diff options
Diffstat (limited to 'src/runtime/select.go')
| -rw-r--r-- | src/runtime/select.go | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/src/runtime/select.go b/src/runtime/select.go index 6e016acfa0..444427ccb7 100644 --- a/src/runtime/select.go +++ b/src/runtime/select.go @@ -319,6 +319,7 @@ func selectgoImpl(sel *hselect) (uintptr, uint16) { sglist *sudog sgnext *sudog qp unsafe.Pointer + nextp **sudog ) loop: @@ -374,8 +375,9 @@ loop: if gp.waiting != nil { throw("gp.waiting != nil") } - for i := 0; i < int(sel.ncase); i++ { - cas = &scases[pollorder[i]] + nextp = &gp.waiting + for _, casei := range lockorder { + cas = &scases[casei] c = cas.c sg := acquireSudog() sg.g = gp @@ -388,9 +390,10 @@ loop: if t0 != 0 { sg.releasetime = -1 } - sg.waitlink = gp.waiting sg.c = c - gp.waiting = sg + // Construct waiting list in lock order. + *nextp = sg + nextp = &sg.waitlink switch cas.kind { case caseRecv: @@ -413,8 +416,7 @@ loop: // pass 3 - dequeue from unsuccessful chans // otherwise they stack up on quiet channels // record the successful case, if any. - // We singly-linked up the SudoGs in case order, so when - // iterating through the linked list they are in reverse order. + // We singly-linked up the SudoGs in lock order. cas = nil sglist = gp.waiting // Clear all elem before unlinking from gp.waiting. @@ -424,8 +426,9 @@ loop: sg1.c = nil } gp.waiting = nil - for i := int(sel.ncase) - 1; i >= 0; i-- { - k = &scases[pollorder[i]] + + for _, casei := range lockorder { + k = &scases[casei] if sglist.releasetime > 0 { k.releasetime = sglist.releasetime } |