9.7.2 Timed Entry Calls
A timed_entry_call issues an entry call that is cancelled if the call (or a requeue-with-abort of the call) is not selected before the expiration time is reached.
timed_entry_call ::= select entry_call_alternative or delay_alternative end select;
entry_call_alternative ::= entry_call_statement [sequence_of_statements]
For the execution of a timed_entry_call, the entry_name and the actual parameters are evaluated, as for a simple entry call (see 9.5.3). The expiration time (see 9.6) for the call is determined by evaluating the delay_expression of the delay_alternative; the entry call is then issued.
If the call is queued (including due to a requeue-with-abort), and not selected before the expiration time is reached, an attempt to cancel the call is made. If the call completes due to the cancellation, the optional sequence_of_statements of the delay_alternative is executed; if the entry call completes normally, the optional sequence_of_statements of the entry_call_alternative is executed.
Example of a timed entry call:
select Controller.Request(Medium)(Some_Item); or delay 45.0; -- controller too busy, try something else end select;
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Copyright © 2000 The MITRE Corporation, Inc. Ada Reference Manual