO constraint level; " +
"using the safest level (2)");
} else {
logger.debug(
"Using the autodected NIO constraint level: " +
constraintLevel);
}
}
CONSTRAINT_LEVEL = constraintLevel;
if (CONSTRAINT_LEVEL < 0 || CONSTRAINT_LEVEL > 2) {
throw new Error(
"Unexpected wakeup requirement level: " +
CONSTRAINT_LEVEL + ", please report this error.");
}
}
private static int detectConstraintLevel() {
// FIXME Auto-detect the level
return 0;
}
}