/guava/guava/src/com/google/common/util/concurrent/ExecutionSequencer.java
executingTaskQueue.nextTask = null;executingTaskQueue.nextExecutor = null;
executingTaskQueue.nextExecutor = null;
localTask.run(); Runnable queuedTask; Executor queuedExecutor; while ((queuedTask = executingTaskQueue.nextTask) != null && (queuedExecutor = executingTaskQueue.nextExecutor) != null) { executingTaskQueue.nextTask = null; <extra_id_0> queuedExecutor.execute(queuedTask); } } finally { executingTaskQueue.thread = null; } }