do session crypto work using the worker pool

src/yggdrasil/session.go

@@ -442,6 +442,7 @@ func (sinfo *sessionInfo) recvWorker() {
 	//  Since there's no reason for anywhere else in the session code to need to *read* it...
 	//  Only needs to be updated from the outside if a ping resets it...
 	//  That would get rid of the need to take a mutex for the sessionFunc
+	var callbacks []chan func()
 	doRecv := func(p *wire_trafficPacket) {
 		var bs []byte
 		var err error
@@ -459,7 +460,10 @@ func (sinfo *sessionInfo) recvWorker() {
 			return
 		}
 		var isOK bool
+		ch := make(chan func(), 1)
+		poolFunc := func() {
 			bs, isOK = crypto.BoxOpen(&k, p.Payload, &p.Nonce)
+			callback := func() {
 				if !isOK {
 					util.PutBytes(bs)
 					return
@@ -483,7 +487,24 @@ func (sinfo *sessionInfo) recvWorker() {
 					sinfo.recv <- bs
 				}
 			}
+			ch <- callback
+		}
+		// Send to the worker and wait for it to finish
+		util.WorkerGo(poolFunc)
+		callbacks = append(callbacks, ch)
+	}
 	for {
+		for len(callbacks) > 0 {
+			select {
+			case f := <-callbacks[0]:
+				callbacks = callbacks[1:]
+				f()
+			case <-sinfo.cancel.Finished():
+				return
+			case p := <-sinfo.fromRouter:
+				doRecv(p)
+			}
+		}
 		select {
 		case <-sinfo.cancel.Finished():
 			return
@@ -496,6 +517,7 @@ func (sinfo *sessionInfo) recvWorker() {
 func (sinfo *sessionInfo) sendWorker() {
 	// TODO move info that this worker needs here, send updates via a channel
 	//  Otherwise we need to take a mutex to avoid races with update()
+	var callbacks []chan func()
 	doSend := func(bs []byte) {
 		var p wire_trafficPacket
 		var k crypto.BoxSharedKey
@@ -511,16 +533,34 @@ func (sinfo *sessionInfo) sendWorker() {
 		}
 		// Get the mutex-protected info needed to encrypt the packet
 		sinfo.doFunc(sessionFunc)
+		ch := make(chan func(), 1)
+		poolFunc := func() {
 			// Encrypt the packet
 			p.Payload, _ = crypto.BoxSeal(&k, bs, &p.Nonce)
 			packet := p.encode()
 			// Cleanup
 			util.PutBytes(bs)
 			util.PutBytes(p.Payload)
-		// Send the packet
-		sinfo.core.router.out(packet)
+			// The callback will send the packet
+			callback := func() { sinfo.core.router.out(packet) }
+			ch <- callback
+		}
+		// Send to the worker and wait for it to finish
+		util.WorkerGo(poolFunc)
+		callbacks = append(callbacks, ch)
 	}
 	for {
+		for len(callbacks) > 0 {
+			select {
+			case f := <-callbacks[0]:
+				callbacks = callbacks[1:]
+				f()
+			case <-sinfo.cancel.Finished():
+				return
+			case bs := <-sinfo.send:
+				doSend(bs)
+			}
+		}
 		select {
 		case <-sinfo.cancel.Finished():
 			return