archiver: tests: fix several timing nits

Once we've signaled a cond var, it may take some small amount of time for
the goroutines released to hit the spot we're wanting them to be at. Give
them an appropriate amount of time.

services/archiver/archiver_test.go

@@ -37,6 +37,21 @@ func allComplete(inFlight []*ArchiveRequest) bool {
 	return true
 }
 
+func waitForCount(t *testing.T, num int) {
+	var numQueued int
+
+	// Wait for 3 seconds to hit the queue.
+	timeout := time.Now().Add(3 * time.Second)
+	for {
+		numQueued = len(archiveInProgress)
+		if numQueued == num || time.Now().After(timeout) {
+			break
+		}
+	}
+
+	assert.Equal(t, num, len(archiveInProgress))
+}
+
 func releaseOneEntry(t *testing.T, inFlight []*ArchiveRequest) {
 	var nowQueued, numQueued int
 
@@ -58,7 +73,7 @@ func releaseOneEntry(t *testing.T, inFlight []*ArchiveRequest) {
 	assert.NotEqual(t, nowQueued, numQueued)
 
 	// Also make sure that we released only one.
-	assert.Equal(t, nowQueued, numQueued+1)
+	assert.Equal(t, nowQueued, numQueued-1)
 }
 
 func TestArchive_Basic(t *testing.T) {
@@ -106,16 +121,20 @@ func TestArchive_Basic(t *testing.T) {
 	inFlight[2] = secondReq
 
 	ArchiveRepository(zipReq)
-	assert.Equal(t, len(archiveInProgress), 1)
+	waitForCount(t, 1)
 	ArchiveRepository(tgzReq)
-	assert.Equal(t, len(archiveInProgress), 2)
+	waitForCount(t, 2)
 	ArchiveRepository(secondReq)
-	assert.Equal(t, len(archiveInProgress), 3)
+	waitForCount(t, 3)
 
 	// Make sure sending an unprocessed request through doesn't affect the queue
 	// count.
 	ArchiveRepository(zipReq)
-	assert.Equal(t, len(archiveInProgress), 3)
+
+	// Sleep two seconds to make sure the queue doesn't change.
+	two_seconds, _ := time.ParseDuration("2s")
+	time.Sleep(two_seconds)
+	assert.Equal(t, 3, len(archiveInProgress))
 
 	// Release them all, they'll then stall at the archiveQueueReleaseCond while
 	// we examine the queue state.