diff --git a/core/CMakeLists.txt b/core/CMakeLists.txt
index 58dbd38..333742d 100644
--- a/core/CMakeLists.txt
+++ b/core/CMakeLists.txt
@@ -16,6 +16,8 @@ set_property(TARGET core PROPERTY POSITION_INDEPENDENT_CODE ON)
 if(AARE_TESTS)
     set(TestSources
             ${CMAKE_CURRENT_SOURCE_DIR}/src/defs.test.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/src/ProducerConsumerQueue.test.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/src/CircularFifo.test.cpp
         )
     target_sources(tests PRIVATE ${TestSources} )
     target_link_libraries(tests PRIVATE core)
diff --git a/core/include/aare/CircularFifo.hpp b/core/include/aare/CircularFifo.hpp
new file mode 100644
index 0000000..9c01b9a
--- /dev/null
+++ b/core/include/aare/CircularFifo.hpp
@@ -0,0 +1,112 @@
+#pragma once
+
+#include <chrono>
+#include <fmt/color.h>
+#include <fmt/format.h>
+#include <memory>
+#include <thread>
+
+#include "aare/ProducerConsumerQueue.hpp"
+
+namespace aare {
+
+template <class ItemType> class CircularFifo {
+    uint32_t fifo_size;
+    folly::ProducerConsumerQueue<ItemType> free_slots;
+    folly::ProducerConsumerQueue<ItemType> filled_slots;
+  
+  public:
+    CircularFifo() : CircularFifo(100){};
+    CircularFifo(uint32_t size)
+        : fifo_size(size), free_slots(size+1), filled_slots(size+1) {
+
+        // TODO! how do we deal with alignment for writing? alignas???
+        // Do we give the user a chance to provide memory locations? 
+        // Templated allocator?
+        for (size_t i = 0; i < fifo_size; ++i) {
+            free_slots.write(ItemType{});
+        }
+    }
+
+    bool next(){
+        //TODO! avoid default constructing ItemType
+      ItemType it;
+      if(!filled_slots.read(it))
+        return false;
+      if(!free_slots.write(std::move(it)))
+        return false;
+      return true;
+
+    }
+
+    ~CircularFifo() {}
+
+    using value_type = ItemType;
+
+    auto numFilledSlots() const noexcept { return filled_slots.sizeGuess(); }
+    auto numFreeSlots() const noexcept { return free_slots.sizeGuess(); }
+    auto isFull() const noexcept { return filled_slots.isFull(); }
+
+ItemType pop_free() {
+    ItemType v;
+    while (!free_slots.read(v))
+        ;
+    return std::move(v);
+    // return v;
+}
+
+bool try_pop_free(ItemType& v){
+    return free_slots.read(v);
+}
+
+ItemType pop_value(std::chrono::nanoseconds wait,
+                               std::atomic<bool> &stopped) {
+    ItemType v;
+    while (!filled_slots.read(v) && !stopped) {
+        std::this_thread::sleep_for(wait);
+    }
+    return std::move(v);
+}
+
+ItemType pop_value() {
+    ItemType v;
+    while (!filled_slots.read(v))
+        ;
+    return std::move(v);
+}
+
+ItemType* frontPtr(){
+  return filled_slots.frontPtr();
+}
+
+// TODO! Add function to move item from filled to free to be used
+// with the frontPtr function
+
+
+template <class... Args>
+void push_value(Args&&... recordArgs) {
+    while (!filled_slots.write(std::forward<Args>(recordArgs)...))
+        ;
+}
+
+template <class... Args>
+bool try_push_value(Args&&... recordArgs) {
+    return filled_slots.write(std::forward<Args>(recordArgs)...);
+
+}
+
+template <class... Args>
+void push_free(Args&&... recordArgs) {
+    while (!free_slots.write(std::forward<Args>(recordArgs)...))
