From 3b39ed9d10274e9fff748a0e5b98aa62134a64e8 Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Wed, 15 Dec 2021 14:24:00 -0800
Subject: [PATCH] fix possible race condition in OnBufferEndCallback

---
 gamemaker/extensions/FAudioGMS/FAudioGMS.dll |  2 +-
 src/FAudioGMS.c                              | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/gamemaker/extensions/FAudioGMS/FAudioGMS.dll b/gamemaker/extensions/FAudioGMS/FAudioGMS.dll
index e3bc0f0..eb24139 100644
--- a/gamemaker/extensions/FAudioGMS/FAudioGMS.dll
+++ b/gamemaker/extensions/FAudioGMS/FAudioGMS.dll
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:21c45d674003ac89a5227f8984941cbd26d358f7b089b21c5bdbe75442491acc
+oid sha256:da07c6285594a2be3dd90139952d3ba038f7a9004ba4623d59d50c03cc18657a
 size 1522176
diff --git a/src/FAudioGMS.c b/src/FAudioGMS.c
index 80cfd06..f7c144a 100644
--- a/src/FAudioGMS.c
+++ b/src/FAudioGMS.c
@@ -268,6 +268,8 @@ typedef struct FAudioGMS_Device
     IdStack effectChainIndexStack;
 
     double timestep;
+
+    SDL_mutex *destroyMutex;
 } FAudioGMS_Device;
 
 static FAudioGMS_Device *device = NULL;
@@ -386,9 +388,11 @@ static void FAudioGMS_INTERNAL_OnBufferEndCallback(
 
         if (instance->destroyOnFinish)
         {
+            SDL_LockMutex(device->destroyMutex);
+
             /* this is a callback so we don't want to immediately destroy and screw up data */
             instance->destroyTimerActive = 1;
-            instance->destroyTimer = 0;
+            instance->destroyTimer = 10; /* a little wiggle room */
 
             if (instance->voice.effectChainAttached)
             {
@@ -403,6 +407,8 @@ static void FAudioGMS_INTERNAL_OnBufferEndCallback(
                     }
                 }
             }
+
+            SDL_UnlockMutex(device->destroyMutex);
         }
     }
 }
@@ -542,6 +548,8 @@ void FAudioGMS_Init(double spatialDistanceScale, double timestep)
 
     device->timestep = timestep;
 
+    device->destroyMutex = SDL_CreateMutex();
+
     Log("FAudio initialized successfully!");
 }
 
@@ -2115,6 +2123,7 @@ void FAudioGMS_Update()
                 FAudioGMS_INTERNAL_SoundInstance_SetVolume(instance, volume);
             }
 
+            SDL_LockMutex(device->destroyMutex);
             if (instance->destroyTimerActive)
             {
                 instance->destroyTimer -= device->timestep;
@@ -2124,6 +2133,7 @@ void FAudioGMS_Update()
                     FAudioGMS_INTERNAL_SoundInstance_Destroy(instance);
                 }
             }
+            SDL_UnlockMutex(device->destroyMutex);
         }
     }
 }
@@ -2195,6 +2205,7 @@ void FAudioGMS_Destroy()
     SDL_free(device->fauxMasteringVoice.sends.pSends);
 
     FAudio_Release(device->handle);
+    SDL_DestroyMutex(device->destroyMutex);
     SDL_free(device);
     device = NULL;