firefox 21.0a1 (2013-01-16) addons are up to date Error: Failure parsing JSON data Error: Failure parsing JSON data: {"timestamp": 1359558330688000, "total_time": 5755.9, "compartments_collected": 970, "total_compartments": 970, "mmu_20ms": 0, "mmu_50ms": 0, "scc_sweep_total": 275.9, "scc_sweep_max_pause": 68.6, "max_pause": 158.8, "nonincremental_reason": "none", "allocated": 375, "added_chunks": 0, "removed_chunks": 0, "slices": [{"slice": 0, "pause": 102.8, "when": 0.0, "reason": "CC_WAITING", "page_faults": 73.0, "start_timestamp": 1359558315208597, "end_timestamp": 1359558315311440, "times": {"begin_callback": 0.1, "wait_background_thread": 0.0, "mark_discard_code": 28.7, "purge": 0.4, "mark": 58.9, "mark_roots": 58.5, "mark_types": 0.0, "mark_delayed": 0.0, "sweep": 0.0, "mark_during_sweeping": 0.0, "mark_types_during_sweeping": 0.0, "mark_delayed_during_sweeping": 0.0, "mark_incoming_black_pointers": 0.0, "mark_weak": 0.0, "mark_incoming_gray_pointers": 0.0, "mark_gray": 0.0, ... Source File: resource://gre/modules/XPIProvider.jsm -> jar:file:///C:/Users/Wayne/AppData/Roaming/Mozilla/Firefox/Profiles/3nviu178.Phoenix/extensions/memchaser@quality.mozilla.org.xpi!/bootstrap.js -> resource://memchaser-at-quality-dot-mozilla-dot-org/api-utils/lib/loader.js -> resource://memchaser-at-quality-dot-mozilla-dot-org/memchaser/lib/garbage-collector.js Line: 75

the JSON data is about 430k. This might also be a source of recent EMPTY crashes for me - bp-72c93f7f-3c23-47be-aebe-0df692130130

Can you please file an issue here: https://github.com/mozilla/memchaser

Also please provide a full example of the json blob.

issue filed https://github.com/mozilla/memchaser/issues/161

bug 507998 might help here

This is causing my heartache on trunk. from https://github.com/mozilla/memchaser/issues/161 ... I made a page with var jsObject = JSON.parse(json-data...); and what I get from Firefox is SyntaxError: missing ) after argument list @ file:///C:/Users/Wayne/Documents/json.html:3 It's not because of unmatched { } - there are equal number in the data. And it does not appear to be size related, because I did a much smaller blob 69k with a different set of mem data (I'll send you [Henrik] the data) and got back Timestamp: 3/21/2013 3:41:30 PM Error: SyntaxError: JSON.parse: unexpected character Source File: file:///C:/Users/Wayne/Documents/jsontoday.html Line: 3

still seeing this, current trunk. what's next step?

I incorrectly copied the bits of the last attachment and left the trailing file reference at the bottom. With the updated data I cannot see a problem by inspecting the data on http://jsonviewer.stack.hu/. All looks fine. As it looks like something is broken in JSON.parse()?

Ok, so the problem here seems to be related to some non-parseable fractional numbers for one of the listed values. Seems like we are broken here on the JS side and are creating bad numbers: "JSON.parse: unterminated fractional number" The following two examples I took from the attached failure cases: {"slice": 299, "pause": -11.-2, [..] } "totals": { [..] "finalize_end_callback": -19.-3, } Terrence, given that you have implemented most of it, do you have an idea?

Great find! Yes, I know what's going on: appendDecimal does not handle negative numbers correctly. We should definitely fix this specific bug, however, the larger question is how the negative times got in there in the first place. Slices are strictly ordered such that this should be impossible unless someone manually adjusts their clock backwards. Is this Windows only? The optimizations we do for timekeeping on that platform may be implicated here.

Good question. Lets ask Wayne on which platform he is on. Lately I haven't checked the browser console for such issues, so I cannot give a qualified answer. But I think I noticed something like that months ago on OS X.

Since negative times are meaningless here, but probably small, we should just truncate to zero.

Comment on attachment 812114 [details] [diff] [review] v0: Handle negative slice times Review of attachment 812114 [details] [diff] [review]: ----------------------------------------------------------------- That's weird.

I experience this on vista laptop. I never adjust the clock. But I run daily/trunk. And the laptop goes through sleep/wake cycles as it gets transported.

https://hg.mozilla.org/integration/mozilla-inbound/rev/fd872b99606c In general, if ntp or the rtc tells the OS that it's clock is a few milliseconds fast, the OS should not just warp the clock backwards a few milliseconds. This would result in applications seeing time run backwards, resulting in problems like this. Instead the OS should be incrementally delaying future ticks so that the clock slowly drifts back into alignment. Either that is not happening on some machines or we have a bug in how slices record time.