Thread-local return structure for asynchronous state machine

A computing system for synchronously returning operation from an asynchronous function to a caller function without allocating a return data structure in a heap of the computing system, the computing system comprising:

• one or more processors;
• and
• one or more computer-readable hardware storage devices having stored thereon computer-executable instructions that are structured such that, when executed by the one or more processors, configure the computing system to perform at least:
• execute an asynchronous function in response to a caller function placing a function call to the asynchronous function, the asynchronous function configured to await one or more events and return a value in response to at least one of the one or more events;
• returning, by the asynchronous function, a first value at a first time;
• return, by the asynchronous function, a first value at a first time;
• allocate a thread-local return data structure within a heap of the computing system;
• populate the thread-local return data structure with the first value;
• determine whether the caller function will use the first value only once;
• in response to determining that the caller function will use the first value only once,
• return, by the asynchronous function, a second value at a second time that is later than the first time;
• reallocate the same thread-local return data structure within the heap of the computing system;
• populate the same thread-local return data structure with the second value;
• and
• return the populated thread-local return data structure to the caller function.

A computing program product for compiling intermediate code into binary code that is executable by a runtime comprising one or more hardware storage devices having stored thereon computer-executable instructions that are structured such that, when executed, the computer-executable instructions configure a computing system to perform at least:

• execute an asynchronous function in response to a caller function placing a function call to the asynchronous function, the asynchronous function configured to await one or more events and return a value in response to at least one of the one or more events;
• return, by the asynchronous function, a first value at a first time;
• allocate a thread-local return data structure within a heap of the computing system;
• populate the thread-local return data structure with the first value;
• determine whether the caller function will use the first value only once;
• and
• in response to determining that the caller function will use the first value only once,
• return, by the asynchronous function, a second value at a second time that is later than the first time;
• reallocate the same thread-local return data structure within the heap of the computing system;
• populate the same thread-local return data structure with the second value;
• and
• returning the populated thread-local return data structure to the caller function.