+        ;
+}
+
+template <class... Args>
+bool try_push_free(Args&&... recordArgs) {
+    return free_slots.write(std::forward<Args>(recordArgs)...);
+
+}
+
+};
+
+} // namespace aare
\ No newline at end of file
diff --git a/core/include/aare/ProducerConsumerQueue.hpp b/core/include/aare/ProducerConsumerQueue.hpp
new file mode 100644
index 0000000..b10c327
--- /dev/null
+++ b/core/include/aare/ProducerConsumerQueue.hpp
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// @author Bo Hu (bhu@fb.com)
+// @author Jordan DeLong (delong.j@fb.com)
+
+// Changes made by PSD Detector Group:
+// Copied: Line 34 constexpr std::size_t hardware_destructive_interference_size = 128; from folly/lang/Align.h
+// Changed extension to .hpp
+
+#pragma once
+
+#include <atomic>
+#include <cassert>
+#include <cstdlib>
+#include <memory>
+#include <stdexcept>
+#include <type_traits>
+#include <utility>
+
+constexpr std::size_t hardware_destructive_interference_size = 128; 
+namespace folly {
+
+/*
+ * ProducerConsumerQueue is a one producer and one consumer queue
+ * without locks.
+ */
+template <class T>
+struct ProducerConsumerQueue {
+  typedef T value_type;
+
+  ProducerConsumerQueue(const ProducerConsumerQueue&) = delete;
+  ProducerConsumerQueue& operator=(const ProducerConsumerQueue&) = delete;
+
+  // size must be >= 2.
+  //
+  // Also, note that the number of usable slots in the queue at any
+  // given time is actually (size-1), so if you start with an empty queue,
+  // isFull() will return true after size-1 insertions.
+  explicit ProducerConsumerQueue(uint32_t size)
+      : size_(size),
+        records_(static_cast<T*>(std::malloc(sizeof(T) * size))),
+        readIndex_(0),
+        writeIndex_(0) {
+    assert(size >= 2);
+    if (!records_) {
+      throw std::bad_alloc();
+    }
+  }
+
+  ~ProducerConsumerQueue() {
+    // We need to destruct anything that may still exist in our queue.
+    // (No real synchronization needed at destructor time: only one
+    // thread can be doing this.)
+    if (!std::is_trivially_destructible<T>::value) {
+      size_t readIndex = readIndex_;
+      size_t endIndex = writeIndex_;
+      while (readIndex != endIndex) {
+        records_[readIndex].~T();
+        if (++readIndex == size_) {
+          readIndex = 0;
+        }
+      }
+    }
+
+    std::free(records_);
+  }
+
+  template <class... Args>
+  bool write(Args&&... recordArgs) {
+    auto const currentWrite = writeIndex_.load(std::memory_order_relaxed);
+    auto nextRecord = currentWrite + 1;
+    if (nextRecord == size_) {
+      nextRecord = 0;
+    }
+    if (nextRecord != readIndex_.load(std::memory_order_acquire)) {
+      new (&records_[currentWrite]) T(std::forward<Args>(recordArgs)...);
+      writeIndex_.store(nextRecord, std::memory_order_release);
+      return true;
+    }
+
+    // queue is full
+    return false;
+  }
+
+  // move (or copy) the value at the front of the queue to given variable
+  bool read(T& record) {
+    auto const currentRead = readIndex_.load(std::memory_order_relaxed);
+    if (currentRead == writeIndex_.load(std::memory_order_acquire)) {
+      // queue is empty
+      return false;
+    }
+
+    auto nextRecord = currentRead + 1;
+    if (nextRecord == size_) {
+      nextRecord = 0;
+    }
+    record = std::move(records_[currentRead]);
+    records_[currentRead].~T();
+    readIndex_.store(nextRecord, std::memory_order_release);
+    return true;
+  }
+
+  // pointer to the value at the front of the queue (for use in-place) or
+  // nullptr if empty.
