D.14.3 Execution Time of Interrupt Handlers

This subclause describes a language-defined package to measure the execution time of interrupt handlers. 

The following language-defined library package exists: 

The execution time or CPU time of a given interrupt Interrupt is defined as the time spent by the system executing interrupt handlers identified by Interrupt, including the time spent executing run-time or system services on its behalf. The mechanism used to measure execution time is implementation defined. Time spent executing interrupt handlers is distinct from time spent executing any task. 

For each interrupt, the execution time value is initially set to zero. 

The function Clock returns the current cumulative execution time of the interrupt identified by Interrupt. If Separate_Interrupt_Clocks_Supported is set to False the function raises Program_Error.

The function Supported returns True if the implementation is monitoring the execution time of the interrupt identified by Interrupt; otherwise, it returns False. For any Interrupt_Id Interrupt for which Supported(Interrupt) returns False, the function Clock(Interrupt) will return a value equal to Ada.Execution_Time.Time_Of(0).