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| author | Yuras Shumovich <shumovichy@gmail.com> | 2014-11-17 19:16:08 -0600 |
|---|---|---|
| committer | Austin Seipp <austin@well-typed.com> | 2014-11-17 19:16:08 -0600 |
| commit | a520761d065a84838896e8dd09d8aaec77480d60 (patch) | |
| tree | ff4037c9f23db7709b8f3e0fb664d16bda961b5c /libraries/base/GHC/Event | |
| parent | d997ca85a33f34f9f461096eb1b25d5f25b53072 (diff) | |
| download | haskell-a520761d065a84838896e8dd09d8aaec77480d60.tar.gz | |
Remove outdated TODO in TimeManager
Summary:
It describes a work around Trac #3838, but it is already fixed and the
workaround removed, Trac #7653
Test Plan: not needed
Reviewers: hvr, Mikolaj, austin
Reviewed By: austin
Subscribers: thomie, carter
Differential Revision: https://phabricator.haskell.org/D478
Diffstat (limited to 'libraries/base/GHC/Event')
| -rw-r--r-- | libraries/base/GHC/Event/TimerManager.hs | 26 |
1 files changed, 0 insertions, 26 deletions
diff --git a/libraries/base/GHC/Event/TimerManager.hs b/libraries/base/GHC/Event/TimerManager.hs index bf6339a4d8..c1ab64c7a9 100644 --- a/libraries/base/GHC/Event/TimerManager.hs +++ b/libraries/base/GHC/Event/TimerManager.hs @@ -81,32 +81,6 @@ data State = Created -- | A priority search queue, with timeouts as priorities. type TimeoutQueue = Q.PSQ TimeoutCallback -{- -Instead of directly modifying the 'TimeoutQueue' in -e.g. 'registerTimeout' we keep a list of edits to perform, in the form -of a chain of function closures, and have the I/O manager thread -perform the edits later. This exist to address the following GC -problem: - -Since e.g. 'registerTimeout' doesn't force the evaluation of the -thunks inside the 'emTimeouts' IORef a number of thunks build up -inside the IORef. If the I/O manager thread doesn't evaluate these -thunks soon enough they'll get promoted to the old generation and -become roots for all subsequent minor GCs. - -When the thunks eventually get evaluated they will each create a new -intermediate 'TimeoutQueue' that immediately becomes garbage. Since -the thunks serve as roots until the next major GC these intermediate -'TimeoutQueue's will get copied unnecessarily in the next minor GC, -increasing GC time. This problem is known as "floating garbage". - -Keeping a list of edits doesn't stop this from happening but makes the -amount of data that gets copied smaller. - -TODO: Evaluate the content of the IORef to WHNF on each insert once -this bug is resolved: http://ghc.haskell.org/trac/ghc/ticket/3838 --} - -- | An edit to apply to a 'TimeoutQueue'. type TimeoutEdit = TimeoutQueue -> TimeoutQueue |