Removed SDL_FreeTemporaryMemory()

This was just causing confusion and anxiety. SDL temporary memory will be automatically freed on the main thread when processing events and on other threads when it ages out after a second. The application can free it directly by calling SDL_ClaimTemporaryMemory() to get ownership of the pointer, if necessary.

src/dynapi/SDL_dynapi.sym

@@ -130,7 +130,6 @@ SDL3_0.0.0 {
     SDL_FlushEvent;
     SDL_FlushEvents;
     SDL_FlushRenderer;
-    SDL_FreeTemporaryMemory;
     SDL_GDKSuspendComplete;
     SDL_GL_CreateContext;
     SDL_GL_DestroyContext;

src/dynapi/SDL_dynapi_overrides.h

@@ -155,7 +155,6 @@
 #define SDL_FlushEvent SDL_FlushEvent_REAL
 #define SDL_FlushEvents SDL_FlushEvents_REAL
 #define SDL_FlushRenderer SDL_FlushRenderer_REAL
-#define SDL_FreeTemporaryMemory SDL_FreeTemporaryMemory_REAL
 #define SDL_GDKSuspendComplete SDL_GDKSuspendComplete_REAL
 #define SDL_GL_CreateContext SDL_GL_CreateContext_REAL
 #define SDL_GL_DestroyContext SDL_GL_DestroyContext_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -175,7 +175,6 @@ SDL_DYNAPI_PROC(int,SDL_FlushAudioStream,(SDL_AudioStream *a),(a),return)
 SDL_DYNAPI_PROC(void,SDL_FlushEvent,(Uint32 a),(a),)
 SDL_DYNAPI_PROC(void,SDL_FlushEvents,(Uint32 a, Uint32 b),(a,b),)
 SDL_DYNAPI_PROC(int,SDL_FlushRenderer,(SDL_Renderer *a),(a),return)
-SDL_DYNAPI_PROC(void,SDL_FreeTemporaryMemory,(const void *a),(a),)
 SDL_DYNAPI_PROC(void,SDL_GDKSuspendComplete,(void),(),)
 SDL_DYNAPI_PROC(SDL_GLContext,SDL_GL_CreateContext,(SDL_Window *a),(a),return)
 SDL_DYNAPI_PROC(int,SDL_GL_DestroyContext,(SDL_GLContext a),(a),return)

src/events/SDL_events.c

@@ -74,6 +74,7 @@ static Uint32 SDL_userevents = SDL_EVENT_USER;
 typedef struct SDL_TemporaryMemory
 {
     void *memory;
+    Uint64 timestamp;
     struct SDL_TemporaryMemory *prev;
     struct SDL_TemporaryMemory *next;
 } SDL_TemporaryMemory;
@@ -105,11 +106,13 @@ static struct
     SDL_EventEntry *free;
 } SDL_EventQ = { NULL, SDL_FALSE, { 0 }, 0, NULL, NULL, NULL };
 
+static void SDL_FreeTemporaryMemory(void);
+
 static void SDL_CleanupTemporaryMemory(void *data)
 {
     SDL_TemporaryMemoryState *state = (SDL_TemporaryMemoryState *)data;
 
-    SDL_FreeTemporaryMemory(NULL);
+    SDL_FreeTemporaryMemory();
     SDL_free(state);
 }
 
@@ -260,6 +263,23 @@ static void SDL_TransferTemporaryMemoryFromEvent(SDL_EventEntry *event)
     event->memory = NULL;
 }
 
+static void SDL_CollectTemporaryMemory(SDL_TemporaryMemoryState *state, Uint64 now)
+{
+    // Temporary memory will age out and be collected after 1 second
+    const int TEMPORARY_MEMORY_COLLECT_TIME_MS = 1000;
+
+    while (state->head) {
+        SDL_TemporaryMemory *entry = state->head;
+
+        if ((now - entry->timestamp) < TEMPORARY_MEMORY_COLLECT_TIME_MS) {
+            break;
+        }
+
+        SDL_UnlinkTemporaryMemoryEntry(state, entry);
+        SDL_FreeTemporaryMemoryEntry(state, entry, SDL_TRUE);
+    }
+}
+
 void *SDL_FreeLater(void *memory)
 {
     SDL_TemporaryMemoryState *state;
@@ -276,12 +296,16 @@ void *SDL_FreeLater(void *memory)
         return memory;  // this is now a leak, but you probably have bigger problems if malloc failed.
     }
 
+    Uint64 now = SDL_GetTicks();
+    SDL_CollectTemporaryMemory(state, now);
+
     SDL_TemporaryMemory *entry = (SDL_TemporaryMemory *)SDL_malloc(sizeof(*entry));
     if (!entry) {
         return memory;  // this is now a leak, but you probably have bigger problems if malloc failed. We could probably pool up and reuse entries, though.
     }
 
     entry->memory = memory;
+    entry->timestamp = now;
 
     SDL_LinkTemporaryMemoryEntry(state, entry);
 
@@ -317,7 +341,7 @@ void *SDL_ClaimTemporaryMemory(const void *mem)
     return NULL;
 }
 
-void SDL_FreeTemporaryMemory(const void *mem)
+void SDL_FreeTemporaryMemory(void)
 {
     SDL_TemporaryMemoryState *state;
 
@@ -326,19 +350,11 @@ void SDL_FreeTemporaryMemory(const void *mem)
         return;
     }
 
-    if (mem) {
-        SDL_TemporaryMemory *entry = SDL_GetTemporaryMemoryEntry(state, mem);
-        if (entry) {
-            SDL_UnlinkTemporaryMemoryEntry(state, entry);
-            SDL_FreeTemporaryMemoryEntry(state, entry, SDL_TRUE);
-        }
-    } else {
-        while (state->head) {
-            SDL_TemporaryMemory *entry = state->head;
+    while (state->head) {
+        SDL_TemporaryMemory *entry = state->head;
 
-            SDL_UnlinkTemporaryMemoryEntry(state, entry);
-            SDL_FreeTemporaryMemoryEntry(state, entry, SDL_TRUE);
-        }
+        SDL_UnlinkTemporaryMemoryEntry(state, entry);
+        SDL_FreeTemporaryMemoryEntry(state, entry, SDL_TRUE);
     }
 }
 
@@ -862,7 +878,7 @@ void SDL_StopEventLoop(void)
     SDL_EventQ.free = NULL;
     SDL_AtomicSet(&SDL_sentinel_pending, 0);
 
-    SDL_FreeTemporaryMemory(NULL);
+    SDL_FreeTemporaryMemory();
 
     /* Clear disabled event state */
     for (i = 0; i < SDL_arraysize(SDL_disabled_events); ++i) {
@@ -1159,7 +1175,7 @@ static void SDL_PumpEventsInternal(SDL_bool push_sentinel)
     SDL_VideoDevice *_this = SDL_GetVideoDevice();
 
     /* Free old event memory */
-    SDL_FreeTemporaryMemory(NULL);
+    SDL_FreeTemporaryMemory();
 
     /* Release any keys held down from last frame */
     SDL_ReleaseAutoReleaseKeys();