From 008c16e0840b625a96103c0e14082007dcb4e0c2 Mon Sep 17 00:00:00 2001
From: Will <edant.io@proton.me>
Date: Fri, 8 Mar 2024 21:36:37 -0500
Subject: [PATCH] adapter/darwin: atomic sync experiments

---
 .../detail/wtr/watcher/synchronized.hpp       | 23 ++++++-------------
 include/wtr/watcher.hpp                       | 23 ++++++-------------
 2 files changed, 14 insertions(+), 32 deletions(-)

diff --git a/devel/include/detail/wtr/watcher/synchronized.hpp b/devel/include/detail/wtr/watcher/synchronized.hpp
index cfda9157..f3d8ea23 100644
--- a/devel/include/detail/wtr/watcher/synchronized.hpp
+++ b/devel/include/detail/wtr/watcher/synchronized.hpp
@@ -34,18 +34,9 @@ class Synchronized {
     bool exchange_when_current_is,
     bool want_value) -> bool
   {
-#ifdef WTR_ALLOW_NON_SEQUENTIAL_CONSISTENCY
-    constexpr auto relord = std::memory_order_release;
-    constexpr auto acqord = std::memory_order_acquire;
-#else
-    constexpr auto relord = std::memory_order_seq_cst;
-    constexpr auto acqord = std::memory_order_seq_cst;
-#endif
     return current_value.compare_exchange_strong(
       exchange_when_current_is,
-      want_value,
-      acqord,
-      relord);
+      want_value);
   }
 
   inline static auto try_take(std::atomic<bool>& owner_flag) -> bool
@@ -53,14 +44,14 @@ class Synchronized {
     return exchange_when(owner_flag, false, true);
   }
 
-  inline static auto try_leave(std::atomic<bool>& owner_flag) -> bool
+  inline static auto eventually_take(std::atomic<bool>& owner_flag)
   {
-    return exchange_when(owner_flag, true, false);
+    while (! try_take(owner_flag)) { ; }
   }
 
-  inline static auto eventually_take(std::atomic<bool>& owner_flag)
+  inline static auto leave(std::atomic<bool>& owner_flag) -> void
   {
-    while (! try_take(owner_flag)) { std::this_thread::yield(); }
+    owner_flag.store(false);
   }
 
 #else
@@ -70,7 +61,7 @@ class Synchronized {
     return mtx.try_lock();
   }
 
-  inline static auto try_leave(std::mutex& mtx) { mtx.unlock(); }
+  inline static auto leave(std::mutex& mtx) { mtx.unlock(); }
 
   inline static auto eventually_take(std::mutex& mtx) { mtx.lock(); }
 
@@ -92,7 +83,7 @@ class Synchronized {
     return Synchronized{primitive};
   }
 
-  inline ~Synchronized() { try_leave(this->primitive); }
+  inline ~Synchronized() { leave(this->primitive); }
 };
 
 #endif
diff --git a/include/wtr/watcher.hpp b/include/wtr/watcher.hpp
index 591aa387..46f4c0e2 100644
--- a/include/wtr/watcher.hpp
+++ b/include/wtr/watcher.hpp
@@ -502,18 +502,9 @@ class Synchronized {
     bool exchange_when_current_is,
     bool want_value) -> bool
   {
-#ifdef WTR_ALLOW_NON_SEQUENTIAL_CONSISTENCY
-    constexpr auto relord = std::memory_order_release;
-    constexpr auto acqord = std::memory_order_acquire;
-#else
-    constexpr auto relord = std::memory_order_seq_cst;
-    constexpr auto acqord = std::memory_order_seq_cst;
-#endif
     return current_value.compare_exchange_strong(
       exchange_when_current_is,
-      want_value,
-      acqord,
-      relord);
+      want_value);
   }
 
   inline static auto try_take(std::atomic<bool>& owner_flag) -> bool
@@ -521,14 +512,14 @@ class Synchronized {
     return exchange_when(owner_flag, false, true);
   }
 
-  inline static auto try_leave(std::atomic<bool>& owner_flag) -> bool
+  inline static auto eventually_take(std::atomic<bool>& owner_flag)
   {
-    return exchange_when(owner_flag, true, false);
+    while (! try_take(owner_flag)) { ; }
   }
 
-  inline static auto eventually_take(std::atomic<bool>& owner_flag)
+  inline static auto leave(std::atomic<bool>& owner_flag) -> void
   {
-    while (! try_take(owner_flag)) { std::this_thread::yield(); }
+    owner_flag.store(false);
   }
 
 #else
@@ -538,7 +529,7 @@ class Synchronized {
     return mtx.try_lock();
   }
 
-  inline static auto try_leave(std::mutex& mtx) { mtx.unlock(); }
+  inline static auto leave(std::mutex& mtx) { mtx.unlock(); }
 
   inline static auto eventually_take(std::mutex& mtx) { mtx.lock(); }
 
@@ -560,7 +551,7 @@ class Synchronized {
     return Synchronized{primitive};
   }
 
-  inline ~Synchronized() { try_leave(this->primitive); }
+  inline ~Synchronized() { leave(this->primitive); }
 };
 
 #endif