This macro starts up the LispWorks program profiler. This tool is useful for determining the time critical elements of a program.

At a regular time interval the Lisp process is halted and the execution stack is scanned for the presence of any symbols in the list *profile-symbol-list*. Counters are maintained for the number of calls to each symbol, the total number of times the symbol is found on the stack, and the number of times the profiler finds the symbol on the top of the stack.

This information is then presented as absolute numbers and as a percentage of the total number of calls to the profiler. These figures taken together give useful information about which functions the program spends most of its time executing.

(set-up-profiler

:symbols '(* sqrt floor))

=>

20

(profile

(let ((x 1))

(loop for a from 1 to 500000

do (setq x (floor (* a (sqrt x))))

finally (return (integer-length x)))))

=>

profile-stacks called 401 times

Call tree

Symbol seen (%)

1: "CAPI Execution Listener 1" 401 (100)

2: * 5 ( 1)

2: SQRT 4 ( 1)

2: FLOOR 1 ( 0)

Cumulative profile summary

Symbol called profile (%) top (%)

* 0 5 ( 1) 0 ( 0)

SQRT 0 4 ( 1) 1 ( 0)

FLOOR 0 1 ( 0) 0 ( 0)

On average 1.0 stacks profiled each profiler invocation

Top of stack not monitored 100% of the time

38

*LispWorks User Guide and Reference Manual - 21 Dec 2011*