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attribute/property transparency: really slow about javaserverfaces-spec HOT 11 CLOSED

javaee commented on September 23, 2024

attribute/property transparency: really slow

from javaserverfaces-spec.

Comments (11)

glassfishrobot commented on September 23, 2024

Reported by jayashri

from javaserverfaces-spec.

glassfishrobot commented on September 23, 2024

@edburns said:
The current impl is as fast as it can be given the best efforts of the
RI team and Adam to date.

Where is the bottleneck? It's in
UIComponentBase.getPropertyDescriptor(). This is called whenever
someone accesses a attribute or property on the UIComponent instance.
UIComponentBase.getAttributes().get(). This boils down to a get() on
a WeakHashMap that will return a PropertyDescriptor. This solution
assumes it is safe to have concurrent reads on the WeakHashMap. Is
the a safe assumption?

Is there a faster implementation? If not, can we design it
differently, while preserving backwards compatibility?

We need an automated test that reproduces this bug.

from javaserverfaces-spec.

glassfishrobot commented on September 23, 2024

@edburns said:
I've heard that this may be faster in JDK 1.4, and I would guess it might be
faster still in JDK 5.0?

from javaserverfaces-spec.

glassfishrobot commented on September 23, 2024

@edburns said:
This change-bundle fixes an unsafe assumption about the thread-safety of
unmodified WeakHashMap instances for concurrent reads.

SECTION: API Changes

M jsf-api/src/javax/faces/component/UIComponentBase.java

make pdMap ivar a Map, not a WeakHashMap
make pdMap ivar be vended by Collections.synchronizedMap().

SECTION: RI changes

M
jsf-ri/systest-per-webapp/el-performance/src/java/com/sun/faces/systest/EvaluatorBean.java

only wait for between 1 and 100 nanoseconds between get() operations.

SECTION: API Diffs

Index: jsf-api/src/javax/faces/component/UIComponentBase.java

RCS file:
/cvs/javaserverfaces-sources/jsf-api/src/javax/faces/component/UIComponentBase.java,v
retrieving revision 1.101
diff -u -r1.101 UIComponentBase.java
— jsf-api/src/javax/faces/component/UIComponentBase.java 16 Jun 2004
00:06:55 -0000 1.101
+++ jsf-api/src/javax/faces/component/UIComponentBase.java 15 Oct 2004 05:46:30
-0000
@@ -20,6 +20,7 @@
import java.util.AbstractSet;
import java.util.ArrayList;
import java.util.Collection;
+import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
@@ -75,7 +76,7 @@

Reference to the map of PropertyDescriptors for this class
in the descriptors Map. */



private WeakHashMap pdMap = null;

private Map pdMap = null;


/**


An empty argument list to be passed to reflection methods.
@@ -84,14 +85,14 @@


public UIComponentBase() {

synchronized(descriptors) {


pdMap = (WeakHashMap) descriptors.get(this.getClass());

pdMap = (Map) descriptors.get(this.getClass());

if (pdMap != null) { return; }

// load the property descriptors for this class.

PropertyDescriptor pd[] = getPropertyDescriptors();

if (pd != null) {


pdMap = new WeakHashMap(pd.length);

pdMap = Collections.synchronizedMap(new HashMap(pd.length));

for (int i = 0; i < pd.length; i++) { pdMap.put(pd[i].getName(), pd[i]); }



SECTION: RI Diffs
Index:

jsf-ri/systest-per-webapp/el-performance/src/java/com/sun/faces/systest/EvaluatorBean.java
RCS file:

/cvs/javaserverfaces-sources/jsf-ri/systest-per-webapp/el-performance/src/java/com/sun/faces/systest/EvaluatorBean.java,v

retrieving revision 1.3

diff -u -r1.3 EvaluatorBean.java

—

jsf-ri/systest-per-webapp/el-performance/src/java/com/sun/faces/systest/EvaluatorBean.java

14 Oct 2004 19:53:41 -0000 1.3

+++

jsf-ri/systest-per-webapp/el-performance/src/java/com/sun/faces/systest/EvaluatorBean.java

15 Oct 2004 05:46:34 -0000

@@ -120,7 +120,7 @@

curInput.getAttributes().put("foo", "bar");

runnable = new AttributeGetRunnable(curInput, getReps(), "foo",

random, i,

numThreads == 1 ? false: true,

true,

System.out,

this);



@@ -220,7 +220,7 @@
if (sleepBetweenGets) {

try
{ - Thread.sleep(Math.abs(random.nextLong()) % 10); + Thread.sleep(0L, Math.abs(random.nextInt()) % 100); }
catch (InterruptedException e) {

host.getThreadOutcomes()[index] = e;

from javaserverfaces-spec.

glassfishrobot commented on September 23, 2024

@edburns said:
Old implementation

30000 reps

1 thread