fix(scheduler): fix data race (#2085)

* fix(scheduler): data race when pushing new tasks

the problem here is that scheduler can be closed in two ways:
- canceling the context given as argument to scheduler.RunScheduler()
- running scheduler.Shutdown()

because of this shutdown can trigger a data race between calling scheduler.inShutdown()
and actually pushing tasks into the pool workers

solved that by keeping a quit channel and listening on both quit channel and ctx.Done()
and closing the worker chan and scheduler afterwards.

Signed-off-by: Petu Eusebiu <peusebiu@cisco.com>

* refactor(scheduler): refactor into a single shutdown

before this we could stop scheduler either by closing the context
provided to RunScheduler(ctx) or by running Shutdown().

simplify things by getting rid of the external context in RunScheduler().
keep an internal context in the scheduler itself and pass it down to all tasks.

Signed-off-by: Petu Eusebiu <peusebiu@cisco.com>

---------

Signed-off-by: Petu Eusebiu <peusebiu@cisco.com>

pkg/test/common/utils.go

@@ -1,7 +1,6 @@
 package common
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"math/rand"
@@ -62,44 +61,34 @@ func Location(baseURL string, resp *resty.Response) string {
 }
 
 type Controller interface {
-	Init(ctx context.Context) error
-	Run(ctx context.Context) error
+	Init() error
+	Run() error
 	Shutdown()
 	GetPort() int
 }
 
 type ControllerManager struct {
 	controller Controller
-	// used to stop background tasks(goroutines)
-	cancelRoutinesFunc context.CancelFunc
 }
 
-func (cm *ControllerManager) RunServer(ctx context.Context) {
+func (cm *ControllerManager) RunServer() {
 	// Useful to be able to call in the same goroutine for testing purposes
-	if err := cm.controller.Run(ctx); !errors.Is(err, http.ErrServerClosed) {
+	if err := cm.controller.Run(); !errors.Is(err, http.ErrServerClosed) {
 		panic(err)
 	}
 }
 
 func (cm *ControllerManager) StartServer() {
-	ctx, cancel := context.WithCancel(context.Background())
-	cm.cancelRoutinesFunc = cancel
-
-	if err := cm.controller.Init(ctx); err != nil {
+	if err := cm.controller.Init(); err != nil {
 		panic(err)
 	}
 
 	go func() {
-		cm.RunServer(ctx)
+		cm.RunServer()
 	}()
 }
 
 func (cm *ControllerManager) StopServer() {
-	// stop background tasks
-	if cm.cancelRoutinesFunc != nil {
-		cm.cancelRoutinesFunc()
-	}
-
 	cm.controller.Shutdown()
 }
 

pkg/test/common/utils_test.go

@@ -1,7 +1,6 @@
 package common_test
 
 import (
-	"context"
 	"os"
 	"path"
 	"testing"
@@ -53,11 +52,9 @@ func TestControllerManager(t *testing.T) {
 		ctlr := api.NewController(conf)
 		ctlrManager := tcommon.NewControllerManager(ctlr)
 
-		ctx := context.Background()
-
-		err := ctlr.Init(ctx)
+		err := ctlr.Init()
 		So(err, ShouldBeNil)
 
-		So(func() { ctlrManager.RunServer(ctx) }, ShouldPanic)
+		So(func() { ctlrManager.RunServer() }, ShouldPanic)
 	})
 }