Allow time for processes to release file locks on windows

src/cache-gradle-user-home.ts

@@ -5,7 +5,7 @@ import * as core from '@actions/core'
 import * as glob from '@actions/glob'
 import * as exec from '@actions/exec'
 
-import {AbstractCache, hashFileNames} from './cache-utils'
+import {AbstractCache, hashFileNames, tryDelete} from './cache-utils'
 
 // Which paths under Gradle User Home should be cached
 const CACHE_PATH = ['caches', 'notifications']
@@ -141,7 +141,7 @@ export class GradleUserHomeCache extends AbstractCache {
         if (commonArtifactFiles.length === 0) {
             this.debug(`No files found to cache for ${bundle}`)
             if (fs.existsSync(cacheMetaFile)) {
-                fs.unlinkSync(cacheMetaFile)
+                tryDelete(cacheMetaFile)
             }
             return
         }
@@ -164,7 +164,7 @@ export class GradleUserHomeCache extends AbstractCache {
         }
 
         for (const file of commonArtifactFiles) {
-            fs.unlinkSync(file)
+            tryDelete(file)
         }
     }
 

src/cache-utils.ts

@@ -3,6 +3,7 @@ import * as cache from '@actions/cache'
 import * as github from '@actions/github'
 import * as crypto from 'crypto'
 import * as path from 'path'
+import * as fs from 'fs'
 
 export function isCacheDisabled(): boolean {
     return core.getBooleanInput('cache-disabled')
@@ -60,6 +61,29 @@ export function hashFileNames(fileNames: string[]): string {
     )
 }
 
+/**
+ * Attempt to delete a file, waiting to allow locks to be released
+ */
+export async function tryDelete(file: string): Promise<void> {
+    for (let count = 0; count < 3; count++) {
+        try {
+            fs.unlinkSync(file)
+            return
+        } catch (error) {
+            if (count === 2) {
+                throw error
+            } else {
+                core.warning(String(error))
+                await delay(1000)
+            }
+        }
+    }
+}
+
+async function delay(ms: number): Promise<void> {
+    return new Promise(resolve => setTimeout(resolve, ms))
+}
+
 class CacheKey {
     key: string
     restoreKeys: string[]