Synchronous Functions

An operation that completes synchronously performs all of its processing in the function call made by the application. The function returns different values depending on its success or failure:

• Synchronous Success. If the request or service corresponding to the function has been carried out successfully, the function returns zero, indicating success. Any values written as a result of the function call are reliable and can be used immediately.
• Synchronous Failure. If the function detects an error and the request is not carried out, a negative error number is returned to identify the error.