Following is pipeline code

@NonCPS
def fn(){
def parallelArgs = [:]
new File('/home/jenkins/workspace/test_post_for_pipeline').eachFile() {
file ->
if (file.getName().endsWith('.properties')) {
parallelArgs["Run: $\{file.getName()}"] = {
build job: 'test', wait: true, parameters: [string(name: 'IN_PARAM_1', value: file.getAbsolutePath()), string(name: 'IN_PARAM_2', value: '2'), string(name: 'IN_PARAM_3', value: '3')]

}
}
}
parallel(parallelArgs)
}

node('master'){
fn()
}

Result: the build will hang forever. even downstream job test build done 
Started by user
Shuaibing Li
Replayed
[#121

https://jenkins-c.lombardrisk.com/job/test_post_for_pipeline/121/] [Pipeline] node Running on Jenkins in /home/jenkins/workspace/test_post_for_pipeline [Pipeline] { [Pipeline] parallel [Pipeline] [Run: a.properties] { (Branch: Run: a.properties) [Pipeline] [Run: a.properties] build (Building test) [Run: a.properties] Scheduling project: [test

https://jenkins-c.lombardrisk.com/job/test/] [Pipeline] [Run: b.properties] { (Branch: Run: b.properties) [Pipeline] [Run: a.properties] build (Building test) [Run: a.properties] Scheduling project: [test

https://jenkins-c.lombardrisk.com/job/test/] [Run: a.properties] Starting building: test #313