Refactor application class

app/src/test/kotlin/org/koitharu/kotatsu/util/CompositeMutexTest.kt

@@ -0,0 +1,60 @@
+package org.koitharu.kotatsu.util
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.cancelAndJoin
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.withTimeout
+import kotlinx.coroutines.withTimeoutOrNull
+import kotlinx.coroutines.yield
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+import org.koitharu.kotatsu.core.util.CompositeMutex
+
+class CompositeMutexTest {
+
+	@Test
+	fun singleLock() = runTest {
+		val mutex = CompositeMutex<Int>()
+		mutex.lock(1)
+		mutex.lock(2)
+		mutex.unlock(1)
+		assert(mutex.size == 1)
+		mutex.unlock(2)
+		assert(mutex.isEmpty())
+	}
+
+	@Test
+	fun doubleLock() = runTest {
+		val mutex = CompositeMutex<Int>()
+		repeat(2) {
+			launch(Dispatchers.Default) {
+				mutex.lock(1)
+			}
+		}
+		yield()
+		assertEquals(1, mutex.size)
+		mutex.unlock(1)
+		val tryLock = withTimeoutOrNull(1000) {
+			mutex.lock(1)
+		}
+		assertNull(tryLock)
+	}
+
+	@Test
+	fun cancellation() = runTest {
+		val mutex = CompositeMutex<Int>()
+		mutex.lock(1)
+		val job = launch {
+			try {
+				mutex.lock(1)
+			} finally {
+				mutex.unlock(1)
+			}
+		}
+		withTimeout(2000) {
+			job.cancelAndJoin()
+		}
+	}
+}