rpc: avoid panic during request after WS connection is closed

Fix the following panic:
```
panic: assignment to entry in nil map

goroutine 131 [running]:
github.com/nspcc-dev/neo-go/pkg/rpc/client.(*WSClient).registerRespChannel(0xc00033c240, 0x0, 0xc00003e2a0)
        /home/denis/go/pkg/mod/github.com/nspcc-dev/neo-go@v0.98.2/pkg/rpc/client/wsclient.go:244 +0x96
github.com/nspcc-dev/neo-go/pkg/rpc/client.(*WSClient).makeWsRequest(0xc00033c240, 0xc002080000)
        /home/denis/go/pkg/mod/github.com/nspcc-dev/neo-go@v0.98.2/pkg/rpc/client/wsclient.go:264 +0x69
github.com/nspcc-dev/neo-go/pkg/rpc/client.(*Client).performRequest(0xc00033c240, {0xc9f173, 0xd}, {{0x13d09d0, 0x0, 0x0}}, {0xb44120, 0xc00147a000})
        /home/denis/go/pkg/mod/github.com/nspcc-dev/neo-go@v0.98.2/pkg/rpc/client/client.go:186 +0x15d
github.com/nspcc-dev/neo-go/pkg/rpc/client.(*Client).GetBlockCount(0xc001fb5440)
        /home/denis/go/pkg/mod/github.com/nspcc-dev/neo-go@v0.98.2/pkg/rpc/client/rpc.go:73 +0x69
...
```
This commit is contained in:
Anna Shaleva 2022-04-26 17:19:51 +03:00 committed by Roman Khimov
parent a7fe85a2d8
commit b1f74b549d
2 changed files with 24 additions and 8 deletions

View file

@ -243,12 +243,6 @@ func (c *WSClient) wsWriter() {
}
}
func (c *WSClient) registerRespChannel(id uint64, ch chan *response.Raw) {
c.respLock.Lock()
defer c.respLock.Unlock()
c.respChannels[id] = ch
}
func (c *WSClient) unregisterRespChannel(id uint64) {
c.respLock.Lock()
defer c.respLock.Unlock()
@ -266,8 +260,15 @@ func (c *WSClient) getResponseChannel(id uint64) chan *response.Raw {
func (c *WSClient) makeWsRequest(r *request.Raw) (*response.Raw, error) {
ch := make(chan *response.Raw)
c.registerRespChannel(r.ID, ch)
c.respLock.Lock()
select {
case <-c.done:
c.respLock.Unlock()
return nil, errors.New("connection lost before registering response channel")
default:
c.respChannels[r.ID] = ch
c.respLock.Unlock()
}
select {
case <-c.done:
return nil, errors.New("connection lost before sending the request")

View file

@ -453,3 +453,18 @@ func TestWSDoubleClose(t *testing.T) {
c.Close()
})
}
func TestWS_RequestAfterClose(t *testing.T) {
srv := initTestServer(t, "")
c, err := NewWS(context.TODO(), httpURLtoWS(srv.URL), Options{})
require.NoError(t, err)
c.Close()
require.NotPanics(t, func() {
_, err = c.GetBlockCount()
})
require.Error(t, err)
require.True(t, strings.Contains(err.Error(), "connection lost before registering response channel"))
}