From 56681889458e2c8dec6dce10fe0d5df7cda44059 Mon Sep 17 00:00:00 2001
From: Jamie Reece Wilson <me@reece.sx>
Date: Sun, 31 Mar 2024 09:26:56 +0100
Subject: [PATCH] [*] Harden IO handle interface

---
 Source/IO/AuIOHandle.cpp | 18 ++++++++++++++-
 Source/IO/AuIOHandle.hpp | 48 +++++++++++++++++++++++++++++++---------
 2 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/Source/IO/AuIOHandle.cpp b/Source/IO/AuIOHandle.cpp
index f9580bdc..8c88aea4 100644
--- a/Source/IO/AuIOHandle.cpp
+++ b/Source/IO/AuIOHandle.cpp
@@ -61,6 +61,8 @@ namespace Aurora::IO
     {
         SysCheckArgNotNull(pHandle, false);
 
+        AU_LOCK_GUARD(this);
+
         auto pSrc = AuStaticCast<AFileHandle>(pHandle);
         auto pDest = this;
 
@@ -79,6 +81,8 @@ namespace Aurora::IO
 
     bool AFileHandle::InitFromCopy(AuUInt64 uOSHandle)
     {
+        AU_LOCK_GUARD(this);
+
         if (this->IsValid())
         {
             return false;
@@ -99,6 +103,8 @@ namespace Aurora::IO
 
     bool AFileHandle::InitFromMove(AuUInt64 uOSHandle)
     {
+        AU_LOCK_GUARD(this);
+
         if (this->IsValid())
         {
             return false;
@@ -113,6 +119,8 @@ namespace Aurora::IO
     bool AFileHandle::InitFromPair(AuOptional<AuUInt64> optOSReadHandle,
                                    AuOptional<AuUInt64> optOSWriteHandle)
     {
+        AU_LOCK_GUARD(this);
+
         if (this->IsValid())
         {
             return false;
@@ -152,6 +160,8 @@ namespace Aurora::IO
     bool AFileHandle::InitFromPairMove(AuOptional<AuUInt64> uOSReadHandle,
         AuOptional<AuUInt64> uOSWriteHandle)
     {
+        AU_LOCK_GUARD(this);
+
         if (this->IsValid())
         {
             return false;
@@ -166,6 +176,8 @@ namespace Aurora::IO
 
     bool AFileHandle::InitFromStreamEnum(EStandardStream eStream)
     {
+        AU_LOCK_GUARD(this);
+
         switch (eStream)
         {
         case EStandardStream::eInputStream:
@@ -349,6 +361,8 @@ namespace Aurora::IO
 
     bool AFileHandle::InitFromSharing(const AuString &handle)
     {
+        AU_LOCK_GUARD(this);
+
         if (this->uOSReadHandle ||
             this->uOSWriteHandle)
         {
@@ -392,7 +406,9 @@ namespace Aurora::IO
     }
 
     AuString AFileHandle::SharingGetString()
-    { 
+    {
+        AU_LOCK_GUARD(this);
+
         AuString handle;
 
         if (this->pIPCString)
diff --git a/Source/IO/AuIOHandle.hpp b/Source/IO/AuIOHandle.hpp
index 40a73e21..c92e6402 100644
--- a/Source/IO/AuIOHandle.hpp
+++ b/Source/IO/AuIOHandle.hpp
@@ -88,17 +88,43 @@ namespace Aurora::IO
 
         bool ShouldClone();
 
-        AuOptional<AuUInt64> uOSWriteHandle;
-        AuOptional<AuUInt64> uOSReadHandle;
-        AuSPtr<IIOHandle> pThat;
-        AuString path;
-        IPC::IPCPipeImpl *pIPCPipe {};
-        mutable AuOptional<bool> optIsFile;
-        mutable AuOptional<bool> optIsPipe;
-        mutable AuOptional<bool> optIsTTY;
-        mutable AuSPtr<AuString> pIPCString;
-        AuUInt uThreadId {};
-        bool bIsAsync {}, bFlushOnClose {}, bShouldWriteEoS {}, bDirectIO {};
+        std::shared_ptr<IIOHandle> pThat;
+        AuString                   path;
+        IPC::IPCPipeImpl *         pIPCPipe { };
+        mutable AuSPtr<AuString>   pIPCString;
+        AuUInt                     uThreadId { };
+        AuOptional<AuUInt64>       uOSWriteHandle;
+        AuOptional<AuUInt64>       uOSReadHandle;
+        mutable AuOptional<bool>   optIsFile;
+        mutable AuOptional<bool>   optIsPipe;
+        mutable AuOptional<bool>   optIsTTY;
+        AuUInt8                    bShouldWriteEoS : 1 { 0 };
+        AuUInt8                    bFlushOnClose   : 1 { 0 };
+        AuUInt8                    bDirectIO       : 1 { 0 };
+        AuUInt8                    bIsAsync        : 1 { 0 };
+        AuAUInt32                  uLock               { 0 };
+
+        inline void Lock()
+        {
+            if (!AuAtomicTestAndSet(&this->uLock, 0))
+            {
+                return;
+            }
+
+            {
+                AuUInt32 uOld {};
+                while ((uOld = AuAtomicCompareExchange(&this->uLock, 1u, 0u)) != 0u)
+                {
+                    AuThreading::WaitOnAddress((const void *)&this->uLock, &uOld, 4, 0, true);
+                }
+            }
+        }
+
+        inline void Unlock()
+        {
+            AuAtomicClearU8Lock(&this->uLock);
+            AuThreading::WakeOnAddress((const void *)&this->uLock);
+        }
 
     protected:
     // Implement me: