Merge remote-tracking branch 'couchbase/3.0.x' into sherlock

* couchbase/3.0.x:
  MB-19226: Address potential data races in the warmup code
  MB-19225: Fix data race on Flusher::taskId
  MB-19225: Fix race in Flusher._state
  MB-19224: Address possible data race with global task's waketime

Change-Id: Idc461799bc50bd1274f3ffafab4b3257a024327b

diff --cc src/executorthread.cc
Simple merge

diff --cc src/flusher.cc
index 9de7046,40da8ca..d4c6a61
--- 1/src/flusher.cc
--- 2/src/flusher.cc
+++ b/src/flusher.cc
@@@ -151,11 -150,8 +151,10 @@@ void Flusher::start() 
  }
  
  void Flusher::wake(void) {
-     LockHolder lh(taskMutex);
 -    cb_assert(taskId > 0);
 -    ExecutorPool::get()->wake(taskId);
 +    // taskId becomes zero if the flusher were stopped
 +    if (taskId > 0) {
 +        ExecutorPool::get()->wake(taskId);
 +    }
  }
  
  bool Flusher::step(GlobalTask *task) {

diff --cc src/taskqueue.cc
Simple merge

diff --cc src/tasks.cc
Simple merge

diff --cc src/tasks.h
Simple merge

diff --cc src/warmup.cc
Simple merge