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| author | Daniel Morsing <daniel.morsing@gmail.com> | 2017-08-02 19:01:17 +0100 |
|---|---|---|
| committer | Daniel Morsing <daniel.morsing@gmail.com> | 2017-08-15 19:18:00 +0000 |
| commit | 32b94f13cf35e619a0dae6e1e381adc7e182d283 (patch) | |
| tree | 64d58aca0d055ac7ced3b9a611d5ed36e9980d6c /src/runtime/runtime2.go | |
| parent | 89d74f54168619cf1f36b6868626fbb1237c1deb (diff) | |
| download | go-32b94f13cf35e619a0dae6e1e381adc7e182d283.tar.xz | |
runtime: move selectdone into g
Writing to selectdone on the stack of another goroutine meant a
pretty subtle dance between the select code and the stack copying
code. Instead move the selectdone variable into the g struct.
Change-Id: Id246aaf18077c625adef7ca2d62794afef1bdd1b
Reviewed-on: https://go-review.googlesource.com/53390
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/runtime/runtime2.go')
| -rw-r--r-- | src/runtime/runtime2.go | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index 21b1758af9..e4b4f91b5e 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -272,11 +272,14 @@ type sudog struct { // channel this sudog is blocking on. shrinkstack depends on // this for sudogs involved in channel ops. - g *g - selectdone *uint32 // CAS to 1 to win select race (may point to stack) - next *sudog - prev *sudog - elem unsafe.Pointer // data element (may point to stack) + g *g + + // isSelect indicates g is participating in a select, so + // g.selectDone must be CAS'd to win the wake-up race. + isSelect bool + next *sudog + prev *sudog + elem unsafe.Pointer // data element (may point to stack) // The following fields are never accessed concurrently. // For channels, waitlink is only accessed by g. @@ -367,6 +370,7 @@ type g struct { cgoCtxt []uintptr // cgo traceback context labels unsafe.Pointer // profiler labels timer *timer // cached timer for time.Sleep + selectDone uint32 // are we participating in a select and did someone win the race? // Per-G GC state |