fstest/test_all: add oneonly flag to only run one test per backend if required

fstest/test_all/config.go

@@ -28,6 +28,7 @@ type Backend struct {
 	Remote   string // name of the test remote
 	SubDir   bool   // set to test with -sub-dir
 	FastList bool   // set to test with -fast-list
+	OneOnly  bool   // set to run only one backend test at once
 }
 
 // MakeRuns creates Run objects the Backend and Test
@@ -52,6 +53,7 @@ func (b *Backend) MakeRuns(t *Test) (runs []*Run) {
 				SubDir:    subdir,
 				FastList:  fastlist,
 				NoRetries: t.NoRetries,
+				OneOnly:   b.OneOnly,
 			}
 			if t.AddBackend {
 				run.Path = path.Join(run.Path, b.Backend)

fstest/test_all/config.yaml

@@ -77,6 +77,7 @@ backends:
    remote:   "TestQingStor:"
    subdir:   false
    fastlist: false
+   oneonly:  true
  - backend:  "azureblob"
    remote:   "TestAzureBlob:"
    subdir:   true

fstest/test_all/run.go

@@ -14,6 +14,7 @@ import (
 	"regexp"
 	"runtime"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/ncw/rclone/fs"
@@ -21,6 +22,12 @@ import (
 
 const testBase = "github.com/ncw/rclone/"
 
+// Control concurrency per backend if required
+var (
+	oneOnlyMu sync.Mutex
+	oneOnly   = map[string]*sync.Mutex{}
+)
+
 // Run holds info about a running test
 //
 // A run just runs one command line, but it can be run multiple times
@@ -33,6 +40,7 @@ type Run struct {
 	SubDir    bool   // add -sub-dir to tests
 	FastList  bool   // add -fast-list to tests
 	NoRetries bool   // don't retry if set
+	OneOnly   bool   // only run test for this backend at once
 	// Internals
 	cmdLine     []string
 	cmdString   string
@@ -300,6 +308,17 @@ func (r *Run) FailedTests() string {
 
 // Run runs all the trials for this test
 func (r *Run) Run(logDir string, result chan<- *Run) {
+	if r.OneOnly {
+		oneOnlyMu.Lock()
+		mu := oneOnly[r.Backend]
+		if mu == nil {
+			mu = new(sync.Mutex)
+			oneOnly[r.Backend] = mu
+		}
+		oneOnlyMu.Unlock()
+		mu.Lock()
+		defer mu.Unlock()
+	}
 	r.Init()
 	r.logDir = logDir
 	for r.try = 1; r.try <= *maxTries; r.try++ {