6260: Pull entire status object out of WorkQueue atomically.

[arvados.git] / services / keepstore / handlers.go

diff --git a/services/keepstore/handlers.go b/services/keepstore/handlers.go
index a6665f61640dfdb5f0791b4fc16fc34f084fe4bf..a86bb6a5b552887836e24cb858191bcbe920e479 100644 (file)
--- a/services/keepstore/handlers.go
+++ b/services/keepstore/handlers.go
@@ -192,12 +192,6 @@ type PoolStatus struct {
        Len   int    `json:"BuffersInUse"`
 }
 
-type WorkQueueStatus struct {
-       InProgress  int
-       Outstanding int
-       Queued      int
-}
-
 type NodeStatus struct {
        Volumes    []*VolumeStatus `json:"volumes"`
        BufferPool PoolStatus
@@ -238,22 +232,20 @@ func readNodeStatus(st *NodeStatus) {
        st.BufferPool.Alloc = bufs.Alloc()
        st.BufferPool.Cap = bufs.Cap()
        st.BufferPool.Len = bufs.Len()
-       readWorkQueueStatus(&st.PullQueue, pullq)
-       readWorkQueueStatus(&st.TrashQueue, trashq)
+       st.PullQueue = getWorkQueueStatus(pullq)
+       st.TrashQueue = getWorkQueueStatus(trashq)
        runtime.ReadMemStats(&st.Memory)
 }
 
-// Populate a WorkQueueStatus. This is not atomic, so race conditions
-// can cause InProgress + Queued != Outstanding.
-func readWorkQueueStatus(st *WorkQueueStatus, q *WorkQueue) {
+// return a WorkQueueStatus for the given queue. If q is nil (which
+// should never happen except in test suites), return a zero status
+// value instead of crashing.
+func getWorkQueueStatus(q *WorkQueue) WorkQueueStatus {
        if q == nil {
                // This should only happen during tests.
-               *st = WorkQueueStatus{}
-               return
+               return WorkQueueStatus{}
        }
-       st.InProgress = q.CountInProgress()
-       st.Outstanding = q.CountOutstanding()
-       st.Queued = q.CountQueued()
+       return q.Status()
 }
 
 // DeleteHandler processes DELETE requests.