Added GC critical sections

IPA.Loader/Utilities/CriticalSection.cs

@@ -52,6 +52,14 @@ namespace IPA.Utilities
 
         private static volatile bool exitRecieved = false;
 
+        /// <summary>
+        /// Enters a critical execution section. Does not nest.
+        /// </summary>
+        /// <note>
+        /// During a critical execution section, the program must execute until the end of the section before
+        /// exiting. If an exit signal is recieved during the section, it will be canceled, and the process
+        /// will terminate at the end of the section.
+        /// </note>
         public static void EnterExecuteSection()
         {
             ResetExitHandlers();
@@ -60,6 +68,14 @@ namespace IPA.Utilities
             _handler = sig => exitRecieved = true;
         }
 
+        /// <summary>
+        /// Exits a critical execution section. Does not nest.
+        /// </summary>
+        /// <note>
+        /// During a critical execution section, the program must execute until the end of the section before
+        /// exiting. If an exit signal is recieved during the section, it will be canceled, and the process
+        /// will terminate at the end of the section.
+        /// </note>
         public static void ExitExecuteSection()
         {
             _handler = null;
@@ -70,5 +86,44 @@ namespace IPA.Utilities
 
         #endregion
 
+        #region GC section
+
+        // i wish i could reference GC_enable and GC_disable directly
+        [DllImport("mono-2.0-bdwgc")]
+        private static extern void mono_unity_gc_enable();
+        [DllImport("mono-2.0-bdwgc")]
+        private static extern void mono_unity_gc_disable();
+
+        /// <summary>
+        /// Enters a GC critical section. Each call to this must be paired with a call to <see cref="ExitGCSection"/>.
+        /// </summary>
+        /// <note>
+        /// During a GC critical section, no GCs will occur. 
+        /// 
+        /// This may throw an <see cref="EntryPointNotFoundException"/> if the build of Mono the game is running on does
+        /// not have `mono_unity_gc_disable` exported. Use with caution.
+        /// </note>
+        public static void EnterGCSection()
+        {
+            mono_unity_gc_disable();
+        }
+
+
+        /// <summary>
+        /// Exits a GC critical section. Each call to this must have a preceding call to <see cref="EnterGCSection"/>.
+        /// </summary>
+        /// <note>
+        /// During a GC critical section, no GCs will occur. 
+        /// 
+        /// This may throw an <see cref="EntryPointNotFoundException"/> if the build of Mono the game is running on does
+        /// not have `mono_unity_gc_enable` exported. Use with caution.
+        /// </note>
+        public static void ExitGCSection()
+        {
+            mono_unity_gc_enable();
+        }
+
+        #endregion
+
     }
 }