From 72dabacbd1b69f29b8a92c5d6a9a51128d85a705 Mon Sep 17 00:00:00 2001
From: Jonathan L Long <jonlong@cs.berkeley.edu>
Date: Thu, 19 Mar 2015 22:29:25 -0700
Subject: [PATCH] add blocking_queue::wait_for_empty for blocking until done

---
 include/caffe/util/blocking_queue.hpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/caffe/util/blocking_queue.hpp b/include/caffe/util/blocking_queue.hpp
index 298ffc74163..09ee035d1cc 100644
--- a/include/caffe/util/blocking_queue.hpp
+++ b/include/caffe/util/blocking_queue.hpp
@@ -24,10 +24,20 @@ class blocking_queue {
     return queue_.empty();
   }
 
+  void wait_for_empty() {
+    boost::mutex::scoped_lock lock(mutex_);
+    while (!queue_.empty()) {
+      cond_empty_.wait(lock);
+    }
+  }
+
   T pop() {
     T t = peek();
     boost::mutex::scoped_lock lock(mutex_);
     queue_.pop();
+    if (queue_.empty()) {
+      cond_empty_.notify_all();
+    }
     return t;
   }
 
@@ -44,6 +54,7 @@ class blocking_queue {
   std::queue<T> queue_;
   mutable boost::mutex mutex_;
   boost::condition_variable cond_push_;
+  boost::condition_variable cond_empty_;
 
   DISABLE_COPY_AND_ASSIGN(blocking_queue);
 };