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| author | Austin Clements <austin@google.com> | 2018-09-19 16:42:13 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2018-09-27 18:04:50 +0000 |
| commit | 06afc8b152bc01e1b4f5dce074bae531dd29a9b9 (patch) | |
| tree | c727d1fe2254110506cb32bd16e5ea9b5c20526b /src/runtime/mgcsweep.go | |
| parent | a6df1cece7f6b62a1e1b09f9027692ac0d5411a1 (diff) | |
| download | go-06afc8b152bc01e1b4f5dce074bae531dd29a9b9.tar.gz go-06afc8b152bc01e1b4f5dce074bae531dd29a9b9.zip | |
runtime: simplify the control flow in sweepone
Ending a loop with a break is confusing. Rewrite the loop so the
default behavior is to loop and then do the "post-loop" work outside
of the loop.
Change-Id: Ie49b4132541dfb5124c31a8163f2c883aa4abc75
Reviewed-on: https://go-review.googlesource.com/138155
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Diffstat (limited to 'src/runtime/mgcsweep.go')
| -rw-r--r-- | src/runtime/mgcsweep.go | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/src/runtime/mgcsweep.go b/src/runtime/mgcsweep.go index ecfdee59f4..5cdede002a 100644 --- a/src/runtime/mgcsweep.go +++ b/src/runtime/mgcsweep.go @@ -88,10 +88,11 @@ func sweepone() uintptr { } atomic.Xadd(&mheap_.sweepers, +1) - npages := ^uintptr(0) + // Find a span to sweep. + var s *mspan sg := mheap_.sweepgen for { - s := mheap_.sweepSpans[1-sg/2%2].pop() + s = mheap_.sweepSpans[1-sg/2%2].pop() if s == nil { atomic.Store(&mheap_.sweepdone, 1) break @@ -106,9 +107,14 @@ func sweepone() uintptr { } continue } - if s.sweepgen != sg-2 || !atomic.Cas(&s.sweepgen, sg-2, sg-1) { - continue + if s.sweepgen == sg-2 && atomic.Cas(&s.sweepgen, sg-2, sg-1) { + break } + } + + // Sweep the span we found. + npages := ^uintptr(0) + if s != nil { npages = s.npages if !s.sweep(false) { // Span is still in-use, so this returned no @@ -116,7 +122,6 @@ func sweepone() uintptr { // move to the swept in-use list. npages = 0 } - break } // Decrement the number of active sweepers and if this is the |