diff options
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/chan.go | 10 | ||||
| -rw-r--r-- | src/runtime/runtime2.go | 17 |
2 files changed, 18 insertions, 9 deletions
diff --git a/src/runtime/chan.go b/src/runtime/chan.go index cc64d30a68..e89831783e 100644 --- a/src/runtime/chan.go +++ b/src/runtime/chan.go @@ -33,7 +33,10 @@ type hchan struct { recvx uint // receive index recvq waitq // list of recv waiters sendq waitq // list of send waiters - lock mutex + + // lock protects all fields in hchan, as well as several + // fields in sudogs blocked on this channel. + lock mutex } type waitq struct { @@ -261,12 +264,12 @@ func send(c *hchan, sg *sudog, ep unsafe.Pointer, unlockf func()) { c.sendx = c.recvx // c.sendx = (c.sendx+1) % c.dataqsiz } } - unlockf() if sg.elem != nil { sendDirect(c.elemtype, sg, ep) sg.elem = nil } gp := sg.g + unlockf() gp.param = unsafe.Pointer(sg) if sg.releasetime != 0 { sg.releasetime = cputicks() @@ -509,7 +512,6 @@ func recv(c *hchan, sg *sudog, ep unsafe.Pointer, unlockf func()) { if raceenabled { racesync(c, sg) } - unlockf() if ep != nil { // copy data from sender // ep points to our own stack or heap, so nothing @@ -539,10 +541,10 @@ func recv(c *hchan, sg *sudog, ep unsafe.Pointer, unlockf func()) { c.recvx = 0 } c.sendx = c.recvx // c.sendx = (c.sendx+1) % c.dataqsiz - unlockf() } sg.elem = nil gp := sg.g + unlockf() gp.param = unsafe.Pointer(sg) if sg.releasetime != 0 { sg.releasetime = cputicks() diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index 5d7f4354ef..eda258a992 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -214,11 +214,18 @@ type gobuf struct { // Changes here must also be made in src/cmd/compile/internal/gc/select.go's // selecttype. type sudog struct { - 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) + // The following fields are protected by the hchan.lock of the + // channel this sudog is blocking on. + + 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) + + // The following fields are never accessed concurrently. + // waitlink is only accessed by g. + releasetime int64 ticket uint32 waitlink *sudog // g.waiting list |