Fix AsyncAppender/SocketAppender unit tests

AsyncAppenderBaseTest: The appender was not allowed enough time to
flush the appender on #stop(), causing the empty-check of the appender's
queue to fail. The test appender's max-flush time is now extended from
30ms to >1000ms.

AbstractSocketAppenderIntegrationTest: A unit test expected
deque.takeFirst() to be called only once after a log-event is appended,
but the call actually occurs twice in a while-loop, where the second
call is intended to block, waiting for the next log-event.

AbstractSocketAppenderTest: A unit test that verified appender
behavior when its deque was at capacity neglected to fill the deque
before testing for errors.

logback-core/src/test/java/ch/qos/logback/core/AsyncAppenderBaseTest.java

@@ -162,7 +162,7 @@ public void invalidQueueCapacityShouldResultInNonStartedAppender() {
   @Test
   public void workerThreadFlushesOnStop() {
     int loopLen = 5;
-    int maxRuntime = (loopLen + 1) * delayingListAppender.delay;
+    int maxRuntime = (loopLen + 1) * Math.max(1000, delayingListAppender.delay);
     ListAppender la = delayingListAppender;
     asyncAppenderBase.addAppender(la);
     asyncAppenderBase.setDiscardingThreshold(0);

logback-core/src/test/java/ch/qos/logback/core/net/AbstractSocketAppenderIntegrationTest.java

@@ -89,7 +89,7 @@ public void dispatchesEvents() throws Exception {
     instrumentedAppender.append("some event");
 
     // wait for event to be taken from deque and being written into the stream
-    verify(deque, timeout(TIMEOUT)).takeFirst();
+    verify(deque, timeout(TIMEOUT).atLeastOnce()).takeFirst();
     verify(objectWriter, timeout(TIMEOUT)).write("some event");
 
     // then

logback-core/src/test/java/ch/qos/logback/core/net/AbstractSocketAppenderTest.java

@@ -392,11 +392,16 @@ public void addsInfoMessageWhenEventIsBeingDroppedBecauseOfConnectionProblemAndD
 
     // given
     doThrow(new IOException()).when(objectWriter).write(anyObject());
-    doThrow(new IllegalStateException()).when(deque).offerFirst("some event");
     appender.start();
     awaitStartOfEventDispatching();
     reset(appender);
 
+    // fill up deque
+    int max = deque.remainingCapacity();
+    for (int i = 0; i < max; i++) {
+      deque.offer(""+i);
+    }
+
     // when
     appender.append("some event");