diff --git a/integration-cli/docker_cli_external_graphdriver_unix_test.go b/integration-cli/docker_cli_external_graphdriver_unix_test.go index 65814d19da..a794ca742d 100644 --- a/integration-cli/docker_cli_external_graphdriver_unix_test.go +++ b/integration-cli/docker_cli_external_graphdriver_unix_test.go @@ -54,6 +54,10 @@ func (s *DockerExternalGraphdriverSuite) SetUpTest(c *check.C) { s.d = NewDaemon(c) } +func (s *DockerExternalGraphdriverSuite) OnTimeout(c *check.C) { + s.d.DumpStackAndQuit() +} + func (s *DockerExternalGraphdriverSuite) TearDownTest(c *check.C) { s.d.Stop() s.ds.TearDownTest(c) diff --git a/pkg/plugins/plugin_test.go b/pkg/plugins/plugin_test.go new file mode 100644 index 0000000000..ac810565f7 --- /dev/null +++ b/pkg/plugins/plugin_test.go @@ -0,0 +1,37 @@ +package plugins + +import ( + "path/filepath" + "runtime" + "sync" + "testing" + "time" +) + +// regression test for deadlock in handlers +func TestPluginAddHandler(t *testing.T) { + // make a plugin which is pre-activated + p := &Plugin{activateWait: sync.NewCond(&sync.Mutex{})} + p.Manifest = &Manifest{Implements: []string{"bananas"}} + storage.plugins["qwerty"] = p + + testActive(t, p) + Handle("bananas", func(_ string, _ *Client) {}) + testActive(t, p) +} + +func testActive(t *testing.T, p *Plugin) { + done := make(chan struct{}) + go func() { + p.waitActive() + close(done) + }() + + select { + case <-time.After(100 * time.Millisecond): + _, f, l, _ := runtime.Caller(1) + t.Fatalf("%s:%d: deadlock in waitActive", filepath.Base(f), l) + case <-done: + } + +} diff --git a/pkg/plugins/plugins.go b/pkg/plugins/plugins.go index acfb209992..125e6c7d66 100644 --- a/pkg/plugins/plugins.go +++ b/pkg/plugins/plugins.go @@ -70,12 +70,12 @@ type Plugin struct { // Manifest of the plugin (see above) Manifest *Manifest `json:"-"` - // error produced by activation - activateErr error - // specifies if the activation sequence is completed (not if it is successful or not) - activated bool // wait for activation to finish activateWait *sync.Cond + // error produced by activation + activateErr error + // keeps track of callback handlers run against this plugin + handlersRun bool } // BasePath returns the path to which all paths returned by the plugin are relative to. @@ -112,19 +112,51 @@ func NewLocalPlugin(name, addr string) *Plugin { func (p *Plugin) activate() error { p.activateWait.L.Lock() - if p.activated { + + if p.activated() { + p.runHandlers() p.activateWait.L.Unlock() return p.activateErr } p.activateErr = p.activateWithLock() - p.activated = true + p.runHandlers() p.activateWait.L.Unlock() p.activateWait.Broadcast() return p.activateErr } +// runHandlers runs the registered handlers for the implemented plugin types +// This should only be run after activation, and while the activation lock is held. +func (p *Plugin) runHandlers() { + if !p.activated() { + return + } + + handlers.RLock() + if !p.handlersRun { + for _, iface := range p.Manifest.Implements { + hdlrs, handled := handlers.extpointHandlers[iface] + if !handled { + continue + } + for _, handler := range hdlrs { + handler(p.name, p.client) + } + } + p.handlersRun = true + } + handlers.RUnlock() + +} + +// activated returns if the plugin has already been activated. +// This should only be called with the activation lock held +func (p *Plugin) activated() bool { + return p.Manifest != nil +} + func (p *Plugin) activateWithLock() error { c, err := NewClient(p.Addr, p.TLSConfig) if err != nil { @@ -138,24 +170,12 @@ func (p *Plugin) activateWithLock() error { } p.Manifest = m - - handlers.RLock() - for _, iface := range m.Implements { - hdlrs, handled := handlers.extpointHandlers[iface] - if !handled { - continue - } - for _, handler := range hdlrs { - handler(p.name, p.client) - } - } - handlers.RUnlock() return nil } func (p *Plugin) waitActive() error { p.activateWait.L.Lock() - for !p.activated { + for !p.activated() { p.activateWait.Wait() } p.activateWait.L.Unlock() @@ -163,7 +183,7 @@ func (p *Plugin) waitActive() error { } func (p *Plugin) implements(kind string) bool { - if err := p.waitActive(); err != nil { + if p.Manifest == nil { return false } for _, driver := range p.Manifest.Implements { @@ -232,7 +252,7 @@ func Get(name, imp string) (*Plugin, error) { if err != nil { return nil, err } - if pl.implements(imp) { + if err := pl.waitActive(); err == nil && pl.implements(imp) { logrus.Debugf("%s implements: %s", name, imp) return pl, nil } @@ -249,9 +269,17 @@ func Handle(iface string, fn func(string, *Client)) { hdlrs = append(hdlrs, fn) handlers.extpointHandlers[iface] = hdlrs + + storage.Lock() for _, p := range storage.plugins { - p.activated = false + p.activateWait.L.Lock() + if p.activated() && p.implements(iface) { + p.handlersRun = false + } + p.activateWait.L.Unlock() } + storage.Unlock() + handlers.Unlock() } @@ -292,7 +320,7 @@ func GetAll(imp string) ([]*Plugin, error) { logrus.Error(pl.err) continue } - if pl.pl.implements(imp) { + if err := pl.pl.waitActive(); err == nil && pl.pl.implements(imp) { out = append(out, pl.pl) } }