596676 - Make the JavaScript shell print out how long it takes to run a script

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

For simple testing on the command line, it would be nice to print out how long it took to run a script. Doing 'time js ...' is pretty inaccurate.

Comment 1

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: fix

This adds a command line option to the shell so that running 'js -p ...' prints out a line like the following:
  runtime = 19374 ns
I find it useful.

Comment 2

[David Mandelin [:dmandelin]]

Comment on attachment 475565 [details] [diff] [review]
fix

Nice idea. I've been putting "var t0 = new Date; print(new Date - t0)" into test files for months.

>+            if (!compileOnly) {
>+                int64 t1 = PRMJ_Now();
>                 (void)JS_ExecuteScript(cx, obj, script, NULL);
>+                int64 t2 = PRMJ_Now() - t1;
>+                if (printTiming) printf("runtime = %ld ns\n", t2);
>+            }

- PRMJ_Now returns microseconds, so you probably means "us" for the unit. But maybe it would be better to print ms with a fractional digit or two?

- I think "%lld" is what does with JSInt64. 

- Style nit: |if (printTiming) printf("runtime = %ld ns\n", t2);| must be two lines:

    if (printTiming)
        printf("runtime = %ld ns\n", t2);

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: updated patch

OK, now with less brain damage.

Comment 4

[David Mandelin [:dmandelin]]

Comment on attachment 475574 [details] [diff] [review]
updated patch

Use PRMJ_USEC_PER_MSEC instead of 1000. Otherwise, r+.

Comment 5

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

http://hg.mozilla.org/tracemonkey/rev/f7206e5fe349

Comment 6

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/f7206e5fe349