Data race in internals/overlord/servstate:S.startTestServices(c)

[barrettj12]

This is a utility function called in many of the servstate tests.

pebble/internals/overlord/servstate/manager_test.go

Line 256 in 00bcd1f

func (s *S) startTestServices(c *C) {

It starts two services

• test1: /bin/sh -c "echo test1 | tee -a .../log.txt; sleep 10"
• test2: /bin/sh -c "echo test2 | tee -a .../log.txt; sleep 10"

and then asserts the contents of log.txt are

test1
test2

However, there is a data race, since we may read log.txt before the test2 service has had a chance to write to it.

manager_test.go:203:
    c.Assert(string(data), Matches, "(?s)"+expected)
... value string = "test1\n"
... regex string = "" +
...     "(?s).*test1\n" +
...     ".*test2\n"

To reproduce

Create a new test in internals/overlord/servstate/manager_test.go:

func (s *S) TestStartTestServices(c *C) {
	s.startTestServices(c)
}

Install the stress utility (useful for finding sporadic test failures):

go install golang.org/x/tools/cmd/stress@latest

Run

stress go test ./internals/overlord/servstate -check.f TestStartTestServices -count=1

and start observing failures.

[flotter]

I will add this to #266 - its not included right now, but easy to add.

[flotter]

#266 Should now fix this.