Fix race between start and destroy

Before this change, a container starting up could race with
destroy (aka delete) and leave processes behind.

Now, whenever a container is created, Loader.processes gets
a new entry. Start now expects the entry to be there, and if
it's not it means that the container was deleted.

I've also fixed Loader.waitPID to search for the process using
the init process's PID namespace.

We could use a few more tests for signal and wait. I'll send
them in another cl.

PiperOrigin-RevId: 220224290
Change-Id: I15146079f69904dc07d43c3b66cc343a2dab4cc4

1 files changed, 11 insertions, 9 deletions

diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index 96a848197..f884f8c6b 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -37,6 +37,9 @@ const (
 	// ContainerCheckpoint checkpoints a container.
 	ContainerCheckpoint = "containerManager.Checkpoint"
 
+	// ContainerCreate creates a container.
+	ContainerCreate = "containerManager.Create"
+
 	// ContainerDestroy is used to stop a non-root container and free all
 	// associated resources in the sandbox.
 	ContainerDestroy = "containerManager.Destroy"
@@ -175,17 +178,16 @@ func (cm *containerManager) StartRoot(cid *string, _ *struct{}) error {
 	return nil
 }
 
-// ProcessesArgs container arguments to Processes method.
-type ProcessesArgs struct {
-	// CID restricts the result to processes belonging to
-	// the given container. Empty means all.
-	CID string
+// Processes retrieves information about processes running in the sandbox.
+func (cm *containerManager) Processes(cid *string, out *[]*control.Process) error {
+	log.Debugf("containerManager.Processes: %q", *cid)
+	return control.Processes(cm.l.k, *cid, out)
 }
 
-// Processes retrieves information about processes running in the sandbox.
-func (cm *containerManager) Processes(args *ProcessesArgs, out *[]*control.Process) error {
-	log.Debugf("containerManager.Processes")
-	return control.Processes(cm.l.k, args.CID, out)
+// Create creates a container within a sandbox.
+func (cm *containerManager) Create(cid *string, _ *struct{}) error {
+	log.Debugf("containerManager.Create: %q", *cid)
+	return cm.l.createContainer(*cid)
 }
 
 // StartArgs contains arguments to the Start method.