all: speed up tests

Mark tests as parallel where makes sense.
Speed up sys.TransitivelyEnabledCalls.

Execution time is now:

ok  	github.com/google/syzkaller/config		0.172s
ok  	github.com/google/syzkaller/cover		0.060s
ok  	github.com/google/syzkaller/csource		3.081s
ok  	github.com/google/syzkaller/db			0.395s
ok  	github.com/google/syzkaller/executor		0.060s
ok  	github.com/google/syzkaller/fileutil		0.106s
ok  	github.com/google/syzkaller/host		1.530s
ok  	github.com/google/syzkaller/ifuzz		0.491s
ok  	github.com/google/syzkaller/ipc			1.374s
ok  	github.com/google/syzkaller/log			0.014s
ok  	github.com/google/syzkaller/prog		2.604s
ok  	github.com/google/syzkaller/report		0.045s
ok  	github.com/google/syzkaller/symbolizer		0.062s
ok  	github.com/google/syzkaller/sys			0.365s
ok  	github.com/google/syzkaller/syz-dash		0.014s
ok  	github.com/google/syzkaller/syz-hub/state	0.427s
ok  	github.com/google/syzkaller/vm			0.052s

However, main time is still taken by rebuilding sys package.

Fixes #182

csource/csource_test.go

@@ -15,6 +15,7 @@ import (
 )
 
 func initTest(t *testing.T) (rand.Source, int) {
+	t.Parallel()
 	iters := 10
 	if testing.Short() {
 		iters = 1
@@ -70,11 +71,12 @@ func TestSyz(t *testing.T) {
 }
 
 func Test(t *testing.T) {
-	rs, iters := initTest(t)
+	rs, _ := initTest(t)
 	syzProg := prog.GenerateAllSyzProg(rs)
 	t.Logf("syz program:\n%s\n", syzProg.Serialize())
 	for i, opts := range allOptionsPermutations() {
 		t.Run(fmt.Sprintf("%v", i), func(t *testing.T) {
+			rs, iters := initTest(t)
 			t.Logf("opts: %+v", opts)
 			for i := 0; i < iters; i++ {
 				p := prog.Generate(rs, 10, nil)

host/host_test.go

@@ -11,6 +11,7 @@ import (
 )
 
 func TestLog(t *testing.T) {
+	t.Parallel()
 	// Dump for manual inspection.
 	supp, err := DetectSupportedSyscalls()
 	if err != nil {
@@ -40,6 +41,7 @@ func TestLog(t *testing.T) {
 }
 
 func TestSupportedSyscalls(t *testing.T) {
+	t.Parallel()
 	supp, err := DetectSupportedSyscalls()
 	if err != nil {
 		t.Skipf("skipping: %v", err)

ipc/ipc_test.go

@@ -38,6 +38,7 @@ func buildProgram(t *testing.T, src string) string {
 }
 
 func initTest(t *testing.T) (rand.Source, int) {
+	t.Parallel()
 	iters := 100
 	if testing.Short() {
 		iters = 10
@@ -76,11 +77,12 @@ func TestEmptyProg(t *testing.T) {
 }
 
 func TestExecute(t *testing.T) {
+	rs, iters := initTest(t)
+	flags := []uint64{0, FlagThreaded, FlagThreaded | FlagCollide}
+
 	bin := buildExecutor(t)
 	defer os.Remove(bin)
 
-	rs, iters := initTest(t)
-	flags := []uint64{0, FlagThreaded, FlagThreaded | FlagCollide}
 	for _, flag := range flags {
 		t.Logf("testing flags 0x%x\n", flag)
 		cfg := Config{

prog/rand.go

@@ -382,8 +382,6 @@ func (r *randGen) randPageAddr(s *state, typ sys.Type, npages uintptr, data *Arg
 		}
 		starts = append(starts, i)
 	}
-	*poolPtr = starts
-	pageStartPool.Put(poolPtr)
 	var page uintptr
 	if len(starts) != 0 {
 		page = starts[r.rand(len(starts))]
@@ -393,6 +391,8 @@ func (r *randGen) randPageAddr(s *state, typ sys.Type, npages uintptr, data *Arg
 	if !vma {
 		npages = 0
 	}
+	*poolPtr = starts
+	pageStartPool.Put(poolPtr)
 	return pointerArg(typ, page, 0, npages, data)
 }
 

sys/decl.go

@@ -521,14 +521,26 @@ func TransitivelyEnabledCalls(enabled map[*Call]bool) map[*Call]bool {
 	for c := range enabled {
 		supported[c] = true
 	}
+	inputResources := make(map[*Call][]*ResourceType)
+	ctors := make(map[string][]*Call)
+	for c := range supported {
+		inputs := c.InputResources()
+		inputResources[c] = inputs
+		for _, res := range inputs {
+			if _, ok := ctors[res.Desc.Name]; ok {
+				continue
+			}
+			ctors[res.Desc.Name] = resourceCtors(res.Desc.Kind, true)
+		}
+	}
 	for {
 		n := len(supported)
 		haveGettime := supported[CallMap["clock_gettime"]]
 		for c := range supported {
 			canCreate := true
-			for _, res := range c.InputResources() {
+			for _, res := range inputResources[c] {
 				noctors := true
-				for _, ctor := range resourceCtors(res.Desc.Kind, true) {
+				for _, ctor := range ctors[res.Desc.Name] {
 					if supported[ctor] {
 						noctors = false
 						break

sys/decl_test.go

@@ -8,6 +8,7 @@ import (
 )
 
 func TestTransitivelyEnabledCalls(t *testing.T) {
+	t.Parallel()
 	calls := make(map[*Call]bool)
 	for _, c := range Calls {
 		calls[c] = true
@@ -37,6 +38,7 @@ func TestTransitivelyEnabledCalls(t *testing.T) {
 }
 
 func TestClockGettime(t *testing.T) {
+	t.Parallel()
 	calls := make(map[*Call]bool)
 	for _, c := range Calls {
 		calls[c] = true

vm/merger.go

@@ -13,6 +13,7 @@ import (
 type OutputMerger struct {
 	Output chan []byte
 	Err    chan error
+	teeMu  sync.Mutex
 	tee    io.Writer
 	wg     sync.WaitGroup
 }
@@ -42,7 +43,9 @@ func (merger *OutputMerger) Add(name string, r io.ReadCloser) {
 				if pos := bytes.LastIndexByte(pending, '\n'); pos != -1 {
 					out := pending[:pos+1]
 					if merger.tee != nil {
+						merger.teeMu.Lock()
 						merger.tee.Write(out)
+						merger.teeMu.Unlock()
 					}
 					select {
 					case merger.Output <- append([]byte{}, out...):
@@ -56,7 +59,9 @@ func (merger *OutputMerger) Add(name string, r io.ReadCloser) {
 				if len(pending) != 0 {
 					pending = append(pending, '\n')
 					if merger.tee != nil {
+						merger.teeMu.Lock()
 						merger.tee.Write(pending)
+						merger.teeMu.Unlock()
 					}
 					select {
 					case merger.Output <- pending: