From a55b3cc15a6d9bce116a90f33df4bc99d9dd6a10 Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher
Date: Sun, 28 Aug 2022 20:31:27 +0200
Subject: tests/matrix: fix data race in TestConcurrentReadWrite

Fixes https://github.com/golang/go/issues/54715

Output was:

$ go test ./tests/matrix -run TestConcurrentReadWrite -race
test_helpers: warning: testParentDir "/tmp/gocryptfs-test-parent-1026" does not reside on ext4, we will miss failures caused by ino reuse
PASS
PASS
==================
WARNING: DATA RACE
Write at 0x00c00038a0e0 by goroutine 63:
  runtime.racewriterange()
      <autogenerated>:1 +0x29
  internal/poll.(*FD).Pread()
      /usr/local/go/src/internal/poll/fd_unix.go:193 +0x169
  os.(*File).pread()
      /usr/local/go/src/os/file_posix.go:40 +0x335
  os.(*File).ReadAt()
      /usr/local/go/src/os/file.go:136 +0x2de
  github.com/rfjakob/gocryptfs/v2/tests/matrix.TestConcurrentReadWrite.func1()
      /home/jakob/go/src/github.com/rfjakob/gocryptfs/tests/matrix/concurrency_test.go:40 +0x14b

Previous write at 0x00c00038a0e0 by goroutine 61:
  runtime.racewriterange()
      <autogenerated>:1 +0x29
  internal/poll.(*FD).Pread()
      /usr/local/go/src/internal/poll/fd_unix.go:193 +0x169
  os.(*File).pread()
      /usr/local/go/src/os/file_posix.go:40 +0x335
  os.(*File).ReadAt()
      /usr/local/go/src/os/file.go:136 +0x2de
  github.com/rfjakob/gocryptfs/v2/tests/matrix.TestConcurrentReadWrite.func1()
      /home/jakob/go/src/github.com/rfjakob/gocryptfs/tests/matrix/concurrency_test.go:40 +0x14b

Goroutine 63 (running) created at:
  github.com/rfjakob/gocryptfs/v2/tests/matrix.TestConcurrentReadWrite()
      /home/jakob/go/src/github.com/rfjakob/gocryptfs/tests/matrix/concurrency_test.go:34 +0x31d
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1446 +0x216
  testing.(*T).Run.func1()
      /usr/local/go/src/testing/testing.go:1493 +0x47

Goroutine 61 (running) created at:
  github.com/rfjakob/gocryptfs/v2/tests/matrix.TestConcurrentReadWrite()
      /home/jakob/go/src/github.com/rfjakob/gocryptfs/tests/matrix/concurrency_test.go:34 +0x31d
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1446 +0x216
  testing.(*T).Run.func1()
      /usr/local/go/src/testing/testing.go:1493 +0x47
==================
--- FAIL: TestConcurrentReadWrite (0.03s)
    testing.go:1319: race detected during execution of test
FAIL
TestMain: matrix[2] = matrix.testcaseMatrix{plaintextnames:false, openssl:"false", aessiv:false, raw64:false, extraArgs:[]string(nil)} failed
FAIL	github.com/rfjakob/gocryptfs/v2/tests/matrix	0.170s
FAIL
---
 tests/matrix/concurrency_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/matrix/concurrency_test.go b/tests/matrix/concurrency_test.go
index d824316..4f060ab 100644
--- a/tests/matrix/concurrency_test.go
+++ b/tests/matrix/concurrency_test.go
@@ -24,7 +24,6 @@ func TestConcurrentReadWrite(t *testing.T) {
 	} else {
 		f.Close()
 	}
-	buf := make([]byte, 100)
 	content := []byte("1234567890")
 	threads := 10
 	loops := 30
@@ -32,6 +31,7 @@ func TestConcurrentReadWrite(t *testing.T) {
 		// Reader thread
 		wg.Add(1)
 		go func() {
+			buf := make([]byte, 100)
 			fRd, err := os.Open(fn)
 			if err != nil {
 				log.Fatal(err)
-- 
cgit v1.2.3