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Merged
merged 2 commits into from
Sep 6, 2025
Merged

Properly synchronize access to httpClientBuilder_ #1015

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c4489a5
Properly synchronize access to httpClientBuilder_
rschwietzke Sep 5, 2025
8da827b
Make the synchronization nicer
rschwietzke Sep 6, 2025
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12 changes: 8 additions & 4 deletions src/main/java/org/htmlunit/HttpWebConnection.java
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Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,7 @@
private static final String HACKED_COOKIE_POLICY = "mine";

// have one per thread because this is (re)configured for every call (see configureHttpProcessorBuilder)
// do not use a ThreadLocal because this in only accessed form this class
// do not use a ThreadLocal because this in only accessed form this class, but we still need it synchronized
private final Map<Thread, HttpClientBuilder> httpClientBuilder_ = new WeakHashMap<>();
private final WebClient webClient_;

Expand Down Expand Up @@ -211,7 +211,9 @@
// Calling code may catch the StackOverflowError, but due to the leak, the httpClient_ may
// come out of connections and throw a ConnectionPoolTimeoutException.
// => best solution, discard the HttpClient instance.
httpClientBuilder_.remove(Thread.currentThread());
synchronized (httpClientBuilder_) {

Check warning on line 214 in src/main/java/org/htmlunit/HttpWebConnection.java

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[PMD] reported by reviewdog 🐶
Use ReentrantLock rather than synchronization

Raw Output:
{"level":"warning","locations":[{"physicalLocation":{"artifactLocation":{"uri":"file:///home/runner/work/htmlunit/htmlunit/src/main/java/org/htmlunit/HttpWebConnection.java"},"region":{"endColumn":18,"endLine":216,"startColumn":17,"startLine":214}}}],"message":{"text":"Use ReentrantLock rather than synchronization"},"ruleId":"AvoidSynchronizedStatement","ruleIndex":4}
httpClientBuilder_.remove(Thread.currentThread());

Check warning on line 215 in src/main/java/org/htmlunit/HttpWebConnection.java

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[PMD] reported by reviewdog 🐶
To be compliant to J2EE, a webapp should not use any thread.

Raw Output:
{"level":"warning","locations":[{"physicalLocation":{"artifactLocation":{"uri":"file:///home/runner/work/htmlunit/htmlunit/src/main/java/org/htmlunit/HttpWebConnection.java"},"region":{"endColumn":53,"endLine":215,"startColumn":47,"startLine":215}}}],"message":{"text":"To be compliant to J2EE, a webapp should not use any thread."},"ruleId":"DoNotUseThreads","ruleIndex":13}
}
throw e;
}
}
Expand Down Expand Up @@ -530,7 +532,7 @@
*
* @return the initialized HTTP client
*/
protected HttpClientBuilder getHttpClientBuilder() {
protected synchronized HttpClientBuilder getHttpClientBuilder() {

Check warning on line 535 in src/main/java/org/htmlunit/HttpWebConnection.java

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[PMD] reported by reviewdog 🐶
Use block level locking rather than method level synchronization

Raw Output:
{"level":"warning","locations":[{"physicalLocation":{"artifactLocation":{"uri":"file:///home/runner/work/htmlunit/htmlunit/src/main/java/org/htmlunit/HttpWebConnection.java"},"region":{"endColumn":66,"endLine":535,"startColumn":46,"startLine":535}}}],"message":{"text":"Use block level locking rather than method level synchronization"},"ruleId":"AvoidSynchronizedAtMethodLevel","ruleIndex":5}
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@rbri rbri Sep 6, 2025

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@rschwietzke is this correct, in the other cases we sync on the httpClientBuilder_ object and in this case on the HttpWebConnection. My guess is we should always sync on the httpClientBuilder_.

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@rschwietzke rschwietzke Sep 6, 2025

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You are right. That was not fully correct, but might have worked somehow. ;) PR updates

final Thread currentThread = Thread.currentThread();
HttpClientBuilder builder = httpClientBuilder_.get(currentThread);
if (builder == null) {
Expand Down Expand Up @@ -1288,7 +1290,9 @@
*/
@Override
public void close() {
httpClientBuilder_.clear();
synchronized (httpClientBuilder_) {

Check warning on line 1293 in src/main/java/org/htmlunit/HttpWebConnection.java

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GitHub Actions / PMD 

[PMD] reported by reviewdog 🐶
Use ReentrantLock rather than synchronization

Raw Output:
{"level":"warning","locations":[{"physicalLocation":{"artifactLocation":{"uri":"file:///home/runner/work/htmlunit/htmlunit/src/main/java/org/htmlunit/HttpWebConnection.java"},"region":{"endColumn":10,"endLine":1295,"startColumn":9,"startLine":1293}}}],"message":{"text":"Use ReentrantLock rather than synchronization"},"ruleId":"AvoidSynchronizedStatement","ruleIndex":4}
httpClientBuilder_.clear();
}
sharedAuthCache_.clear();
httpClientContextByThread_.clear();

Expand Down