3 files changed, 16 insertions, 3 deletions
diff --git a/unsupported/Eigen/CXX11/src/ThreadPool/EventCount.h b/unsupported/Eigen/CXX11/src/ThreadPool/EventCount.h
index 12b80d6c4..71d55552d 100644
--- a/unsupported/Eigen/CXX11/src/ThreadPool/EventCount.h
+++ b/unsupported/Eigen/CXX11/src/ThreadPool/EventCount.h
@@ -50,7 +50,7 @@ class EventCount {
  public:
   class Waiter;
 
-  EventCount(std::vector<Waiter>& waiters) : waiters_(waiters) {
+  EventCount(MaxSizeVector<Waiter>& waiters) : waiters_(waiters) {
     eigen_assert(waiters.size() < (1 << kWaiterBits) - 1);
     // Initialize epoch to something close to overflow to test overflow.
     state_ = kStackMask | (kEpochMask - kEpochInc * waiters.size() * 2);
@@ -199,7 +199,7 @@ class EventCount {
   static const uint64_t kEpochMask = ((1ull << kEpochBits) - 1) << kEpochShift;
   static const uint64_t kEpochInc = 1ull << kEpochShift;
   std::atomic<uint64_t> state_;
-  std::vector<Waiter>& waiters_;
+  MaxSizeVector<Waiter>& waiters_;
 
   void Park(Waiter* w) {
     std::unique_lock<std::mutex> lock(w->mu);
diff --git a/unsupported/Eigen/CXX11/src/ThreadPool/NonBlockingThreadPool.h b/unsupported/Eigen/CXX11/src/ThreadPool/NonBlockingThreadPool.h
index 33ae45131..354bce52a 100644
--- a/unsupported/Eigen/CXX11/src/ThreadPool/NonBlockingThreadPool.h
+++ b/unsupported/Eigen/CXX11/src/ThreadPool/NonBlockingThreadPool.h
@@ -29,6 +29,8 @@ class NonBlockingThreadPoolTempl : public Eigen::ThreadPoolInterface {
         spinning_(0),
         done_(false),
         ec_(waiters_) {
+    waiters_.resize(num_threads);
+
     // Calculate coprimes of num_threads.
     // Coprimes are used for a random walk over all threads in Steal
     // and NonEmptyQueueIndex. Iteration is based on the fact that if we take
@@ -123,7 +125,7 @@ class NonBlockingThreadPoolTempl : public Eigen::ThreadPoolInterface {
   MaxSizeVector<Thread*> threads_;
   MaxSizeVector<Queue*> queues_;
   MaxSizeVector<unsigned> coprimes_;
-  std::vector<EventCount::Waiter> waiters_;
+  MaxSizeVector<EventCount::Waiter> waiters_;
   std::atomic<unsigned> blocked_;
   std::atomic<bool> spinning_;
   std::atomic<bool> done_;
diff --git a/unsupported/Eigen/CXX11/src/util/MaxSizeVector.h b/unsupported/Eigen/CXX11/src/util/MaxSizeVector.h
index 961456f10..4bc3dd1ba 100644
--- a/unsupported/Eigen/CXX11/src/util/MaxSizeVector.h
+++ b/unsupported/Eigen/CXX11/src/util/MaxSizeVector.h
@@ -55,6 +55,17 @@ class MaxSizeVector {
     internal::aligned_free(data_);
   }
 
+  void resize(size_t n) {
+    eigen_assert(n <= reserve_);
+    for (size_t i = size_; i < n; ++i) {
+      new (&data_[i]) T;
+    }
+    for (size_t i = n; i < size_; ++i) {
+      data_[i].~T();
+    }
+    size_ = n;
+  }
+
   // Append new elements (up to reserved size).
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
   void push_back(const T& t) {