From 294df85c1d892fd2c4291310cf58aad5bf3a4e42 Mon Sep 17 00:00:00 2001
From: Coldwings <coldwings@me.com>
Date: Wed, 31 Jan 2024 15:40:23 +0800
Subject: [PATCH] Improve heave load performance in `RingChannel`

Signed-off-by: Coldwings <coldwings@me.com>
---
 common/lockfree_queue.h    | 19 +++++++++++++------
 thread/test/CMakeLists.txt |  4 ++++
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/common/lockfree_queue.h b/common/lockfree_queue.h
index ea288396..5713d6fa 100644
--- a/common/lockfree_queue.h
+++ b/common/lockfree_queue.h
@@ -568,7 +568,7 @@ class RingChannel : public QueueType {
      * parameter DEFAULT_BUSY_YIELD_TIMEOUT. Ring Channel will try busy yield
      * in `busy_yield_timeout` usecs.
      */
-    RingChannel(uint64_t busy_yield_turn = 64,
+    RingChannel(uint64_t busy_yield_turn = -1UL,
                 uint64_t busy_yield_timeout = 1024)
         : m_busy_yield_turn(busy_yield_turn),
           m_busy_yield_timeout(busy_yield_timeout) {}
@@ -576,22 +576,29 @@ class RingChannel : public QueueType {
     template <typename Pause = ThreadPause>
     void send(const T& x) {
         while (!push(x)) {
-            if (!full()) Pause::pause();
+            Pause::pause();
         }
         queue_sem.signal(idler.load(std::memory_order_acquire));
     }
     T recv() {
         T x;
-        Timeout yield_timeout(m_busy_yield_timeout);
-        int yield_turn = m_busy_yield_turn;
+        if (pop(x)) return x;
+        // yield once if failed, so photon::now will be update
+        photon::thread_yield();
         idler.fetch_add(1, std::memory_order_acq_rel);
         DEFER(idler.fetch_sub(1, std::memory_order_acq_rel));
+        Timeout yield_timeout(m_busy_yield_timeout);
+        uint64_t yield_turn = m_busy_yield_turn;
         while (!pop(x)) {
-            if (yield_turn > 0 && photon::now < yield_timeout.expiration()) {
+            if (yield_turn > 0 && !yield_timeout.expired()) {
                 yield_turn--;
                 photon::thread_yield();
             } else {
-                queue_sem.wait(1);
+                // wait for 100ms
+                queue_sem.wait(1, 100UL * 1000);
+                // reset yield mark and set into busy wait
+                yield_turn = m_busy_yield_turn;
+                yield_timeout.timeout(m_busy_yield_timeout);
             }
         }
         return x;
diff --git a/thread/test/CMakeLists.txt b/thread/test/CMakeLists.txt
index 9311430e..a8cec41f 100644
--- a/thread/test/CMakeLists.txt
+++ b/thread/test/CMakeLists.txt
@@ -4,6 +4,10 @@ add_executable(perf_usleepdefer_semaphore perf_usleepdefer_semaphore.cpp)
 target_link_libraries(perf_usleepdefer_semaphore PRIVATE photon_shared)
 add_test(NAME perf_usleepdefer_semaphore COMMAND $<TARGET_FILE:perf_usleepdefer_semaphore>)
 
+add_executable(perf_workpool perf_workpool.cpp)
+target_link_libraries(perf_workpool PRIVATE photon_shared)
+add_test(NAME perf_workpool COMMAND $<TARGET_FILE:perf_workpool>)
+
 add_executable(test-thread test.cpp x.cpp)
 target_link_libraries(test-thread PRIVATE photon_static)
 add_test(NAME test-thread COMMAND $<TARGET_FILE:test-thread>)