From 3162a6435cef7211a7d4062ba2e76951e1bd9063 Mon Sep 17 00:00:00 2001
From: gibbed <rick@gibbed.us>
Date: Fri, 7 Jan 2022 09:19:15 -0600
Subject: [PATCH] [xboxkrnl] Implement ExTryToAcquireRWLExclusive.

[xboxkrnl] Implement ExTryToAcquireReadWriteLockExclusive.
---
 .../kernel/xboxkrnl/xboxkrnl_threading.cc      | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc b/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc
index 62c445635..163118cfc 100644
--- a/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc
+++ b/src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc
@@ -1199,6 +1199,24 @@ void ExAcquireReadWriteLockExclusive(pointer_t<X_ERWLOCK> lock_ptr) {
 DECLARE_XBOXKRNL_EXPORT2(ExAcquireReadWriteLockExclusive, kThreading,
                          kImplemented, kBlocking);
 
+dword_result_t ExTryToAcquireReadWriteLockExclusive(
+    pointer_t<X_ERWLOCK> lock_ptr) {
+  auto old_irql = xeKeKfAcquireSpinLock(&lock_ptr->spin_lock);
+
+  uint32_t result;
+  if (lock_ptr->lock_count < 0) {
+    lock_ptr->lock_count = 0;
+    result = 1;
+  } else {
+    result = 0;
+  }
+
+  xeKeKfReleaseSpinLock(&lock_ptr->spin_lock, old_irql);
+  return result;
+}
+DECLARE_XBOXKRNL_EXPORT1(ExTryToAcquireReadWriteLockExclusive, kThreading,
+                         kImplemented);
+
 void ExReleaseReadWriteLock(pointer_t<X_ERWLOCK> lock_ptr) {
   auto old_irql = xeKeKfAcquireSpinLock(&lock_ptr->spin_lock);