X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=folly%2FProducerConsumerQueue.h;h=16de57d35486a8207fcb1def59c48d59a1360fd3;hb=e89f46cd508ae85a0d0917119f5a73651e9af1b2;hp=12f2bf427c33ce9485ac393d42097f6b1a1a1741;hpb=05ce52289b0ec8f525a92d6d1955301d0b77c0a7;p=folly.git

diff --git a/folly/ProducerConsumerQueue.h b/folly/ProducerConsumerQueue.h
index 12f2bf42..16de57d3 100644
--- a/folly/ProducerConsumerQueue.h
+++ b/folly/ProducerConsumerQueue.h
@@ -35,7 +35,7 @@ namespace folly {
  * ProducerConsumerQueue is a one producer and one consumer queue
  * without locks.
  */
-template<class T>
+template <class T>
 struct ProducerConsumerQueue {
   typedef T value_type;
 
@@ -77,7 +77,7 @@ struct ProducerConsumerQueue {
     std::free(records_);
   }
 
-  template<class ...Args>
+  template <class... Args>
   bool write(Args&&... recordArgs) {
     auto const currentWrite = writeIndex_.load(std::memory_order_relaxed);
     auto nextRecord = currentWrite + 1;
@@ -167,15 +167,20 @@ struct ProducerConsumerQueue {
     return ret;
   }
 
-private:
- char pad0_[CacheLocality::kFalseSharingRange];
- const uint32_t size_;
- T* const records_;
+  // maximum number of items in the queue.
+  size_t capacity() const {
+    return size_ - 1;
+  }
+
+ private:
+  char pad0_[CacheLocality::kFalseSharingRange];
+  const uint32_t size_;
+  T* const records_;
 
- FOLLY_ALIGN_TO_AVOID_FALSE_SHARING std::atomic<unsigned int> readIndex_;
- FOLLY_ALIGN_TO_AVOID_FALSE_SHARING std::atomic<unsigned int> writeIndex_;
+  FOLLY_ALIGN_TO_AVOID_FALSE_SHARING std::atomic<unsigned int> readIndex_;
+  FOLLY_ALIGN_TO_AVOID_FALSE_SHARING std::atomic<unsigned int> writeIndex_;
 
- char pad1_[CacheLocality::kFalseSharingRange - sizeof(writeIndex_)];
+  char pad1_[CacheLocality::kFalseSharingRange - sizeof(writeIndex_)];
 };
 
-}
+} // namespace folly