From 91ca23a23d749a36ebf6d5fb0ed0392edff62dbd Mon Sep 17 00:00:00 2001
From: IYP-Programer-Yeah <hgsilvermann@yahoo.com>
Date: Sun, 31 May 2020 00:17:27 +0430
Subject: [PATCH] Make SCMP and MCSP FIFO and more performant.

---
 .../details/ring-buffer-type-constructor.inl  | 76 +++++++++++++++++++
 ...i-producer-single-consumer-ring-buffer.inl |  2 +-
 ...le-producer-multi-consumer-ring-buffer.inl |  2 +-
 3 files changed, 78 insertions(+), 2 deletions(-)

diff --git a/WaitFreeRingBufferUtilities/Include/details/ring-buffer-type-constructor.inl b/WaitFreeRingBufferUtilities/Include/details/ring-buffer-type-constructor.inl
index d736d57..a720039 100644
--- a/WaitFreeRingBufferUtilities/Include/details/ring-buffer-type-constructor.inl
+++ b/WaitFreeRingBufferUtilities/Include/details/ring-buffer-type-constructor.inl
@@ -188,6 +188,82 @@ struct MultiConsumerTypeTraits
     };
 };
 
+struct MultiProducerForSingleConsumerTypeTraits
+{
+    template <typename BaseType>
+    struct Behavior : BaseType
+    {
+    private:
+        CacheAlignedAndPaddedObject<std::atomic_size_t> end{std::size_t(0)};
+
+    public:
+        using ElementType = typename BaseType::ElementType;
+
+        template <typename... Args>
+        bool push(Args &&... args)
+        {
+            if (BaseType::push_task_count.fetch_sub(1, std::memory_order_acquire) <= std::int64_t(0))
+            {
+                BaseType::push_task_count.fetch_add(1, std::memory_order_relaxed);
+                return false;
+            }
+
+            const std::size_t element_index = end.fetch_add(1, std::memory_order_acquire) & BaseType::COUNT_MASK;
+            auto &element = BaseType::elements[element_index];
+
+            element.value_ptr = new (&element.storage) ElementType(std::forward<Args>(args)...);
+            element.state.store(ElementState::READY_FOR_POP, std::memory_order_release);
+            BaseType::pop_task_count.fetch_add(1, std::memory_order_release);
+            return true;
+        }
+    };
+
+    template <typename BaseType, typename = Private::CountInt64CompatibilityCheck<BaseType::COUNT>>
+    struct SharedState : BaseType
+    {
+    protected:
+        CacheAlignedAndPaddedObject<std::atomic<std::int64_t>> push_task_count{static_cast<std::int64_t>(BaseType::COUNT)};
+    };
+};
+
+struct MultiConsumerForSingleProducerTypeTraits
+{
+    template <typename BaseType>
+    struct Behavior : BaseType
+    {
+    private:
+        CacheAlignedAndPaddedObject<std::atomic_size_t> begin{std::size_t(0)};
+
+    public:
+        using ElementType = typename BaseType::ElementType;
+
+        OptionalType<ElementType> pop()
+        {
+            if (BaseType::pop_task_count.fetch_sub(1, std::memory_order_acquire) <= std::int64_t(0))
+            {
+                BaseType::pop_task_count.fetch_add(1, std::memory_order_relaxed);
+                return OptionalType<ElementType>{};
+            }
+
+            const std::size_t element_index = begin.fetch_add(1, std::memory_order_acquire) & BaseType::COUNT_MASK;
+            auto &element = BaseType::elements[element_index];
+
+            OptionalType<ElementType> result{std::move(*element.value_ptr)};
+            element.value_ptr->~ElementType();
+
+            element.state.store(ElementState::READY_FOR_PUSH, std::memory_order_release);
+            return result;
+        }
+    };
+
+    template <typename BaseType, typename = Private::CountInt64CompatibilityCheck<BaseType::COUNT>>
+    struct SharedState : BaseType
+    {
+    protected:
+        CacheAlignedAndPaddedObject<std::atomic<std::int64_t>> pop_task_count{std::int64_t{0}};
+    };
+};
+
 struct SingleProducerTypeTraits
 {
     template <typename BaseType>
diff --git a/WaitFreeRingBufferUtilities/Include/multi-producer-single-consumer-ring-buffer.inl b/WaitFreeRingBufferUtilities/Include/multi-producer-single-consumer-ring-buffer.inl
index 0f0bb34..15d8e2d 100644
--- a/WaitFreeRingBufferUtilities/Include/multi-producer-single-consumer-ring-buffer.inl
+++ b/WaitFreeRingBufferUtilities/Include/multi-producer-single-consumer-ring-buffer.inl
@@ -13,7 +13,7 @@ namespace WaitFreeRingBufferUtilities
 template <typename T, std::size_t Count>
 struct RingBuffer<T,
                   AccessRequirements::SINGLE_CONSUMER | AccessRequirements::MULTI_PRODUCER,
-                  Count> : Details::RingBufferTypeConstructor<Details::MultiProducerTypeTraits,
+                  Count> : Details::RingBufferTypeConstructor<Details::MultiProducerForSingleConsumerTypeTraits,
                                                               Details::SingleConsumerTypeTraits,
                                                               T, Count>
 {
diff --git a/WaitFreeRingBufferUtilities/Include/single-producer-multi-consumer-ring-buffer.inl b/WaitFreeRingBufferUtilities/Include/single-producer-multi-consumer-ring-buffer.inl
index f70fd46..01192e5 100644
--- a/WaitFreeRingBufferUtilities/Include/single-producer-multi-consumer-ring-buffer.inl
+++ b/WaitFreeRingBufferUtilities/Include/single-producer-multi-consumer-ring-buffer.inl
@@ -14,7 +14,7 @@ template <typename T, std::size_t Count>
 struct RingBuffer<T,
                   AccessRequirements::MULTI_CONSUMER | AccessRequirements::SINGLE_PRODUCER,
                   Count> : Details::RingBufferTypeConstructor<Details::SingleProducerTypeTraits,
-                                                              Details::MultiConsumerTypeTraits,
+                                                              Details::MultiConsumerForSingleProducerTypeTraits,
                                                               T, Count>
 {
 };