From 346a9f3bded304cf1a171816bc7713edc4d1a49c Mon Sep 17 00:00:00 2001
From: J Reece Wilson <me@reece.sx>
Date: Sat, 26 Aug 2023 15:53:13 +0100
Subject: [PATCH] [*] More aggressively wake up reorder prone (unlikely)
 condvars under broadcast (unlikely)

---
 .../Threading/Waitables/FutexCondWaitable.hpp | 19 +++++++++----------
 Source/Threading/Primitives/AuConditionEx.cpp | 19 +++++++++----------
 .../Primitives/AuConditionVariable.Linux.cpp  | 19 +++++++++----------
 3 files changed, 27 insertions(+), 30 deletions(-)

diff --git a/Include/Aurora/Threading/Waitables/FutexCondWaitable.hpp b/Include/Aurora/Threading/Waitables/FutexCondWaitable.hpp
index abd6b67f..cc9b5e47 100644
--- a/Include/Aurora/Threading/Waitables/FutexCondWaitable.hpp
+++ b/Include/Aurora/Threading/Waitables/FutexCondWaitable.hpp
@@ -124,22 +124,21 @@ namespace Aurora::Threading::Waitables
             AuUInt32 uWaitCount {};
             AuUInt32 uWaiters {};
 
-            uWaiters = AuAtomicLoad(&this->uAtomicSleeping);
-            if (uWaiters > 0)
+            while (uWaiters = AuAtomicLoad(&this->uAtomicSleeping))
             {
                 AuAtomicAdd(&this->uAtomicState, uWaiters);
                 WakeNOnAddress((const void *)&this->uAtomicState, uWaiters);
                 uWaitCount = uWaiters;
-            }
 
-            while (uWaiters &&
-                   AuAtomicCompareExchange(&this->uAtomicSleeping, uWaiters - uWaitCount, uWaiters) != uWaiters)
-            {
-                uWaiters = this->uAtomicSleeping;
-
-                if (uWaiters == 0)
+                while (uWaiters &&
+                       AuAtomicCompareExchange(&this->uAtomicSleeping, uWaiters - uWaitCount, uWaiters) != uWaiters)
                 {
-                    return;
+                    uWaiters = this->uAtomicSleeping;
+
+                    if (uWaiters <= uWaitCount)
+                    {
+                        uWaitCount = uWaiters;
+                    }
                 }
             }
         }
diff --git a/Source/Threading/Primitives/AuConditionEx.cpp b/Source/Threading/Primitives/AuConditionEx.cpp
index 8cff8529..3cad8bb3 100644
--- a/Source/Threading/Primitives/AuConditionEx.cpp
+++ b/Source/Threading/Primitives/AuConditionEx.cpp
@@ -141,21 +141,20 @@ namespace Aurora::Threading::Primitives
         AuUInt32 uWaitCount {};
         AuUInt32 uWaiters {};
 
-        uWaiters = AuAtomicLoad(&this->uWaiters_);
-        if (uWaiters > 0)
+        while (uWaiters = AuAtomicLoad(&this->uWaiters_))
         {
             this->s_.Unlock(uWaiters);
             uWaitCount = uWaiters;
-        }
 
-        while (uWaiters &&
-               AuAtomicCompareExchange(&this->uWaiters_, uWaiters - uWaitCount, uWaiters) != uWaiters)
-        {
-            uWaiters = this->uWaiters_;
-
-            if (uWaiters <= uWaitCount)
+            while (uWaiters &&
+                   AuAtomicCompareExchange(&this->uWaiters_, uWaiters - uWaitCount, uWaiters) != uWaiters)
             {
-                uWaitCount = uWaiters;
+                uWaiters = this->uWaiters_;
+
+                if (uWaiters <= uWaitCount)
+                {
+                    uWaitCount = uWaiters;
+                }
             }
         }
     }
diff --git a/Source/Threading/Primitives/AuConditionVariable.Linux.cpp b/Source/Threading/Primitives/AuConditionVariable.Linux.cpp
index 5e4e5da9..21d27426 100644
--- a/Source/Threading/Primitives/AuConditionVariable.Linux.cpp
+++ b/Source/Threading/Primitives/AuConditionVariable.Linux.cpp
@@ -163,22 +163,21 @@ namespace Aurora::Threading::Primitives
         AuUInt32 uWaitCount {};
         AuUInt32 uWaiters {};
 
-        uWaiters = AuAtomicLoad(&this->uSleeping_);
-        if (uWaiters > 0)
+        while (uWaiters = AuAtomicLoad(&this->uSleeping_))
         {
             AuAtomicAdd(&this->uState_, uWaiters);
             futex_wake(&this->uState_, uWaiters);
             uWaitCount = uWaiters;
-        }
 
-        while (uWaiters &&
-               AuAtomicCompareExchange(&this->uSleeping_, uWaiters - uWaitCount, uWaiters) != uWaiters)
-        {
-            uWaiters = this->uSleeping_;
-
-            if (uWaiters <= uWaitCount)
+            while (uWaiters &&
+                   AuAtomicCompareExchange(&this->uSleeping_, uWaiters - uWaitCount, uWaiters) != uWaiters)
             {
-                uWaitCount = uWaiters;
+                uWaiters = AuAtomicLoad(&this->uSleeping_);
+
+                if (uWaiters <= uWaitCount)
+                {
+                    uWaitCount = uWaiters;
+                }
             }
         }
     }