docs: Mark most of SDL_filesystem.h as thread-safe.

Fixes #13738.

include/SDL3/SDL_filesystem.h

@@ -89,6 +89,8 @@ extern "C" {
  *          doesn't implement this functionality, call SDL_GetError() for more
  *          information.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  *
  * \sa SDL_GetPrefPath
@@ -150,6 +152,8 @@ extern SDL_DECLSPEC const char * SDLCALL SDL_GetBasePath(void);
  *          etc.). This should be freed with SDL_free() when it is no longer
  *          needed.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  *
  * \sa SDL_GetBasePath
@@ -222,6 +226,8 @@ typedef enum SDL_Folder
  * \returns either a null-terminated C string containing the full path to the
  *          folder, or NULL if an error happened.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC const char * SDLCALL SDL_GetUserFolder(SDL_Folder folder);
@@ -289,6 +295,8 @@ typedef Uint32 SDL_GlobFlags;
  * \returns true on success or false on failure; call SDL_GetError() for more
  *          information.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_CreateDirectory(const char *path);
@@ -352,6 +360,8 @@ typedef SDL_EnumerationResult (SDLCALL *SDL_EnumerateDirectoryCallback)(void *us
  * \returns true on success or false on failure; call SDL_GetError() for more
  *          information.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_EnumerateDirectory(const char *path, SDL_EnumerateDirectoryCallback callback, void *userdata);
@@ -366,6 +376,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_EnumerateDirectory(const char *path, SDL_En
  * \returns true on success or false on failure; call SDL_GetError() for more
  *          information.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_RemovePath(const char *path);
@@ -389,6 +401,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_RemovePath(const char *path);
  * \returns true on success or false on failure; call SDL_GetError() for more
  *          information.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_RenamePath(const char *oldpath, const char *newpath);
@@ -429,6 +443,10 @@ extern SDL_DECLSPEC bool SDLCALL SDL_RenamePath(const char *oldpath, const char
  * \returns true on success or false on failure; call SDL_GetError() for more
  *          information.
  *
+ * \threadsafety It is safe to call this function from any thread, but this
+ *               operation is not atomic, so the app might need to protect
+ *               access to specific paths from other threads if appropriate.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_CopyFile(const char *oldpath, const char *newpath);
@@ -442,6 +460,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_CopyFile(const char *oldpath, const char *n
  * \returns true on success or false if the file doesn't exist, or another
  *          failure; call SDL_GetError() for more information.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_GetPathInfo(const char *path, SDL_PathInfo *info);
@@ -496,6 +516,8 @@ extern SDL_DECLSPEC char ** SDLCALL SDL_GlobDirectory(const char *path, const ch
  *          platform-dependent notation. NULL if there's a problem. This
  *          should be freed with SDL_free() when it is no longer needed.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.2.0.
  */
 extern SDL_DECLSPEC char * SDLCALL SDL_GetCurrentDirectory(void);