update: remove atomic_ref #21

8sileus · May 14, 2024 · f3a4970 · f3a4970
1 parent 932b361
commit f3a4970
Showing 1 changed file with 11 additions and 19 deletions.
diff --git a/zedio/runtime/multi_thread/queue.hpp b/zedio/runtime/multi_thread/queue.hpp
@@ -102,17 +102,15 @@ class LocalQueue {
     [[nodiscard]]
     auto remaining_slots() -> std::size_t {
         auto [steal, _] = unpack(head_.load(std::memory_order::acquire));
-        std::atomic_ref<uint32_t> atoimc_tail{tail_};
-        auto                      tail = atoimc_tail.load(std::memory_order::acquire);
+        auto tail = tail_.load(std::memory_order::acquire);
         assert(detail::LOCAL_QUEUE_CAPACITY >= static_cast<std::size_t>(tail - steal));
         return detail::LOCAL_QUEUE_CAPACITY - static_cast<std::size_t>(tail - steal);
     }
 
     [[nodiscard]]
     auto size() -> uint32_t {
         auto [_, head] = unpack(head_.load(std::memory_order::acquire));
-        std::atomic_ref<uint32_t> atoimc_tail{tail_};
-        auto                      tail = atoimc_tail.load(std::memory_order::acquire);
+        auto tail = tail_.load(std::memory_order::acquire);
         return tail - head;
     }
 
@@ -132,7 +130,7 @@ class LocalQueue {
         assert(0 < len && len <= capacity());
 
         auto [steal, _] = unpack(head_.load(std::memory_order::acquire));
-        auto tail = tail_;
+        auto tail = tail_.load(std::memory_order::relaxed);
 
         if (tail - steal > static_cast<uint32_t>(capacity() - len)) [[unlikely]] {
             throw std::runtime_error(std::format("push_back overflow! cur size {}, push size {}",
@@ -144,11 +142,9 @@ class LocalQueue {
             std::size_t idx = tail & MASK;
             buffer_[idx] = std::move(task);
             tail += 1;
-            // tail = wrapping_add(tail, 1);
         }
 
-        std::atomic_ref<uint32_t> atomic_tail{tail_};
-        atomic_tail.store(tail, std::memory_order::release);
+        tail_.store(tail, std::memory_order::release);
     }
 
     void push_back_or_overflow(std::coroutine_handle<> task, GlobalQueue &global_queue) {
@@ -157,7 +153,7 @@ class LocalQueue {
         while (true) {
             auto head = head_.load(std::memory_order::acquire);
             auto [steal, real] = unpack(head);
-            tail = tail_;
+            tail = tail_.load(std::memory_order::relaxed);
             if (tail - steal < static_cast<uint32_t>(detail::LOCAL_QUEUE_CAPACITY)) {
                 // There is capacity for the task
                 break;
@@ -175,8 +171,7 @@ class LocalQueue {
         }
         std::size_t idx = static_cast<std::size_t>(tail) & MASK;
         buffer_[idx] = std::move(task);
-        std::atomic_ref atomic_tail{tail_};
-        atomic_tail.store(tail + 1, std::memory_order::release);
+        tail_.store(tail + 1, std::memory_order::release);
     }
 
     [[nodiscard]]
@@ -185,7 +180,7 @@ class LocalQueue {
         std::size_t idx = 0;
         while (true) {
             auto [steal, real] = unpack(head);
-            auto tail = tail_;
+            auto tail = tail_.load(std::memory_order::relaxed);
             if (real == tail) {
                 // Queue is empty
                 return std::nullopt;
@@ -209,7 +204,7 @@ class LocalQueue {
         std::optional<std::coroutine_handle<>> result{std::nullopt};
 
         auto [steal, _] = unpack(dst.head_.load(std::memory_order::acquire));
-        auto dst_tail = dst.tail_;
+        auto dst_tail = dst.tail_.load(std::memory_order::relaxed);
 
         // less than half of local_queue_capacity just return
         if (dst_tail - steal > static_cast<uint32_t>(detail::LOCAL_QUEUE_CAPACITY / 2)) {
@@ -226,8 +221,7 @@ class LocalQueue {
         std::size_t idx = static_cast<std::size_t>(dst_new_tail) & MASK;
         result.emplace(std::move(dst.buffer_[idx]));
         if (n > 0) {
-            std::atomic_ref atomic_dst_tail{dst.tail_};
-            atomic_dst_tail.store(dst_new_tail, std::memory_order::release);
+            dst.tail_.store(dst_new_tail, std::memory_order::release);
         }
         return result;
     }
@@ -240,8 +234,7 @@ class LocalQueue {
         uint32_t n = 0;
         while (true) {
             auto [src_steal, src_real] = unpack(prev_packed);
-            std::atomic_ref<uint32_t> atomic_src_tail{tail_};
-            auto                      src_tail = atomic_src_tail.load(std::memory_order::acquire);
+            auto src_tail = tail_.load(std::memory_order::acquire);
 
             if (src_steal != src_real) {
                 // Other thread is stealing
@@ -338,8 +331,7 @@ class LocalQueue {
 
 private:
     std::atomic<uint64_t> head_{0};
-    uint32_t              tail_{0};
-    // std::atomic<uint32_t> tail_{0};
+    std::atomic<uint32_t> tail_{0};
     std::array<std::coroutine_handle<>, detail::LOCAL_QUEUE_CAPACITY> buffer_;
 };