diff options
author | Matthew Holt <mholt@users.noreply.github.com> | 2019-04-02 15:31:02 -0600 |
---|---|---|
committer | Matthew Holt <mholt@users.noreply.github.com> | 2019-04-02 15:31:02 -0600 |
commit | 59a5d0db28e36b9732bc9ad2b73bcde9188e207c (patch) | |
tree | a003061dd272d1cc216318c9cf295a771de63df4 | |
parent | f976aa744385b097239a7323af4dec11f83bc949 (diff) |
Close listeners which are no longer used
-rw-r--r-- | caddy.go | 17 | ||||
-rw-r--r-- | listeners.go | 35 |
2 files changed, 40 insertions, 12 deletions
@@ -6,6 +6,7 @@ import ( "log" "strings" "sync" + "sync/atomic" "time" ) @@ -24,6 +25,7 @@ func Start(cfg Config) error { cfg.runners[modName] = val.(Runner) } + // start the new runners for name, r := range cfg.runners { err := r.Run() if err != nil { @@ -32,6 +34,7 @@ func Start(cfg Config) error { } } + // shut down down the old ones currentCfgMu.Lock() if currentCfg != nil { for _, r := range currentCfg.runners { @@ -44,6 +47,20 @@ func Start(cfg Config) error { currentCfg = &cfg currentCfgMu.Unlock() + // shut down listeners that are no longer being used + listenersMu.Lock() + for key, info := range listeners { + if atomic.LoadInt32(&info.usage) == 0 { + err := info.ln.Close() + if err != nil { + log.Printf("[ERROR] closing listener %s: %v", info.ln.Addr(), err) + continue + } + delete(listeners, key) + } + } + listenersMu.Unlock() + return nil } diff --git a/listeners.go b/listeners.go index 6849319..7102e76 100644 --- a/listeners.go +++ b/listeners.go @@ -15,9 +15,10 @@ func Listen(network, addr string) (net.Listener, error) { listenersMu.Lock() defer listenersMu.Unlock() - // if listener already exists, return it - if ln, ok := listeners[lnKey]; ok { - return &fakeCloseListener{Listener: ln}, nil + // if listener already exists, increment usage counter, then return listener + if lnInfo, ok := listeners[lnKey]; ok { + atomic.AddInt32(&lnInfo.usage, 1) + return &fakeCloseListener{usage: &lnInfo.usage, Listener: lnInfo.ln}, nil } // or, create new one and save it @@ -25,9 +26,12 @@ func Listen(network, addr string) (net.Listener, error) { if err != nil { return nil, err } - listeners[lnKey] = ln - return &fakeCloseListener{Listener: ln}, nil + // make sure to start its usage counter at 1 + lnInfo := &listenerUsage{usage: 1, ln: ln} + listeners[lnKey] = lnInfo + + return &fakeCloseListener{usage: &lnInfo.usage, Listener: ln}, nil } // fakeCloseListener's Close() method is a no-op. This allows @@ -36,7 +40,8 @@ func Listen(network, addr string) (net.Listener, error) { // listener remains running. Listeners should be re-wrapped in // a new fakeCloseListener each time the listener is reused. type fakeCloseListener struct { - closed int32 + closed int32 // accessed atomically + usage *int32 // accessed atomically net.Listener } @@ -92,16 +97,15 @@ func (fcl *fakeCloseListener) Close() error { case *net.UnixListener: ln.SetDeadline(time.Now().Add(-1 * time.Minute)) } + + // since we're no longer using this listener, + // decrement the usage counter + atomic.AddInt32(fcl.usage, -1) } return nil } -// CloseUnderlying actually closes the underlying listener. -func (fcl *fakeCloseListener) CloseUnderlying() error { - return fcl.Listener.Close() -} - func (fcl *fakeCloseListener) fakeClosedErr() error { return &net.OpError{ Op: "accept", @@ -118,7 +122,14 @@ func (fcl *fakeCloseListener) fakeClosedErr() error { // socket is actually left open. var ErrFakeClosed = fmt.Errorf("listener 'closed' 😉") +// listenerUsage pairs a net.Listener with a +// count of how many servers are using it. +type listenerUsage struct { + usage int32 // accessed atomically + ln net.Listener +} + var ( - listeners = make(map[string]net.Listener) + listeners = make(map[string]*listenerUsage) listenersMu sync.Mutex ) |