From 56e2da569ebd3781cb4f42fa650377f14c461547 Mon Sep 17 00:00:00 2001
From: Huiba Li <huiba.lhb@alibaba-inc.com>
Date: Fri, 14 Jun 2024 14:34:19 +0800
Subject: [PATCH] Manual pr 0.6 0.7 (#509)

* FIX: lockfree MPMC queue should not fail to pop/push when queue is not empty/full (#504)

* FIX: lockfree MPMC queue should not fail to pop/push when queue is not empty/full

Signed-off-by: Coldwings <coldwings@me.com>

* Old CI image not able to access repo, change to preset image

Signed-off-by: Coldwings <coldwings@me.com>
---
 .github/workflows/ci.linux.x86-64.yml      | 10 ++++----
 common/lockfree_queue.h                    | 28 +++++++---------------
 examples/sync-primitive/sync-primitive.cpp |  2 +-
 3 files changed, 14 insertions(+), 26 deletions(-)

diff --git a/.github/workflows/ci.linux.x86-64.yml b/.github/workflows/ci.linux.x86-64.yml
index 453dff50..5adc2347 100644
--- a/.github/workflows/ci.linux.x86-64.yml
+++ b/.github/workflows/ci.linux.x86-64.yml
@@ -45,7 +45,7 @@ jobs:
     runs-on: ubuntu-latest
     container:
       image: ghcr.io/coldwings/photon-ut-base:latest
-      options: --cpus 4
+      options: --cpus 4 --privileged
     steps:
       - uses: szenius/set-timezone@v1.2
         with:
@@ -86,7 +86,7 @@ jobs:
     runs-on: ubuntu-latest
     container:
       image: ghcr.io/coldwings/photon-ut-base:latest
-      options: --cpus 4
+      options: --cpus 4 --privileged
     steps:
       - uses: szenius/set-timezone@v1.2
         with:
@@ -127,7 +127,7 @@ jobs:
     runs-on: ubuntu-latest
     container:
       image: ghcr.io/coldwings/photon-ut-base:latest
-      options: --cpus 4
+      options: --cpus 4 --privileged
     steps:
       - uses: szenius/set-timezone@v1.2
         with:
@@ -168,7 +168,7 @@ jobs:
     runs-on: ubuntu-latest
     container:
       image: ghcr.io/coldwings/photon-ut-base:latest
-      options: --cpus 4
+      options: --cpus 4 --privileged
     steps:
       - uses: szenius/set-timezone@v1.2
         with:
@@ -209,7 +209,7 @@ jobs:
     runs-on: ubuntu-latest
     container:
       image: ghcr.io/coldwings/photon-ut-base:latest
-      options: --cpus 4
+      options: --cpus 4 --privileged
     steps:
       - uses: szenius/set-timezone@v1.2
         with:
diff --git a/common/lockfree_queue.h b/common/lockfree_queue.h
index 2d91d123..62f917b0 100644
--- a/common/lockfree_queue.h
+++ b/common/lockfree_queue.h
@@ -181,7 +181,7 @@ class LockfreeMPMCRingQueue : public LockfreeRingQueueBase<T, N> {
     using Base::empty;
     using Base::full;
 
-    bool push_weak(const T& x) {
+    bool push(const T& x) {
         auto t = tail.load(std::memory_order_acquire);
         for (;;) {
             auto& slot = slots[idx(t)];
@@ -194,15 +194,16 @@ class LockfreeMPMCRingQueue : public LockfreeRingQueueBase<T, N> {
                 }
             } else {
                 auto const prevTail = t;
+                auto h = head.load(std::memory_order_acquire);
                 t = tail.load(std::memory_order_acquire);
-                if (t == prevTail) {
+                if (t == prevTail && Base::check_full(h, t)) {
                     return false;
                 }
             }
         }
     }
 
-    bool pop_weak(T& x) {
+    bool pop(T& x) {
         auto h = head.load(std::memory_order_acquire);
         for (;;) {
             auto& slot = slots[idx(h)];
@@ -215,28 +216,15 @@ class LockfreeMPMCRingQueue : public LockfreeRingQueueBase<T, N> {
                 }
             } else {
                 auto const prevHead = h;
+                auto t = tail.load(std::memory_order_acquire);
                 h = head.load(std::memory_order_acquire);
-                if (h == prevHead) {
+                if (h == prevHead && Base::check_empty(h, t)) {
                     return false;
                 }
             }
         }
     }
 
-    bool push(const T& x) {
-        do {
-            if (push_weak(x)) return true;
-        } while (!full());
-        return false;
-    }
-
-    bool pop(T& x) {
-        do {
-            if (pop_weak(x)) return true;
-        } while (!empty());
-        return false;
-    }
-
     template <typename Pause = ThreadPause>
     void send(const T& x) {
         static_assert(std::is_base_of<PauseBase, Pause>::value,
@@ -538,8 +526,8 @@ namespace common {
  * and load balancing.
  * Watch out that `recv` should run in photon environment (because it has to)
  * use photon semaphore to be notified that new item has sended. `send` could
- * running in photon or std::thread environment (needs to set template `Pause` as
- * `ThreadPause`).
+ * running in photon or std::thread environment (needs to set template `Pause`
+ * as `ThreadPause`).
  *
  * @tparam QueueType shoulde be one of LockfreeMPMCRingQueue,
  * LockfreeBatchMPMCRingQueue, or LockfreeSPSCRingQueue, with their own template
diff --git a/examples/sync-primitive/sync-primitive.cpp b/examples/sync-primitive/sync-primitive.cpp
index 173e8ea4..131493b5 100644
--- a/examples/sync-primitive/sync-primitive.cpp
+++ b/examples/sync-primitive/sync-primitive.cpp
@@ -109,7 +109,7 @@ int main() {
             while (true) {
                 func_1us();
                 Message* m;
-                bool ok = ring.pop_weak(m);
+                bool ok = ring.pop(m);
                 if (!ok)
                     continue;
                 m->start = std::chrono::steady_clock::now();