Fix rpc go routine leak

util/socket/pool.go

@@ -0,0 +1,56 @@
+package socket
+
+import (
+	"sync"
+)
+
+type Pool struct {
+	sync.RWMutex
+	pool map[string]*Socket
+}
+
+func (p *Pool) Get(id string) (*Socket, bool) {
+	// attempt to get existing socket
+	p.RLock()
+	socket, ok := p.pool[id]
+	if ok {
+		p.RUnlock()
+		return socket, ok
+	}
+	p.RUnlock()
+
+	// create new socket
+	socket = New(id)
+	// save socket
+	p.Lock()
+	p.pool[id] = socket
+	p.Unlock()
+	// return socket
+	return socket, false
+}
+
+func (p *Pool) Release(s *Socket) {
+	p.Lock()
+	defer p.Unlock()
+
+	// close the socket
+	s.Close()
+	delete(p.pool, s.id)
+}
+
+// Close the pool and delete all the sockets
+func (p *Pool) Close() {
+	p.Lock()
+	defer p.Unlock()
+	for id, sock := range p.pool {
+		sock.Close()
+		delete(p.pool, id)
+	}
+}
+
+// NewPool returns a new socket pool
+func NewPool() *Pool {
+	return &Pool{
+		pool: make(map[string]*Socket),
+	}
+}