From c2710ffe87dae7d292e77ed9663783e9d5c227dc Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Sun, 28 Jan 2018 16:58:41 -0800
Subject: [PATCH] Make EnabledEvts atomic

---
 Alc/ALc.c                 |  2 +-
 OpenAL32/Include/alMain.h |  2 +-
 OpenAL32/alError.c        |  6 ++++--
 OpenAL32/alState.c        |  6 ++++--
 OpenAL32/event.c          | 19 +++++++++++++++++--
 5 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/Alc/ALc.c b/Alc/ALc.c
index ea387c6d..21cabf5f 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -2554,7 +2554,7 @@ static ALvoid InitContext(ALCcontext *Context)
     ATOMIC_FLAG_TEST_AND_SET(&Context->PropsClean, almemory_order_relaxed);
     ATOMIC_INIT(&Context->DeferUpdates, AL_FALSE);
     almtx_init(&Context->EventLock, almtx_plain);
-    Context->EnabledEvts = 0;
+    ATOMIC_INIT(&Context->EnabledEvts, 0);
     Context->EventCb = NULL;
     Context->EventParam = NULL;
 
diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index 5b31696e..ef5ad0e9 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -665,7 +665,7 @@ struct ALCcontext_struct {
     ATOMIC(struct ALeffectslotArray*) ActiveAuxSlots;
 
     almtx_t EventLock;
-    ALbitfieldSOFT EnabledEvts;
+    ATOMIC(ALbitfieldSOFT) EnabledEvts;
     ALEVENTPROCSOFT EventCb;
     void *EventParam;
 
diff --git a/OpenAL32/alError.c b/OpenAL32/alError.c
index e3909742..22aed458 100644
--- a/OpenAL32/alError.c
+++ b/OpenAL32/alError.c
@@ -72,10 +72,12 @@ void alSetError(ALCcontext *context, ALenum errorCode, const char *msg, ...)
     }
 
     ATOMIC_COMPARE_EXCHANGE_STRONG_SEQ(&context->LastError, &curerr, errorCode);
-    if((context->EnabledEvts&EventType_Error))
+    if((ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed)&EventType_Error))
     {
+        ALbitfieldSOFT enabledevts;
         almtx_lock(&context->EventLock);
-        if((context->EnabledEvts&EventType_Error) && context->EventCb)
+        enabledevts = ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed);
+        if((enabledevts&EventType_Error) && context->EventCb)
             (*context->EventCb)(AL_EVENT_TYPE_ERROR_SOFT, 0, errorCode, msglen, msg,
                                 context->EventParam);
         almtx_unlock(&context->EventLock);
diff --git a/OpenAL32/alState.c b/OpenAL32/alState.c
index d4f3c6cf..10fce3b5 100644
--- a/OpenAL32/alState.c
+++ b/OpenAL32/alState.c
@@ -716,13 +716,15 @@ AL_API ALvoid AL_APIENTRY alDopplerVelocity(ALfloat value)
     context = GetContextRef();
     if(!context) return;
 
-    if((context->EnabledEvts&EventType_Deprecated))
+    if((ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed)&EventType_Deprecated))
     {
         static const ALCchar msg[] =
             "alDopplerVelocity is deprecated in AL1.1, use alSpeedOfSound";
         const ALsizei msglen = (ALsizei)strlen(msg);
+        ALbitfieldSOFT enabledevts;
         almtx_lock(&context->EventLock);
-        if((context->EnabledEvts&EventType_Deprecated) && context->EventCb)
+        enabledevts = ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed);
+        if((enabledevts&EventType_Deprecated) && context->EventCb)
             (*context->EventCb)(AL_EVENT_TYPE_DEPRECATED_SOFT, 0, 0, msglen, msg,
                                 context->EventParam);
         almtx_unlock(&context->EventLock);
diff --git a/OpenAL32/event.c b/OpenAL32/event.c
index 3b70c9f3..93d68d7a 100644
--- a/OpenAL32/event.c
+++ b/OpenAL32/event.c
@@ -39,9 +39,24 @@ AL_API void AL_APIENTRY alEventControlSOFT(ALsizei count, const ALenum *types, A
 
     almtx_lock(&context->EventLock);
     if(enable)
-        context->EnabledEvts |= flags;
+    {
+        ALbitfieldSOFT enabledevts = ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed);
+        while(ATOMIC_COMPARE_EXCHANGE_WEAK(&context->EnabledEvts, &enabledevts, enabledevts|flags,
+                                           almemory_order_acq_rel, almemory_order_acquire) == 0)
+        {
+            /* enabledevts is (re-)filled with the current value on failure, so
+             * just try again.
+             */
+        }
+    }
     else
-        context->EnabledEvts &= ~flags;
+    {
+        ALbitfieldSOFT enabledevts = ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed);
+        while(ATOMIC_COMPARE_EXCHANGE_WEAK(&context->EnabledEvts, &enabledevts, enabledevts&~flags,
+                                           almemory_order_acq_rel, almemory_order_acquire) == 0)
+        {
+        }
+    }
     almtx_unlock(&context->EventLock);
 
 done:
-- 
2.11.4.GIT