Merge "Move dumpsys to handler thread" into main

tests/unit/java/com/android/server/HandlerUtilsTest.kt

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server
+
+import android.os.HandlerThread
+import com.android.server.connectivity.HandlerUtils
+import com.android.testutils.DevSdkIgnoreRunner
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+import org.junit.After
+import org.junit.Test
+import org.junit.runner.RunWith
+
+const val THREAD_BLOCK_TIMEOUT_MS = 1000L
+const val TEST_REPEAT_COUNT = 100
+@RunWith(DevSdkIgnoreRunner::class)
+class HandlerUtilsTest {
+    val handlerThread = HandlerThread("HandlerUtilsTestHandlerThread").also {
+        it.start()
+    }
+    val handler = handlerThread.threadHandler
+
+    @Test
+    fun testRunWithScissors() {
+        // Repeat the test a fair amount of times to ensure that it does not pass by chance.
+        repeat(TEST_REPEAT_COUNT) {
+            var result = false
+            HandlerUtils.runWithScissors(handler, {
+                assertEquals(Thread.currentThread(), handlerThread)
+                result = true
+            }, THREAD_BLOCK_TIMEOUT_MS)
+            // Assert that the result is modified on the handler thread, but can also be seen from
+            // the current thread. The assertion should pass if the runWithScissors provides
+            // the guarantee where the assignment happens-before the assertion.
+            assertTrue(result)
+        }
+    }
+
+    @After
+    fun tearDown() {
+        handlerThread.quitSafely()
+        handlerThread.join()
+    }
+}