[fix][fn] Fix Deadlock in Functions Worker LeaderService

[Technoboy-]

Fixes #21501

Motivation

No need to synchronized the method isLeader in LeaderService

See the deadlock stack :

"pulsar-external-listener-44525-1":
	at org.apache.pulsar.functions.worker.FunctionMetaDataManager.giveupLeadership(FunctionMetaDataManager.java)
	- waiting to lock <0x0000100013535c90> (a org.apache.pulsar.functions.worker.FunctionMetaDataManager)
	at org.apache.pulsar.functions.worker.LeaderService.becameInactive(LeaderService.java:167)
	- locked <0x000010001344c6d8> (a org.apache.pulsar.functions.worker.LeaderService)
	at org.apache.pulsar.client.impl.ConsumerImpl.lambda$activeConsumerChanged$27(ConsumerImpl.java:1136)
	at org.apache.pulsar.client.impl.ConsumerImpl$$Lambda$2606/0x00007f854ce9cb10.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@17.0.8.1/ThreadPoolExecutor.java:1136)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@17.0.8.1/ThreadPoolExecutor.java:635)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(java.base@17.0.8.1/Thread.java:833)
"pulsar-web-44514-6":
	at org.apache.pulsar.functions.worker.LeaderService.isLeader(LeaderService.java)
	- waiting to lock <0x000010001344c6d8> (a org.apache.pulsar.functions.worker.LeaderService)
	at org.apache.pulsar.functions.worker.SchedulerManager.scheduleInternal(SchedulerManager.java:200)
	at org.apache.pulsar.functions.worker.SchedulerManager.schedule(SchedulerManager.java:229)
	at org.apache.pulsar.functions.worker.FunctionMetaDataManager.updateFunctionOnLeader(FunctionMetaDataManager.java:251)
	- locked <0x0000100013535c90> (a org.apache.pulsar.functions.worker.FunctionMetaDataManager)
	at org.apache.pulsar.functions.worker.rest.api.ComponentImpl.internalProcessFunctionRequest(ComponentImpl.java:1775)
	at org.apache.pulsar.functions.worker.rest.api.ComponentImpl.updateRequest(ComponentImpl.java:996)
	at org.apache.pulsar.functions.worker.rest.api.FunctionsImpl.registerFunction(FunctionsImpl.java:222)
	at org.apache.pulsar.broker.admin.impl.FunctionsBase.registerFunction(FunctionsBase.java:196)

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[codecov-commenter]

Codecov Report

Merging #21711 (b0f8772) into master (495b141) will increase coverage by 36.63%.
Report is 2 commits behind head on master.
The diff coverage is 100.00%.

Additional details and impacted files

@@              Coverage Diff              @@
##             master   #21711       +/-   ##
=============================================
+ Coverage     36.75%   73.39%   +36.63%     
- Complexity    12271    32761    +20490     
=============================================
  Files          1717     1893      +176     
  Lines        131197   140714     +9517     
  Branches      14339    15502     +1163     
=============================================
+ Hits          48220   103270    +55050     
+ Misses        76596    29335    -47261     
- Partials       6381     8109     +1728     

Flag	Coverage Δ
inttests	24.10% <100.00%> (-0.01%)	⬇️
systests	24.79% <100.00%> (+0.01%)	⬆️
unittests	72.67% <100.00%> (+40.80%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
.../apache/pulsar/functions/worker/LeaderService.java	82.66% <100.00%> (+8.00%)	⬆️

... and 1463 files with indirect coverage changes