checksum-dependency: reduce the number of idle threads

Previously, Executors.newFixedThreadPool created all the threads upfront

Author: vlsi

README.md

@@ -87,6 +87,9 @@ This library is distributed under terms of Apache License 2.0
 
 Change log
 ----------
+v1.89
+* checksum-dependency: reduce the number of idle threads
+
 v1.88
 * stage-vote-release: avoid failures when "init" does not exist
 * chore: fixed build warnings

plugins/checksum-dependency-plugin/README.md

@@ -501,6 +501,9 @@ Verification options
 
 Changelog
 ---------
+v1.89
+* Reduce the number of idle threads
+
 v1.88
 * Infer artifact classifier from the file name
 * Copy requested attributes to the configuration that resolves PGP signatures

plugins/checksum-dependency-plugin/src/main/kotlin/com/github/vlsi/gradle/checksum/Executors.kt

@@ -17,7 +17,9 @@
 package com.github.vlsi.gradle.checksum
 
 import java.util.concurrent.ExecutorService
-import java.util.concurrent.Executors
+import java.util.concurrent.LinkedBlockingQueue
+import java.util.concurrent.ThreadPoolExecutor
+import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicInteger
 
 class Executors(val cpu: ExecutorService, val io: ExecutorService) {
@@ -27,7 +29,11 @@ class Executors(val cpu: ExecutorService, val io: ExecutorService) {
 
 private fun pool(threads: Int, name: String): ExecutorService {
     val cnt = AtomicInteger()
-    return Executors.newFixedThreadPool(threads) {
+    return ThreadPoolExecutor(
+        0, threads,
+        20L, TimeUnit.SECONDS,
+        LinkedBlockingQueue()
+    ) { it: Runnable ->
         Thread(it).apply {
             this.name = name + cnt.getAndIncrement()
         }