From 1ebf7bb484f7bc64ff3fe392db129bd5c38210e3 Mon Sep 17 00:00:00 2001
From: gibbed <rick@gibbed.us>
Date: Sun, 4 Aug 2019 11:36:31 -0500
Subject: [PATCH] [Kernel] Implement KeTryToAcquireSpinLockAtRaisedIrql. Maybe
 correctly.

---
 src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc b/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc
index fc220404e..217538bda 100644
--- a/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc
+++ b/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc
@@ -922,6 +922,17 @@ void KeAcquireSpinLockAtRaisedIrql(lpdword_t lock_ptr) {
 DECLARE_XBOXKRNL_EXPORT3(KeAcquireSpinLockAtRaisedIrql, kThreading,
                          kImplemented, kBlocking, kHighFrequency);
 
+dword_t KeTryToAcquireSpinLockAtRaisedIrql(lpdword_t lock_ptr) {
+  // Lock.
+  auto lock = reinterpret_cast<uint32_t*>(lock_ptr.host_address());
+  if (!xe::atomic_cas(0, 1, lock)) {
+    return 0;
+  }
+  return 1;
+}
+DECLARE_XBOXKRNL_EXPORT4(KeTryToAcquireSpinLockAtRaisedIrql, kThreading,
+                         kImplemented, kBlocking, kHighFrequency, kSketchy);
+
 void KeReleaseSpinLockFromRaisedIrql(lpdword_t lock_ptr) {
   // Unlock.
   auto lock = reinterpret_cast<uint32_t*>(lock_ptr.host_address());