Open Radar

 
Summary:

Listening to "message" events on safari.self.tab within a content script of a Safari extension makes the SunSpider Javascript benchmark 1.132 as slow:

http://www.webkit.org/perf/sunspider-0.9.1/sunspider-0.9.1/results.html?%7B%22v%22:%20%22sunspider-0.9.1%22,%20%223d-cube%22:%5B15,15,17,17,17,17,17,18,18,18%5D,%223d-morph%22:%5B12,12,11,12,12,12,12,12,12,12%5D,%223d-raytrace%22:%5B15,15,16,16,16,16,16,17,17,17%5D,%22access-binary-trees%22:%5B8,7,9,9,10,10,11,11,11,11%5D,%22access-fannkuch%22:%5B18,18,17,17,17,19,17,17,17,18%5D,%22access-nbody%22:%5B10,11,10,11,11,11,11,11,10,11%5D,%22access-nsieve%22:%5B5,5,5,5,5,5,5,5,5,5%5D,%22bitops-3bit-bits-in-byte%22:%5B3,3,3,3,3,3,4,4,3,3%5D,%22bitops-bits-in-byte%22:%5B7,7,8,8,8,7,7,7,7,7%5D,%22bitops-bitwise-and%22:%5B4,5,4,5,4,4,4,5,4,4%5D,%22bitops-nsieve-bits%22:%5B8,8,8,8,8,7,8,8,7,8%5D,%22controlflow-recursive%22:%5B4,4,4,4,4,3,3,4,4,3%5D,%22crypto-aes%22:%5B13,13,14,14,15,16,16,16,16,17%5D,%22crypto-md5%22:%5B5,4,4,4,5,4,5,4,4,4%5D,%22crypto-sha1%22:%5B4,3,4,4,4,3,3,3,3,3%5D,%22date-format-tofte%22:%5B26,27,28,29,29,30,30,31,32,31%5D,%22date-format-xparb%22:%5B19,19,23,22,22,22,23,23,24,24%5D,%22math-cordic%22:%5B10,10,10,9,10,10,10,9,10,9%5D,%22math-partial-sums%22:%5B15,15,15,14,15,15,15,15,15,15%5D,%22math-spectral-norm%22:%5B7,6,7,7,7,7,6,6,6,7%5D,%22regexp-dna%22:%5B17,16,17,16,17,17,17,16,17,17%5D,%22string-base64%22:%5B16,18,19,19,20,21,21,22,23,23%5D,%22string-fasta%22:%5B15,16,16,17,17,17,17,17,19,18%5D,%22string-tagcloud%22:%5B23,23,24,25,25,25,25,25,25,26%5D,%22string-unpack-code%22:%5B43,45,46,45,46,48,46,47,48,48%5D,%22string-validate-input%22:%5B23,25,27,26,27,28,28,29,29,30%5D%7D

compared to:

http://www.webkit.org/perf/sunspider-0.9.1/sunspider-0.9.1/results.html?%7B%22v%22:%20%22sunspider-0.9.1%22,%20%223d-cube%22:%5B16,15,15,15,14,14,14,14,15,15%5D,%223d-morph%22:%5B12,11,12,12,12,11,12,12,12,11%5D,%223d-raytrace%22:%5B15,15,14,15,15,15,15,15,15,14%5D,%22access-binary-trees%22:%5B6,6,6,7,6,6,6,7,6,6%5D,%22access-fannkuch%22:%5B18,17,20,19,18,17,17,18,18,17%5D,%22access-nbody%22:%5B11,10,10,11,11,10,10,11,10,10%5D,%22access-nsieve%22:%5B5,5,5,6,5,5,5,5,5,5%5D,%22bitops-3bit-bits-in-byte%22:%5B3,4,3,3,3,3,4,3,4,4%5D,%22bitops-bits-in-byte%22:%5B7,7,7,7,7,7,8,7,7,8%5D,%22bitops-bitwise-and%22:%5B4,4,4,4,5,4,5,4,4,4%5D,%22bitops-nsieve-bits%22:%5B7,8,8,8,7,8,8,8,8,8%5D,%22controlflow-recursive%22:%5B3,3,4,3,3,3,4,4,4,4%5D,%22crypto-aes%22:%5B12,12,12,13,12,12,12,12,12,12%5D,%22crypto-md5%22:%5B5,5,4,5,4,4,4,4,4,4%5D,%22crypto-sha1%22:%5B4,3,4,4,3,3,3,4,3,4%5D,%22date-format-tofte%22:%5B25,25,24,25,25,24,25,25,25,24%5D,%22date-format-xparb%22:%5B18,18,17,18,18,18,17,18,17,18%5D,%22math-cordic%22:%5B9,9,10,9,9,10,9,9,10,9%5D,%22math-partial-sums%22:%5B15,15,15,15,17,15,15,15,14,15%5D,%22math-spectral-norm%22:%5B7,7,6,7,7,6,7,6,6,6%5D,%22regexp-dna%22:%5B16,16,16,17,16,17,16,16,16,16%5D,%22string-base64%22:%5B14,14,14,14,14,15,14,14,14,14%5D,%22string-fasta%22:%5B15,15,14,14,14,14,14,14,14,14%5D,%22string-tagcloud%22:%5B22,22,22,22,22,22,22,22,22,22%5D,%22string-unpack-code%22:%5B41,40,40,41,41,40,41,42,41,41%5D,%22string-validate-input%22:%5B21,20,21,20,21,20,20,20,21,20%5D%7D

Steps to Reproduce:

Install the attached extension, which has the following injected script:

safari.self.addEventListener("message", respondToMessage, false);
function respondToMessage(event) {}

Disable all other extensions and run the SunSpider test at http://www.webkit.org/perf/sunspider/sunspider.html.

Expected Results:

No significant difference with or without the extension.

Actual Results:

1.132 times as slow with the extension!

Regression: ?

Notes:

This is the reason most extensions make the SunSpider test crawl.