kube play: sdnotify proxy: use a wait group
Use a wait group to a) wait for all proxies in parallel
b) avoid the potential for ABBA deadlocks
[NO NEW TESTS NEEDED] as it is not changing functionality
@@ -11,6 +11,7 @@ import (
"path/filepath"
"strconv"
"strings"
+ "sync"
buildahDefine "github.com/containers/buildah/define"
"github.com/containers/common/libimage"
@@ -699,9 +700,24 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
fmt.Println(playKubePod.ContainerErrors)
}
- // Wait for each proxy to receive a READY message.
- for _, proxy := range sdNotifyProxies {
- if err := proxy.WaitAndClose(); err != nil {
+ // Wait for each proxy to receive a READY message. Use a wait
+ // group to prevent the potential for ABBA kinds of deadlocks.
+ var wg sync.WaitGroup
+ errors := make([]error, len(sdNotifyProxies))
+ for i := range sdNotifyProxies {
+ wg.Add(1)
+ go func(i int) {
+ err := sdNotifyProxies[i].WaitAndClose()
+ if err != nil {
+ err = fmt.Errorf("waiting for sd-notify proxy: %w", err)
+ }
+ errors[i] = err
+ wg.Done()
+ }(i)
+ }
+ wg.Wait()
+ for _, err := range errors {
+ if err != nil {
return nil, err
}
}
