1 files changed, 84 insertions, 0 deletions
diff --git a/lib/spdlog/details/mpmc_blocking_q.h b/lib/spdlog/details/mpmc_blocking_q.h
new file mode 100644
index 0000000..d4a8a41
--- /dev/null
+++ b/lib/spdlog/details/mpmc_blocking_q.h
@@ -0,0 +1,84 @@
+#pragma once
+
+//
+// Copyright(c) 2018 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+// async log helper :
+// multi producer-multi consumer blocking queue
+// enqueue(..) - will block until room found to put the new message
+// enqueue_nowait(..) - will return immediatly with false if no room left in the queue
+// dequeue_for(..) - will block until the queue is not empty or timeout passed
+
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+
+namespace spdlog {
+namespace details {
+
+template<typename T>
+class mpmc_bounded_queue
+{
+public:
+    using item_type = T;
+    explicit mpmc_bounded_queue(size_t max_items)
+        : max_items_(max_items)
+    {
+    }
+
+    // try to enqueue and block if no room left
+    void enqueue(T &&item)
+    {
+        {
+            std::unique_lock<std::mutex> lock(queue_mutex_);
+            pop_cv_.wait(lock, [this] { return this->q_.size() < this->max_items_; });
+            q_.push(std::move(item));
+        }
+        push_cv_.notify_one();
+    }
+
+    // try to enqueue and return immdeialty false if no room left
+    bool enqueue_nowait(T &&item)
+    {
+        {
+            std::unique_lock<std::mutex> lock(queue_mutex_);
+            if (q_.size() == this->max_items_)
+            {
+                return false;
+            }
+            q_.push(std::forward<T>(item));
+        }
+        push_cv_.notify_one();
+        return true;
+    }
+
+    // try to dequeue item. if no item found. wait upto timeout and try again
+    // Return true, if succeeded dequeue item, false otherwise
+    bool dequeue_for(T &popped_item, std::chrono::milliseconds wait_duration)
+    {
+        {
+            std::unique_lock<std::mutex> lock(queue_mutex_);
+            if (!push_cv_.wait_for(lock, wait_duration, [this] { return this->q_.size() > 0; }))
+            {
+                return false;
+            }
+
+            popped_item = std::move(q_.front());
+            q_.pop();
+        }
+        pop_cv_.notify_one();
+        return true;
+    }
+
+private:
+    size_t max_items_;
+    std::mutex queue_mutex_;
+    std::condition_variable push_cv_;
+    std::condition_variable pop_cv_;
+
+    std::queue<T> q_;
+};
+} // namespace details
+} // namespace spdlog