Merge pull request #75 from taskcluster/bug1441482

Bug 1441482 - free up disk space between tasks, not after task claim

main.go

@@ -624,10 +624,18 @@ func RunWorker() (exitCode ExitCode) {
 				return NONCURRENT_DEPLOYMENT_ID
 			}
 		}
-		// make sure at least 5 seconds passes between iterations
-		wait5Seconds := time.NewTimer(time.Second * 5)
+
+		// Ensure there is enough disk space *before* claiming a task
+		err := garbageCollection()
+		if err != nil {
+			panic(err)
+		}
+
 		task := ClaimWork()
 
+		// make sure at least 5 seconds pass between queue.claimWork API calls
+		wait5Seconds := time.NewTimer(time.Second * 5)
+
 		if task != nil {
 			errors := task.Run()
 			if errors.Occurred() {

mounts.go

@@ -308,18 +308,9 @@ func (taskMount *TaskMount) Start() *CommandExecutionError {
 	if taskMount.payloadError != nil {
 		return MalformedPayloadError(taskMount.payloadError)
 	}
-	// Let's perform a garbage collection here before running the task. In
-	// taskcluster-worker this will run in its own thread, and here it only
-	// works as we have a single job running at a time, so we don't need to
-	// worry about concurrency etc. But it is ugly to do it here, but
-	// sufficient for generic worker.
-	err := garbageCollection()
-	if err != nil {
-		panic(err)
-	}
 	// Check if any caches need to be purged. See:
 	//   https://docs.taskcluster.net/reference/core/purge-cache
-	err = taskMount.purgeCaches()
+	err := taskMount.purgeCaches()
 	// Two possible strategies if we can't reach purgecache service:
 	//
 	//   1) be optimistic, assume caches are ok, and don't purge them