Don't use daemon threads in MockWebServer

This was a regression introduced with the TaskRunner changes.
I couldn't find other places where daemon threads were likely
to cause potential problems.

#5512

Author: squarejesse

mockwebserver/src/main/java/okhttp3/mockwebserver/MockWebServer.kt

@@ -98,7 +98,7 @@ import javax.net.ssl.X509TrustManager
  */
 class MockWebServer : ExternalResource(), Closeable {
   private val taskRunnerBackend = TaskRunner.RealBackend(
-      threadFactory("MockWebServer TaskRunner", true))
+      threadFactory("MockWebServer TaskRunner", daemon = false))
   private val taskRunner = TaskRunner(taskRunnerBackend)
   private val requestQueue = LinkedBlockingQueue<RecordedRequest>()
   private val openClientSockets =
@@ -391,10 +391,10 @@ class MockWebServer : ExternalResource(), Closeable {
 
     taskRunner.newQueue().execute("MockWebServer $portField", cancelable = false) {
       try {
-        logger.info("${this@MockWebServer} starting to accept connections")
+        logger.info("$this starting to accept connections")
         acceptConnections()
       } catch (e: Throwable) {
-        logger.log(Level.WARNING, "${this@MockWebServer}  failed unexpectedly", e)
+        logger.log(Level.WARNING, "$this failed unexpectedly", e)
       }
 
       // Release all sockets and all threads, even if any close fails.
@@ -468,10 +468,9 @@ class MockWebServer : ExternalResource(), Closeable {
       try {
         SocketHandler(raw).handle()
       } catch (e: IOException) {
-        logger.info("${this@MockWebServer} connection from ${raw.inetAddress} failed: $e")
+        logger.info("$this connection from ${raw.inetAddress} failed: $e")
       } catch (e: Exception) {
-        logger.log(Level.SEVERE,
-            "${this@MockWebServer} connection from ${raw.inetAddress} crashed", e)
+        logger.log(Level.SEVERE, "$this connection from ${raw.inetAddress} crashed", e)
       }
     }
   }

okhttp/src/main/java/okhttp3/internal/concurrent/TaskRunner.kt

@@ -18,6 +18,7 @@ package okhttp3.internal.concurrent
 import okhttp3.internal.addIfAbsent
 import okhttp3.internal.assertThreadDoesntHoldLock
 import okhttp3.internal.assertThreadHoldsLock
+import okhttp3.internal.concurrent.TaskRunner.Companion.INSTANCE
 import okhttp3.internal.notify
 import okhttp3.internal.threadFactory
 import java.util.concurrent.SynchronousQueue
@@ -28,9 +29,8 @@ import java.util.concurrent.TimeUnit
 /**
  * A set of worker threads that are shared among a set of task queues.
  *
- * The task runner is responsible for managing non-daemon threads. It keeps the process alive while
- * user-visible (ie. non-daemon) tasks are scheduled, and allows the process to exit when only
- * housekeeping (ie. daemon) tasks are scheduled.
+ * Use [INSTANCE] for a task runner that uses daemon threads. There is not currently a shared
+ * instance for non-daemon threads.
  *
  * The task runner is also responsible for releasing held threads when the library is unloaded.
  * This is for the benefit of container environments that implement code unloading.
@@ -289,6 +289,6 @@ class TaskRunner(
 
   companion object {
     @JvmField
-    val INSTANCE = TaskRunner(RealBackend(threadFactory("OkHttp TaskRunner", true)))
+    val INSTANCE = TaskRunner(RealBackend(threadFactory("OkHttp TaskRunner", daemon = true)))
   }
 }