From 88238a240661e45f6d2bf58e906a60ea0552f65c Mon Sep 17 00:00:00 2001
From: Ricki Hirner <hirner@bitfire.at>
Date: Wed, 20 Dec 2023 14:34:04 +0100
Subject: [PATCH] ConcurrentUtilsTest: fix testRunSingle_SameKey_Parallel
 (bitfireAT/davx5#494)

ConcurrentUtilsTest: changed testRunSingle_SameKey_Parallel to testRunSingle_SameKey_Nested
---
 .../bitfire/davdroid/ConcurrentUtilsTest.kt   | 33 +++++++++++--------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/app/src/test/kotlin/at/bitfire/davdroid/ConcurrentUtilsTest.kt b/app/src/test/kotlin/at/bitfire/davdroid/ConcurrentUtilsTest.kt
index c302ab04..db7af612 100644
--- a/app/src/test/kotlin/at/bitfire/davdroid/ConcurrentUtilsTest.kt
+++ b/app/src/test/kotlin/at/bitfire/davdroid/ConcurrentUtilsTest.kt
@@ -6,8 +6,12 @@ package at.bitfire.davdroid
 
 import at.bitfire.davdroid.util.ConcurrentUtils
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Assert.fail
 import org.junit.Test
 import java.util.concurrent.atomic.AtomicInteger
+import kotlin.concurrent.thread
 
 class ConcurrentUtilsTest {
 
@@ -24,12 +28,12 @@ class ConcurrentUtilsTest {
         var nrCalled = AtomicInteger()
         val threads = mutableListOf<Thread>()
         for (i in 0 until 10)
-            threads += Thread() {
+            threads += thread {
                 ConcurrentUtils.runSingle(i) {
                     nrCalled.incrementAndGet()
                     Thread.sleep(100)
                 }
-            }.apply { start() }
+            }
         threads.forEach { it.join() }
         assertEquals(10, nrCalled.get())
     }
@@ -44,19 +48,20 @@ class ConcurrentUtilsTest {
     }
 
     @Test
-    fun testRunSingle_SameKey_Parallel() {
+    fun testRunSingle_SameKey_Nested() {
         val key = "a"
-        val nrCalled = AtomicInteger()
-        val threads = mutableListOf<Thread>()
-        for (i in 0 until 10)
-            threads += Thread() {
-                ConcurrentUtils.runSingle(key) {
-                    nrCalled.incrementAndGet()
-                    Thread.sleep(100)
-                }
-            }.apply { start() }
-        threads.forEach { it.join() }
-        assertEquals(1, nrCalled.get())
+
+        var outerBlockExecuted = false
+        ConcurrentUtils.runSingle(key) {
+            outerBlockExecuted = true
+
+            // Now a code block with the key is already running, further ones should be ignored
+            assertFalse(ConcurrentUtils.runSingle(key) {
+                fail("Shouldn't have been called")
+            })
+        }
+
+        assertTrue(outerBlockExecuted)
     }
 
 }
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