Reuse of a thread-local return data structure to prevent a return data structure from being allocated every time asynchronous functions return. The system returns thread operation from the asynchronous function back to the caller function in a manner that the return data structure can be reused for future asynchronous function returns within that same thread. To do so, the system first accesses data that was generated by the asynchronous function in response to the caller function placing the function call to the asynchronous function. To determine if reuse is appropriate, the system determines that the caller function will use the return data structure as populated only once. If so, the system populates the reusable thread-local return data structure and returns that data structure to the caller.