+  T* frontPtr() {
+    auto const currentRead = readIndex_.load(std::memory_order_relaxed);
+    if (currentRead == writeIndex_.load(std::memory_order_acquire)) {
+      // queue is empty
+      return nullptr;
+    }
+    return &records_[currentRead];
+  }
+
+  // queue must not be empty
+  void popFront() {
+    auto const currentRead = readIndex_.load(std::memory_order_relaxed);
+    assert(currentRead != writeIndex_.load(std::memory_order_acquire));
+
+    auto nextRecord = currentRead + 1;
+    if (nextRecord == size_) {
+      nextRecord = 0;
+    }
+    records_[currentRead].~T();
+    readIndex_.store(nextRecord, std::memory_order_release);
+  }
+
+  bool isEmpty() const {
+    return readIndex_.load(std::memory_order_acquire) ==
+        writeIndex_.load(std::memory_order_acquire);
+  }
+
+  bool isFull() const {
+    auto nextRecord = writeIndex_.load(std::memory_order_acquire) + 1;
+    if (nextRecord == size_) {
+      nextRecord = 0;
+    }
+    if (nextRecord != readIndex_.load(std::memory_order_acquire)) {
+      return false;
+    }
+    // queue is full
+    return true;
+  }
+
+  // * If called by consumer, then true size may be more (because producer may
+  //   be adding items concurrently).
+  // * If called by producer, then true size may be less (because consumer may
+  //   be removing items concurrently).
+  // * It is undefined to call this from any other thread.
+  size_t sizeGuess() const {
+    int ret = writeIndex_.load(std::memory_order_acquire) -
+        readIndex_.load(std::memory_order_acquire);
+    if (ret < 0) {
+      ret += size_;
+    }
+    return ret;
+  }
+
+  // maximum number of items in the queue.
+  size_t capacity() const { return size_ - 1; }
+
+ private:
+  using AtomicIndex = std::atomic<unsigned int>;
+
+  char pad0_[hardware_destructive_interference_size];
+  const uint32_t size_;
+  T* const records_;
+
+  alignas(hardware_destructive_interference_size) AtomicIndex readIndex_;
+  alignas(hardware_destructive_interference_size) AtomicIndex writeIndex_;
+
+  char pad1_[hardware_destructive_interference_size - sizeof(AtomicIndex)];
+};
+
+} // namespace folly
\ No newline at end of file
diff --git a/core/src/CircularFifo.test.cpp b/core/src/CircularFifo.test.cpp
new file mode 100644
index 0000000..973142a
--- /dev/null
+++ b/core/src/CircularFifo.test.cpp
@@ -0,0 +1,116 @@
+#include <catch2/catch_all.hpp>
+
+#include "aare/CircularFifo.hpp"
+
+using aare::CircularFifo;
+
+// Only for testing. To make sure we can avoid copy constructor
+// and copy assignment
+
+struct MoveOnlyInt {
+    int value{};
+
+    MoveOnlyInt() = default;
+    MoveOnlyInt(int i) : value(i){};
+    MoveOnlyInt(const MoveOnlyInt &) = delete;
+    MoveOnlyInt &operator=(const MoveOnlyInt &) = delete;
+    MoveOnlyInt(MoveOnlyInt &&other) { std::swap(value, other.value); }
+    MoveOnlyInt &operator=(MoveOnlyInt &&other) {
+        std::swap(value, other.value);
+        return *this;
+    }
+    bool operator==(int other) const { return value == other; }
+};
+
+TEST_CASE("CircularFifo can be default constructed") { CircularFifo<MoveOnlyInt> f; }
+
+TEST_CASE("Newly constructed fifo has the right size") {
+    size_t size = 17;
+    CircularFifo<MoveOnlyInt> f(size);
+    CHECK(f.numFreeSlots() == size);
+    CHECK(f.numFilledSlots() == 0);
+}
+
