diff options
Diffstat (limited to 'src/runtime/select.go')
| -rw-r--r-- | src/runtime/select.go | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/src/runtime/select.go b/src/runtime/select.go index a069e3e050..081db7bad4 100644 --- a/src/runtime/select.go +++ b/src/runtime/select.go @@ -221,12 +221,12 @@ func selectgo(cas0 *scase, order0 *uint16, ncases int) (int, bool) { nextp **sudog ) -loop: // pass 1 - look for something already waiting var dfli int var dfl *scase var casi int var cas *scase + var caseSuccess bool var recvOK bool for i := 0; i < ncases; i++ { casi = int(pollorder[i]) @@ -331,6 +331,7 @@ loop: // We singly-linked up the SudoGs in lock order. casi = -1 cas = nil + caseSuccess = false sglist = gp.waiting // Clear all elem before unlinking from gp.waiting. for sg1 := gp.waiting; sg1 != nil; sg1 = sg1.waitlink { @@ -352,6 +353,7 @@ loop: // sg has already been dequeued by the G that woke us up. casi = int(casei) cas = k + caseSuccess = sglist.success } else { c = k.c if k.kind == caseSend { @@ -367,16 +369,7 @@ loop: } if cas == nil { - // We can wake up with gp.param == nil (so cas == nil) - // when a channel involved in the select has been closed. - // It is easiest to loop and re-run the operation; - // we'll see that it's now closed. - // Maybe some day we can signal the close explicitly, - // but we'd have to distinguish close-on-reader from close-on-writer. - // It's easiest not to duplicate the code and just recheck above. - // We know that something closed, and things never un-close, - // so we won't block again. - goto loop + throw("selectgo: bad wakeup") } c = cas.c @@ -386,7 +379,9 @@ loop: } if cas.kind == caseRecv { - recvOK = true + recvOK = caseSuccess + } else if cas.kind == caseSend && !caseSuccess { + goto sclose } if raceenabled { |