From 429ff94dc55b4189bebcf1b0e6b5e8034d45095d Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Mon, 6 Jan 2025 18:56:58 +0000
Subject: [PATCH] Windows: Only deinit the thread CRT when destroying the
 current thread

The thread termination callback can be called for other threads in the
process, not just the current one, in which case we cannot call DeinitCRT.
Deinitializing the CRT of another thread would be awkward so just skip that
and accept the small leak for now.
---
 Source/Windows/ARM64EC/Module.cpp | 18 ++++++++++--------
 Source/Windows/WOW64/Module.cpp   | 16 +++++++++-------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/Source/Windows/ARM64EC/Module.cpp b/Source/Windows/ARM64EC/Module.cpp
index a24963412..523b5bcae 100644
--- a/Source/Windows/ARM64EC/Module.cpp
+++ b/Source/Windows/ARM64EC/Module.cpp
@@ -816,20 +816,22 @@ NTSTATUS ThreadTerm(HANDLE Thread, LONG ExitCode) {
   auto* OldThreadState = CPUArea.ThreadState();
   CPUArea.ThreadState() = nullptr;
 
-  {
-    THREAD_BASIC_INFORMATION Info;
-    if (NTSTATUS Err = NtQueryInformationThread(Thread, ThreadBasicInformation, &Info, sizeof(Info), nullptr); Err) {
-      return Err;
-    }
+  THREAD_BASIC_INFORMATION Info;
+  if (NTSTATUS Err = NtQueryInformationThread(Thread, ThreadBasicInformation, &Info, sizeof(Info), nullptr); Err) {
+    return Err;
+  }
 
-    const auto ThreadTID = reinterpret_cast<uint64_t>(Info.ClientId.UniqueThread);
+  const auto ThreadTID = reinterpret_cast<uint64_t>(Info.ClientId.UniqueThread);
+  {
     std::scoped_lock Lock(ThreadCreationMutex);
     Threads.erase(ThreadTID);
   }
 
   CTX->DestroyThread(OldThreadState);
-  ::VirtualFree(reinterpret_cast<void*>(GetCPUArea().EmulatorStackLimit()), 0, MEM_RELEASE);
-  FEX::Windows::DeinitCRTThread();
+  ::VirtualFree(reinterpret_cast<void*>(CPUArea.EmulatorStackLimit()), 0, MEM_RELEASE);
+  if (ThreadTID == GetCurrentThreadId()) {
+    FEX::Windows::DeinitCRTThread();
+  }
   return STATUS_SUCCESS;
 }
 
diff --git a/Source/Windows/WOW64/Module.cpp b/Source/Windows/WOW64/Module.cpp
index ebf5f01b7..df56d2bb0 100644
--- a/Source/Windows/WOW64/Module.cpp
+++ b/Source/Windows/WOW64/Module.cpp
@@ -517,19 +517,21 @@ void BTCpuThreadTerm(HANDLE Thread, LONG ExitCode) {
     return;
   }
 
-  {
-    THREAD_BASIC_INFORMATION Info;
-    if (NTSTATUS Err = NtQueryInformationThread(Thread, ThreadBasicInformation, &Info, sizeof(Info), nullptr); Err) {
-      return;
-    }
+  THREAD_BASIC_INFORMATION Info;
+  if (NTSTATUS Err = NtQueryInformationThread(Thread, ThreadBasicInformation, &Info, sizeof(Info), nullptr); Err) {
+    return;
+  }
 
-    const auto ThreadTID = reinterpret_cast<uint64_t>(Info.ClientId.UniqueThread);
+  const auto ThreadTID = reinterpret_cast<uint64_t>(Info.ClientId.UniqueThread);
+  {
     std::scoped_lock Lock(ThreadCreationMutex);
     Threads.erase(ThreadTID);
   }
 
   CTX->DestroyThread(TLS.ThreadState());
-  FEX::Windows::DeinitCRTThread();
+  if (ThreadTID == GetCurrentThreadId()) {
+    FEX::Windows::DeinitCRTThread();
+  }
 }
 
 void* BTCpuGetBopCode() {