Merge pull request #351 from libp2p/fix/hanging-provide

Add timeout

Author: Stebalien

lookup.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"strings"
+	"time"
 
 	"github.com/libp2p/go-libp2p-core/peer"
 
@@ -93,8 +94,10 @@ func (dht *IpfsDHT) GetClosestPeers(ctx context.Context, key string) (<-chan pee
 	go func() {
 		defer close(out)
 		defer e.Done()
+		timedCtx, cancel := context.WithTimeout(ctx, time.Minute)
+		defer cancel()
 		// run it!
-		res, err := query.Run(ctx, tablepeers)
+		res, err := query.Run(timedCtx, tablepeers)
 		if err != nil {
 			logger.Debugf("closestPeers query run error: %s", err)
 		}

routing.go

@@ -408,7 +408,28 @@ func (dht *IpfsDHT) Provide(ctx context.Context, key cid.Cid, brdcst bool) (err
 		return nil
 	}
 
-	peers, err := dht.GetClosestPeers(ctx, key.KeyString())
+	closerCtx := ctx
+	if deadline, ok := ctx.Deadline(); ok {
+		now := time.Now()
+		timeout := deadline.Sub(now)
+
+		if timeout < 0 {
+			// timed out
+			return context.DeadlineExceeded
+		} else if timeout < 10*time.Second {
+			// Reserve 10% for the final put.
+			deadline = deadline.Add(timeout / 10)
+		} else {
+			// Otherwise, reserve a second (we'll already be
+			// connected so this should be fast).
+			deadline = deadline.Add(-time.Second)
+		}
+		var cancel context.CancelFunc
+		closerCtx, cancel = context.WithDeadline(ctx, deadline)
+		defer cancel()
+	}
+
+	peers, err := dht.GetClosestPeers(closerCtx, key.KeyString())
 	if err != nil {
 		return err
 	}