21227: Fix copied mutex after first use.

[arvados.git] / sdk / go / arvados / client.go

diff --git a/sdk/go/arvados/client.go b/sdk/go/arvados/client.go
index 735a44d24c9263d3248fd5c9ae2b0574ca15ca22..172763fe8065dda88f37ab9ffb011244f2a61d3a 100644 (file)
--- a/sdk/go/arvados/client.go
+++ b/sdk/go/arvados/client.go
@@ -88,7 +88,10 @@ type Client struct {
        // differs from an outgoing connection limit (a feature
        // provided by http.Transport) when concurrent calls are
        // multiplexed on a single http2 connection.
-       requestLimiter requestLimiter
+       //
+       // getRequestLimiter() should always be used, because this can
+       // be nil.
+       requestLimiter *requestLimiter
 
        last503 atomic.Value
 }
@@ -150,7 +153,7 @@ func NewClientFromConfig(cluster *Cluster) (*Client, error) {
                APIHost:        ctrlURL.Host,
                Insecure:       cluster.TLS.Insecure,
                Timeout:        5 * time.Minute,
-               requestLimiter: requestLimiter{maxlimit: int64(cluster.API.MaxConcurrentRequests / 4)},
+               requestLimiter: &requestLimiter{maxlimit: int64(cluster.API.MaxConcurrentRequests / 4)},
        }, nil
 }
 
@@ -287,7 +290,7 @@ func (c *Client) Do(req *http.Request) (*http.Response, error) {
                rclient.RetryMax = 0
        }
        rclient.CheckRetry = func(ctx context.Context, resp *http.Response, respErr error) (bool, error) {
-               if c.requestLimiter.Report(resp, respErr) {
+               if c.getRequestLimiter().Report(resp, respErr) {
                        c.last503.Store(time.Now())
                }
                if c.Timeout == 0 {
@@ -314,9 +317,10 @@ func (c *Client) Do(req *http.Request) (*http.Response, error) {
        }
        rclient.Logger = nil
 
-       c.requestLimiter.Acquire(ctx)
+       limiter := c.getRequestLimiter()
+       limiter.Acquire(ctx)
        if ctx.Err() != nil {
-               c.requestLimiter.Release()
+               limiter.Release()
                cancel()
                return nil, ctx.Err()
        }
@@ -328,7 +332,7 @@ func (c *Client) Do(req *http.Request) (*http.Response, error) {
                }
        }
        if err != nil {
-               c.requestLimiter.Release()
+               limiter.Release()
                cancel()
                return nil, err
        }
@@ -338,7 +342,7 @@ func (c *Client) Do(req *http.Request) (*http.Response, error) {
        resp.Body = cancelOnClose{
                ReadCloser: resp.Body,
                cancel: func() {
-                       c.requestLimiter.Release()
+                       limiter.Release()
                        cancel()
                },
        }
@@ -352,6 +356,19 @@ func (c *Client) Last503() time.Time {
        return t
 }
 
+// globalRequestLimiter doesn't have a maximum number of outgoing
+// connections, but is just used to backoff after 503 errors.
+var globalRequestLimiter requestLimiter
+
+// Get this client's requestLimiter, or the global requestLimiter
+// singleton if the client doesn't have its own.
+func (c *Client) getRequestLimiter() *requestLimiter {
+       if c.requestLimiter != nil {
+               return c.requestLimiter
+       }
+       return &globalRequestLimiter
+}
+
 // cancelOnClose calls a provided CancelFunc when its wrapped
 // ReadCloser's Close() method is called.
 type cancelOnClose struct {