+TEST_CASE("Can fit size number of objects") {
+    size_t size = 8;
+    size_t numPushedItems = 0;
+    CircularFifo<MoveOnlyInt> f(size);
+    for (size_t i = 0; i < size; ++i) {
+        MoveOnlyInt a;
+        bool popped = f.try_pop_free(a);
+        CHECK(popped);
+        if (popped) {
+            a.value = i;
+            bool pushed = f.try_push_value(std::move(a));
+            CHECK(pushed);
+            if (pushed)
+                numPushedItems++;
+        }
+    }
+    CHECK(f.numFreeSlots() == 0);
+    CHECK(f.numFilledSlots() == size);
+    CHECK(numPushedItems == size);
+}
+
+TEST_CASE("Push move only type") {
+    CircularFifo<MoveOnlyInt> f;
+    f.push_value(5);
+}
+
+TEST_CASE("Push pop") {
+    CircularFifo<MoveOnlyInt> f;
+    f.push_value(MoveOnlyInt(1));
+
+    auto a = f.pop_value();
+    CHECK(a == 1);
+}
+
+TEST_CASE("Pop free and then push") {
+    CircularFifo<MoveOnlyInt> f;
+
+    auto a = f.pop_free();
+    a.value = 5;
+    f.push_value(std::move(a)); // Explicit move since we can't copy
+    auto b = f.pop_value();
+
+    CHECK(a == 0); // Moved from value
+    CHECK(b == 5); // Original value
+}
+
+TEST_CASE("Skip the first value") {
+    CircularFifo<MoveOnlyInt> f;
+
+    for (int i = 0; i != 10; ++i) {
+        auto a = f.pop_free();
+        a.value = i + 1;
+        f.push_value(std::move(a)); // Explicit move since we can't copy
+    }
+
+    auto b = f.pop_value();
+    CHECK(b == 1);
+    f.next();
+    auto c = f.pop_value();
+    CHECK(c == 3);
+}
+
+TEST_CASE("Use in place and move to free") {
+    size_t size = 18;
+    CircularFifo<MoveOnlyInt> f(size);
+
+    //Push 10 values to the fifo
+    for (int i = 0; i != 10; ++i) {
+        auto a = f.pop_free();
+        a.value = i + 1;
+        f.push_value(std::move(a)); // Explicit move since we can't copy
+    }
+
+    auto b = f.frontPtr();
+    CHECK(*b == 1);
+    CHECK(f.numFilledSlots() == 10);
+    CHECK(f.numFreeSlots() == size-10);
+    f.next();
+    auto c = f.frontPtr();
+    CHECK(*c == 2);
+    CHECK(f.numFilledSlots() == 9);
+    CHECK(f.numFreeSlots() == size-9);
+}
diff --git a/core/src/ProducerConsumerQueue.test.cpp b/core/src/ProducerConsumerQueue.test.cpp
new file mode 100644
index 0000000..a89ebad
--- /dev/null
+++ b/core/src/ProducerConsumerQueue.test.cpp
@@ -0,0 +1,45 @@
+#include <catch2/catch_all.hpp>
+#include "aare/ProducerConsumerQueue.hpp"
+
+// using arve::SimpleQueue;
+TEST_CASE("push pop"){
+
+    folly::ProducerConsumerQueue<int> q(5); 
+    int a = 3;
+    int b = 8;
+    CHECK(q.sizeGuess() == 0);
+    CHECK(q.write(a));
+    CHECK(q.sizeGuess() == 1);
+    CHECK(q.write(b));
+    CHECK(q.sizeGuess() == 2);
+    int c = 0;
+
+    CHECK(q.read(c));
+    CHECK(c == 3);
+    CHECK(q.sizeGuess() == 1);
+    CHECK(q.read(c));
+    CHECK(c == 8);
+    CHECK(q.sizeGuess() == 0);
+}
+
+TEST_CASE("Cannot push to a full queue"){
+    folly::ProducerConsumerQueue<int> q(3); 
+    int a = 3;
+    int b = 4;
+    int c = 0;
+    CHECK(q.write(a));
+    CHECK(q.write(b));
+    CHECK_FALSE(q.write(a));
+
+    //values are still ok
+    CHECK(q.read(c));
+    CHECK(c == 3);
+    CHECK(q.read(c));
+    CHECK(c == 4);
+}
+
+TEST_CASE("Cannot pop from an empty queue"){
+    folly::ProducerConsumerQueue<int> q(2);
+    int a=0; 
+    CHECK_FALSE(q.read(a));
+}
\ No newline at end of file