MemlessPoly: replace async by own threadpool

It is slightly faster, but the main advantage is that there
is no slowdown when running under gdb because it doesn't create
and destroy threads for every frame.

1 files changed, 45 insertions, 1 deletions

diff --git a/src/MemlessPoly.h b/src/MemlessPoly.h
index 4dcd44a..57c0924 100644
--- a/src/MemlessPoly.h
+++ b/src/MemlessPoly.h
@@ -67,7 +67,51 @@ private:
     int internal_process(Buffer* const dataIn, Buffer* dataOut);
     void load_coefficients(const std::string &coefFile);
 
-    unsigned int m_num_threads;
+    struct worker_t {
+        struct input_data_t {
+            bool terminate = false;
+
+            const float *coefs_am = nullptr;
+            const float *coefs_pm = nullptr;
+            const complexf *in = nullptr;
+            size_t start = 0;
+            size_t stop = 0;
+            complexf *out = nullptr;
+        };
+
+        worker_t() {}
+        worker_t(const worker_t& other) = delete;
+        worker_t operator=(const worker_t& other) = delete;
+        worker_t operator=(worker_t&& other) = delete;
+
+        // The move constructor creates a new in_queue and out_queue,
+        // because ThreadsafeQueue is neither copy- nor move-constructible.
+        // Not an issue because creating the workers happens at startup, before
+        // the first work item.
+        worker_t(worker_t&& other) :
+            in_queue(),
+            out_queue(),
+            thread(std::move(other.thread)) {}
+
+        ~worker_t() {
+            if (thread.joinable()) {
+                input_data_t terminate_tag;
+                terminate_tag.terminate = true;
+                in_queue.push(terminate_tag);
+                thread.join();
+            }
+        }
+
+        ThreadsafeQueue<input_data_t> in_queue;
+        ThreadsafeQueue<int> out_queue;
+
+        std::thread thread;
+    };
+
+    std::vector<worker_t> m_workers;
+
+    static void worker_thread(worker_t *workerdata);
+
     std::vector<float> m_coefs_am; // AM/AM coefficients
     std::vector<float> m_coefs_pm; // AM/PM coefficients
     std::string m_coefs_file;