[commit: ghc] master: base: Rework System.CPUTime (cb3456d)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/cb3456d82eaa8cea6b393273f0c81c57fb760ee5/ghc

>---------------------------------------------------------------

commit cb3456d82eaa8cea6b393273f0c81c57fb760ee5
Author: Ben Gamari <bgamari.foss at gmail.com>
Date:   Sun Mar 20 17:56:24 2016 +0100

    base: Rework System.CPUTime
    
    This started when I noticed that `getCPUTime` only provides 1
    millisecond resolution on Linux. Unfortunately the previous
    implementation was quite unmaintainable, so this ended up being a bit
    more involved than I expected.
    
    Here we do several things,
    
     * Split up `System.CPUTime`
    
     * Add support for `clock_gettime`, allowing for significantly more
       precise timing information when available
    
     * Fix System.CPUTime resolution for Windows. While it's hard to get
       reliable numbers, the consensus is that Windows only provides 16
       millisecond resolution in GetProcessTimes (see Python PEP 0418 [1])
    
     * Eliminate terrible hack wherein we would cast between `CTime` and
       `Integer` through `Double`
    
    [1] https://www.python.org/dev/peps/pep-0418/#id59
    
    Test Plan: Validate on various platforms
    
    Reviewers: austin, hvr, erikd
    
    Reviewed By: erikd
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D2001


>---------------------------------------------------------------

cb3456d82eaa8cea6b393273f0c81c57fb760ee5
 libraries/base/System/CPUTime.hsc                  | 148 ++++-----------------
 .../base/System/CPUTime/Posix/ClockGetTime.hsc     |  55 ++++++++
 libraries/base/System/CPUTime/Posix/RUsage.hsc     |  42 ++++++
 libraries/base/System/CPUTime/Posix/Times.hsc      |  39 ++++++
 libraries/base/System/CPUTime/Unsupported.hs       |  20 +++
 libraries/base/System/CPUTime/Utils.hs             |  19 +++
 libraries/base/System/CPUTime/Windows.hsc          |  66 +++++++++
 libraries/base/base.cabal                          |   8 ++
 8 files changed, 276 insertions(+), 121 deletions(-)

Diff suppressed because of size. To see it, use:

    git diff-tree --root --patch-with-stat --no-color --find-copies-harder --ignore-space-at-eol --cc cb3456d82eaa8cea6b393273f0c81c57fb760ee5