properties: Use a mutex instead of an RWLock to guard the hash table

The hash table can be recursively locked from the same thread, which can cause issues with RWLocks, as locking them recursively can result in undefined behavior or deadlocks. Use a mutex instead, as it can be safely recursively locked.

src/SDL_properties.c

@@ -49,7 +49,7 @@ typedef struct
 } SDL_Properties;
 
 static SDL_HashTable *SDL_properties;
-static SDL_RWLock *SDL_properties_lock;
+static SDL_Mutex *SDL_properties_lock;
 static SDL_PropertiesID SDL_last_properties_id;
 static SDL_PropertiesID SDL_global_properties;
 
@@ -97,7 +97,7 @@ static void SDL_FreeProperties(const void *key, const void *value, void *data)
 int SDL_InitProperties(void)
 {
     if (!SDL_properties_lock) {
-        SDL_properties_lock = SDL_CreateRWLock();
+        SDL_properties_lock = SDL_CreateMutex();
         if (!SDL_properties_lock) {
             return -1;
         }
@@ -122,7 +122,7 @@ void SDL_QuitProperties(void)
         SDL_properties = NULL;
     }
     if (SDL_properties_lock) {
-        SDL_DestroyRWLock(SDL_properties_lock);
+        SDL_DestroyMutex(SDL_properties_lock);
         SDL_properties_lock = NULL;
     }
 }
@@ -162,7 +162,7 @@ SDL_PropertiesID SDL_CreateProperties(void)
         goto error;
     }
 
-    SDL_LockRWLockForWriting(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     ++SDL_last_properties_id;
     if (SDL_last_properties_id == 0) {
         ++SDL_last_properties_id;
@@ -171,7 +171,7 @@ SDL_PropertiesID SDL_CreateProperties(void)
     if (SDL_InsertIntoHashTable(SDL_properties, (const void *)(uintptr_t)props, properties)) {
         inserted = SDL_TRUE;
     }
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (inserted) {
         /* All done! */
@@ -191,9 +191,9 @@ int SDL_LockProperties(SDL_PropertiesID props)
         return SDL_InvalidParamError("props");
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         return SDL_InvalidParamError("props");
@@ -211,9 +211,9 @@ void SDL_UnlockProperties(SDL_PropertiesID props)
         return;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         return;
@@ -236,9 +236,9 @@ static int SDL_PrivateSetProperty(SDL_PropertiesID props, const char *name, SDL_
         return SDL_InvalidParamError("name");
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_FreeProperty(NULL, property, NULL);
@@ -366,9 +366,9 @@ SDL_PropertyType SDL_GetPropertyType(SDL_PropertiesID props, const char *name)
         return SDL_PROPERTY_TYPE_INVALID;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_InvalidParamError("props");
@@ -403,9 +403,9 @@ void *SDL_GetProperty(SDL_PropertiesID props, const char *name, void *default_va
         return value;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_InvalidParamError("props");
@@ -448,9 +448,9 @@ const char *SDL_GetStringProperty(SDL_PropertiesID props, const char *name, cons
         return value;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_InvalidParamError("props");
@@ -525,9 +525,9 @@ Sint64 SDL_GetNumberProperty(SDL_PropertiesID props, const char *name, Sint64 de
         return value;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_InvalidParamError("props");
@@ -578,9 +578,9 @@ float SDL_GetFloatProperty(SDL_PropertiesID props, const char *name, float defau
         return value;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_InvalidParamError("props");
@@ -631,9 +631,9 @@ SDL_bool SDL_GetBooleanProperty(SDL_PropertiesID props, const char *name, SDL_bo
         return value;
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         SDL_InvalidParamError("props");
@@ -686,9 +686,9 @@ int SDL_EnumerateProperties(SDL_PropertiesID props, SDL_EnumeratePropertiesCallb
         return SDL_InvalidParamError("callback");
     }
 
-    SDL_LockRWLockForReading(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_FindInHashTable(SDL_properties, (const void *)(uintptr_t)props, (const void **)&properties);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 
     if (!properties) {
         return SDL_InvalidParamError("props");
@@ -715,7 +715,7 @@ void SDL_DestroyProperties(SDL_PropertiesID props)
         return;
     }
 
-    SDL_LockRWLockForWriting(SDL_properties_lock);
+    SDL_LockMutex(SDL_properties_lock);
     SDL_RemoveFromHashTable(SDL_properties, (const void *)(uintptr_t)props);
-    SDL_UnlockRWLock(SDL_properties_lock);
+    SDL_UnlockMutex(SDL_properties_lock);
 }