Change max batch to one

src/http_handler.hpp

@@ -103,10 +103,12 @@ struct HttpHandler : ConnectionHandler {
     });
     stage0Thread = std::thread{[this]() {
       pthread_setname_np(pthread_self(), "stage-0");
+      int nulls = 0;
       for (;;) {
-        auto guard = pipeline.acquire<0, 0>();
+        auto guard = pipeline.acquire<0, 0>(1);
         for (auto &c : guard.batch) {
-          if (!c) {
+          nulls += !c;
+          if (nulls == 2) {
             return;
           }
           for (volatile int i = 0; i < loopIterations; i = i + 1)

src/loop_iterations.h

@@ -1,3 +1,3 @@
 #pragma once
 
-constexpr int loopIterations = 1550;
+constexpr int loopIterations = 1725;

src/thread_pipeline.hpp

@@ -11,6 +11,10 @@
 #include <utility>
 #include <vector>
 
+#if defined(__x86_64__) || defined(_M_X64)
+#include <immintrin.h>
+#endif
+
 // Wait strategies for controlling thread blocking behavior when no work is
 // available
 enum class WaitStrategy {
@@ -151,6 +155,9 @@ uint32_t calculate_safe_len(
                   if (push != thread.local_pops) {
                     goto dont_wait;
                   }
+#if defined(__x86_64__) || defined(_M_X64)
+                  _mm_pause();
+#endif
                 }
                 pushes.wait(push, std::memory_order_relaxed);
               dont_wait:;