Change Handler interface to take context.Context

background.go

@@ -5,6 +5,7 @@
 package asynq
 
 import (
+	"context"
 	"fmt"
 	"math"
 	"math/rand"
@@ -141,18 +142,18 @@ func NewBackground(r RedisConnOpt, cfg *Config) *Background {
 // If ProcessTask return a non-nil error or panics, the task
 // will be retried after delay.
 type Handler interface {
-	ProcessTask(*Task) error
+	ProcessTask(context.Context, *Task) error
 }
 
 // The HandlerFunc type is an adapter to allow the use of
 // ordinary functions as a Handler. If f is a function
 // with the appropriate signature, HandlerFunc(f) is a
 // Handler that calls f.
-type HandlerFunc func(*Task) error
+type HandlerFunc func(context.Context, *Task) error
 
-// ProcessTask calls fn(task)
-func (fn HandlerFunc) ProcessTask(task *Task) error {
-	return fn(task)
+// ProcessTask calls fn(ctx, task)
+func (fn HandlerFunc) ProcessTask(ctx context.Context, task *Task) error {
+	return fn(ctx, task)
 }
 
 // Run starts the background-task processing and blocks until

background_test.go

@@ -5,6 +5,7 @@
 package asynq
 
 import (
+	"context"
 	"testing"
 	"time"
 
@@ -27,7 +28,7 @@ func TestBackground(t *testing.T) {
 	})
 
 	// no-op handler
-	h := func(task *Task) error {
+	h := func(ctx context.Context, task *Task) error {
 		return nil
 	}
 

benchmark_test.go

@@ -5,6 +5,7 @@
 package asynq
 
 import (
+	"context"
 	"fmt"
 	"math/rand"
 	"sync"
@@ -37,7 +38,7 @@ func BenchmarkEndToEndSimple(b *testing.B) {
 
 		var wg sync.WaitGroup
 		wg.Add(count)
-		handler := func(t *Task) error {
+		handler := func(ctx context.Context, t *Task) error {
 			wg.Done()
 			return nil
 		}
@@ -82,7 +83,7 @@ func BenchmarkEndToEnd(b *testing.B) {
 
 		var wg sync.WaitGroup
 		wg.Add(count * 2)
-		handler := func(t *Task) error {
+		handler := func(ctx context.Context, t *Task) error {
 			// randomly fail 1% of tasks
 			if rand.Intn(100) == 1 {
 				return fmt.Errorf(":(")
@@ -141,7 +142,7 @@ func BenchmarkEndToEndMultipleQueues(b *testing.B) {
 
 		var wg sync.WaitGroup
 		wg.Add(highCount + defaultCount + lowCount)
-		handler := func(t *Task) error {
+		handler := func(ctx context.Context, t *Task) error {
 			wg.Done()
 			return nil
 		}

processor.go

@@ -5,6 +5,7 @@
 package asynq
 
 import (
+	"context"
 	"fmt"
 	"math/rand"
 	"sort"
@@ -73,7 +74,7 @@ func newProcessor(r *rdb.RDB, pinfo *base.ProcessInfo, fn retryDelayFunc, syncRe
 		done:           make(chan struct{}),
 		abort:          make(chan struct{}),
 		quit:           make(chan struct{}),
-		handler:        HandlerFunc(func(t *Task) error { return fmt.Errorf("handler not set") }),
+		handler:        HandlerFunc(func(ctx context.Context, t *Task) error { return fmt.Errorf("handler not set") }),
 	}
 }
 
@@ -160,8 +161,10 @@ func (p *processor) exec() {
 
 			resCh := make(chan error, 1)
 			task := NewTask(msg.Type, msg.Payload)
+			// TODO: Set timeout if provided
+			ctx := context.Background()
 			go func() {
-				resCh <- perform(p.handler, task)
+				resCh <- perform(ctx, task, p.handler)
 			}()
 
 			select {
@@ -282,13 +285,13 @@ func (p *processor) queues() []string {
 // perform calls the handler with the given task.
 // If the call returns without panic, it simply returns the value,
 // otherwise, it recovers from panic and returns an error.
-func perform(h Handler, task *Task) (err error) {
+func perform(ctx context.Context, task *Task, h Handler) (err error) {
 	defer func() {
 		if x := recover(); x != nil {
 			err = fmt.Errorf("panic: %v", x)
 		}
 	}()
-	return h.ProcessTask(task)
+	return h.ProcessTask(ctx, task)
 }
 
 // uniq dedupes elements and returns a slice of unique names of length l.

processor_test.go

@@ -5,6 +5,7 @@
 package asynq
 
 import (
+	"context"
 	"fmt"
 	"sort"
 	"sync"
@@ -59,7 +60,7 @@ func TestProcessorSuccess(t *testing.T) {
 		// instantiate a new processor
 		var mu sync.Mutex
 		var processed []*Task
-		handler := func(task *Task) error {
+		handler := func(ctx context.Context, task *Task) error {
 			mu.Lock()
 			defer mu.Unlock()
 			processed = append(processed, task)
@@ -146,7 +147,7 @@ func TestProcessorRetry(t *testing.T) {
 		delayFunc := func(n int, e error, t *Task) time.Duration {
 			return tc.delay
 		}
-		handler := func(task *Task) error {
+		handler := func(ctx context.Context, task *Task) error {
 			return fmt.Errorf(errMsg)
 		}
 		pi := base.NewProcessInfo("localhost", 1234, 10, defaultQueueConfig, false)
@@ -264,7 +265,7 @@ func TestProcessorWithStrictPriority(t *testing.T) {
 		// instantiate a new processor
 		var mu sync.Mutex
 		var processed []*Task
-		handler := func(task *Task) error {
+		handler := func(ctx context.Context, task *Task) error {
 			mu.Lock()
 			defer mu.Unlock()
 			processed = append(processed, task)
@@ -303,7 +304,7 @@ func TestPerform(t *testing.T) {
 	}{
 		{
 			desc: "handler returns nil",
-			handler: func(t *Task) error {
+			handler: func(ctx context.Context, t *Task) error {
 				return nil
 			},
 			task:    NewTask("gen_thumbnail", map[string]interface{}{"src": "some/img/path"}),
@@ -311,7 +312,7 @@ func TestPerform(t *testing.T) {
 		},
 		{
 			desc: "handler returns error",
-			handler: func(t *Task) error {
+			handler: func(ctx context.Context, t *Task) error {
 				return fmt.Errorf("something went wrong")
 			},
 			task:    NewTask("gen_thumbnail", map[string]interface{}{"src": "some/img/path"}),
@@ -319,7 +320,7 @@ func TestPerform(t *testing.T) {
 		},
 		{
 			desc: "handler panics",
-			handler: func(t *Task) error {
+			handler: func(ctx context.Context, t *Task) error {
 				panic("something went terribly wrong")
 			},
 			task:    NewTask("gen_thumbnail", map[string]interface{}{"src": "some/img/path"}),
@@ -328,7 +329,7 @@ func TestPerform(t *testing.T) {
 	}
 
 	for _, tc := range tests {
-		got := perform(tc.handler, tc.task)
+		got := perform(context.Background(), tc.task, tc.handler)
 		if !tc.wantErr && got != nil {
 			t.Errorf("%s: perform() = %v, want nil", tc.desc, got)
 			continue