~niemeyer/tomb/trunk : changes

~niemeyer/tomb/trunk » Changes from revision 18

From Revision 18

Rev	Summary	Authors	Tags	Date
18	Project moved to https://gopkg.in/tomb.v1 Project moved to https://gopkg.in/tomb.v1	Gustavo Niemeyer		2014-05-29
17	Fix race found by race detector, and reported by Dave Cheney... Fix race found by race detector, and reported by Dave Cheney. Here is more information than you'll want to know: If goroutine 1 is doing: t.Kill(nil) t.Wait() and goroutine 2 is doing: t.Wait() and goroutine 3 is doing: t.Done() There is a race, because goroutine 3 could finish first, and then goroutine 1 might run, and the memory model won't guarantee that goroutine 2 actually sees t.reason recorded by the Kill(nil) of goroutine 1. This specific case is more of a theoretical problem than a real one, for the following reasons: - The memory model guarantees that the close(t.done) performed by t.Done() will Happen Before the <-t.done done by either t.Wait, which means both goroutine 1 and 2 will always necessarily see a real error coming out of the goroutine(s) being monitored by t. - The Kill(nil) performed by goroutine 1 won't affect the value of t.reason due to the logic in the Kill method (although, observing the memory model pedantically means goroutine 1 might do whatever it pleases with the memory region, due to lack of synchronization). In a different scenario, though, t.Kill in goroutine 1 might be performed with a non-nil error, and goroutine 2 would see either nil or the error, and t.reason might be in an intermediate unknown state, so the race is in fact real. Solving this specific race via a mutex, as done in this change, still won't mean that this behavior is sane, though: what t.Wait() in goroutine 2 observes will be either the prior error value, or the new error value, based purely on timing of the two Wait calls. The change introduced protects t.reason with the tomb's mutex, which silents the race detector, and makes the logic entirely memory-model friendly.	Gustavo Niemeyer		2013-05-31
16	Added link to Roger's multi-goroutine example. Added link to Roger's multi-goroutine example.	Gustavo Niemeyer		2012-04-04
15	Fixed a couple of typos. Fixed a couple of typos.	Gustavo Niemeyer		2012-04-03
14	Added ErrDying. Renamed ErrStillRunning to ErrStillAlive. Added ErrDying. Renamed ErrStillRunning to ErrStillAlive. R=TheMue CC= https://codereview.appspot.com/5981052	Gustavo Niemeyer		2012-04-03
13	tomb: update API tomb: update API - Rename Fatal and Fatalf to Kill and Killf. - The Stop error value is gone. Use nil now. - Err will now return ErrStillRunning if the goroutine isn't dead yet, which means a nil return reflects an actual nil Kill call. - Make zero-value of Tomb good to use, and as a consequence, make Dead and Dying into methods rather than fields. R=niemeyer CC= https://codereview.appspot.com/5755055	Roger Peppe		2012-03-06
12	Ported to current weekly. Ported to current weekly.	Gustavo Niemeyer		2012-01-18
11	Fixed typo in Done doc. Fixed typo in Done doc.	Gustavo Niemeyer	go.r60	2011-10-23
10	Clarified doc for Fatal. Clarified doc for Fatal.	Gustavo Niemeyer		2011-10-23
9	Simplified doc for Err. Simplified doc for Err.	Gustavo Niemeyer		2011-10-23
8	Simplified interface after some real use. Simplified interface after some real use.	Gustavo Niemeyer		2011-10-23
7	s/nothing/struct{}/. s/nothing/struct{}/.	Gustavo Niemeyer		2011-10-19
6	Another doc tweak. Another doc tweak.	Gustavo Niemeyer		2011-10-10
5	s/puts/informs/ in documentation. More proper. s/puts/informs/ in documentation. More proper.	Gustavo Niemeyer		2011-10-09
4	Mentioned the blog post in docs. Mentioned the blog post in docs.	Gustavo Niemeyer		2011-10-09
3	Tweaked documentation further. Tweaked documentation further.	Gustavo Niemeyer		2011-10-09
2	Minor tweak in the package tag line. Minor tweak in the package tag line.	Gustavo Niemeyer		2011-10-09
1	Implemented it. :-) Implemented it. :-)	Gustavo Niemeyer		2011-10-09