Merge pull request #1233 from trapexit/atomic

Use relaxed memory order for atomic counters
trapexit · Aug 21, 2023 · 51b65cd · 51b65cd
2 parents b6d3c34 + 0ed03a1
commit 51b65cd
Show file tree

Hide file tree

Showing 4 changed files with 12 additions and 135 deletions.
diff --git a/libfuse/lib/bounded_thread_pool.hpp b/libfuse/lib/bounded_thread_pool.hpp
@@ -85,7 +85,7 @@ class BoundedThreadPool
   void
   enqueue_work(F&& f_)
   {
-    auto i = _index++;
+    auto i = _index.fetch_add(1,std::memory_order_relaxed);
 
     for(std::size_t n = 0; n < (_count * K); ++n)
       {
@@ -104,10 +104,11 @@ class BoundedThreadPool
     using TaskReturnType = typename std::result_of<F()>::type;
     using Promise        = std::promise<TaskReturnType>;
 
-    auto i       = _index++;
+    auto i       = _index.fetch_add(1,std::memory_order_relaxed);
     auto promise = std::make_shared<Promise>();
     auto future  = promise->get_future();
-    auto work    = [=]() {
+    auto work    = [=]()
+    {
       auto rv = f_();
       promise->set_value(rv);
     };

diff --git a/libfuse/lib/fuse_msgbuf.cpp b/libfuse/lib/fuse_msgbuf.cpp
@@ -115,7 +115,7 @@ _msgbuf_alloc(msgbuf_setup_func_t setup_func_)
       if(msgbuf == NULL)
         return NULL;
 
-      g_MSGBUF_ALLOC_COUNT++;
+      g_MSGBUF_ALLOC_COUNT.fetch_add(1,std::memory_order_relaxed);
     }
   else
     {
@@ -160,7 +160,7 @@ msgbuf_free(fuse_msgbuf_t *msgbuf_)
   if(msgbuf_->size != (g_BUFSIZE - g_PAGESIZE))
     {
       msgbuf_destroy(msgbuf_);
-      g_MSGBUF_ALLOC_COUNT--;
+      g_MSGBUF_ALLOC_COUNT.fetch_sub(1,std::memory_order_relaxed);
       return;
     }
 
@@ -206,7 +206,7 @@ msgbuf_gc_10percent()
   for(auto msgbuf : togc)
     {
       msgbuf_destroy(msgbuf);
-      g_MSGBUF_ALLOC_COUNT--;
+      g_MSGBUF_ALLOC_COUNT.fetch_sub(1,std::memory_order_relaxed);
     }
 }
 
@@ -223,6 +223,6 @@ msgbuf_gc()
   for(auto msgbuf: oldstack)
     {
       msgbuf_destroy(msgbuf);
-      g_MSGBUF_ALLOC_COUNT--;
+      g_MSGBUF_ALLOC_COUNT.fetch_sub(1,std::memory_order_relaxed);
     }
 }
diff --git a/libfuse/lib/thread_pool.hpp b/libfuse/lib/thread_pool.hpp
diff --git a/src/unbounded_thread_pool.hpp b/src/unbounded_thread_pool.hpp
@@ -72,7 +72,7 @@ class ThreadPool
   void
   enqueue_work(F&& f_)
   {
-    auto i = _index++;
+    auto i = _index.fetch_add(1,std::memory_order_relaxed);
 
     for(std::size_t n = 0; n < (_count * K); ++n)
       {
@@ -91,10 +91,11 @@ class ThreadPool
     using TaskReturnType = typename std::result_of<F()>::type;
     using Promise        = std::promise<TaskReturnType>;
 
-    auto i       = _index++;
+    auto i       = _index.fetch_add(1,std::memory_order_relaxed);
     auto promise = std::make_shared<Promise>();
     auto future  = promise->get_future();
-    auto work    = [=]() {
+    auto work    = [=]()
+    {
       auto rv = f_();
       promise->set_value(rv);
     };