Assembly: PostSharp (in PostSharp.dll) Version: 18.104.22.168 (22.214.171.124)
void OnYield( MethodExecutionArgs args )
In iterator methods, this advise is exactly executed at the yield return statement.
In async methods, the advice is executed just after the state machine starts waiting as a result of the await statement. In case the operand of the await statement is an operation that completed synchronously, the state machine does not yield, and the advise won't be invoked.