diff options
Diffstat (limited to 'pkg/flipcall/ctrl_futex.go')
| -rw-r--r-- | pkg/flipcall/ctrl_futex.go | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/pkg/flipcall/ctrl_futex.go b/pkg/flipcall/ctrl_futex.go index 865b6f640..8390915a2 100644 --- a/pkg/flipcall/ctrl_futex.go +++ b/pkg/flipcall/ctrl_futex.go @@ -82,6 +82,7 @@ func (ep *Endpoint) ctrlWaitFirst() error { *ep.dataLen() = w.Len() // Return control to the client. + raceBecomeInactive() if err := ep.futexSwitchToPeer(); err != nil { return err } @@ -121,7 +122,16 @@ func (ep *Endpoint) enterFutexWait() error { } func (ep *Endpoint) exitFutexWait() { - atomic.AddInt32(&ep.ctrl.state, -epsBlocked) + switch eps := atomic.AddInt32(&ep.ctrl.state, -epsBlocked); eps { + case 0: + return + case epsShutdown: + // ep.ctrlShutdown() was called while we were blocked, so we are + // repsonsible for indicating connection shutdown. + ep.shutdownConn() + default: + panic(fmt.Sprintf("invalid flipcall.Endpoint.ctrl.state after flipcall.Endpoint.exitFutexWait(): %v", eps+epsBlocked)) + } } func (ep *Endpoint) ctrlShutdown() { @@ -142,5 +152,25 @@ func (ep *Endpoint) ctrlShutdown() { break } } + } else { + // There is no blocked thread, so we are responsible for indicating + // connection shutdown. + ep.shutdownConn() + } +} + +func (ep *Endpoint) shutdownConn() { + switch cs := atomic.SwapUint32(ep.connState(), csShutdown); cs { + case ep.activeState: + if err := ep.futexWakeConnState(1); err != nil { + log.Warningf("failed to FUTEX_WAKE peer Endpoint for shutdown: %v", err) + } + case ep.inactiveState: + // The peer is currently active and will detect shutdown when it tries + // to update the connection state. + case csShutdown: + // The peer also called Endpoint.Shutdown(). + default: + log.Warningf("unexpected connection state before Endpoint.shutdownConn(): %v", cs) } } |