x/net/ipv4: test timeouts in TestPacketConnConcurrentReadWriteUnicast

[gopherbot]

#!watchflakes
post <- pkg == "golang.org/x/net/ipv4" && test == "TestPacketConnConcurrentReadWriteUnicast"

Issue created automatically to collect these failures.

Example (log):

panic: test timed out after 10m0s

testing.(*T).Run(0xc000003a00, {0x5a7edd?, 0x69b6a8?}, 0xc00029e000)
	/tmp/workdir/go/src/testing/testing.go:1487 +0x37a
golang.org/x/net/ipv4_test.TestPacketConnConcurrentReadWriteUnicast(0xc000003a00)
	/tmp/workdir/gopath/src/golang.org/x/net/ipv4/readwrite_test.go:361 +0x3ac
testing.tRunner(0xc000003a00, 0x5b4818)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "golang.org/x/net/ipv4" && test == "TestPacketConnConcurrentReadWriteUnicast"

2022-11-04 20:05 freebsd-amd64-13_0 net@93ec86b4 go@156bf3dd x/net/ipv4.TestPacketConnConcurrentReadWriteUnicast (log)

panic: test timed out after 10m0s

testing.(*T).Run(0xc000003a00, {0x5a7edd?, 0x69b6a8?}, 0xc00029e000)
	/tmp/workdir/go/src/testing/testing.go:1487 +0x37a
golang.org/x/net/ipv4_test.TestPacketConnConcurrentReadWriteUnicast(0xc000003a00)
	/tmp/workdir/gopath/src/golang.org/x/net/ipv4/readwrite_test.go:361 +0x3ac
testing.tRunner(0xc000003a00, 0x5b4818)

— watchflakes

[bcmills]

See previously #51342, #50455, #30899.

[bcmills]

(CC @ianlancetaylor)

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "golang.org/x/net/ipv4" && test == "TestPacketConnConcurrentReadWriteUnicast"

2022-12-13 21:41 dragonfly-amd64-622 net@ad92d3db go@0b8add46 x/net/ipv4.TestPacketConnConcurrentReadWriteUnicast (log)

panic: test timed out after 10m0s
running tests:
	TestPacketConnConcurrentReadWriteUnicast (10m0s)
	TestPacketConnConcurrentReadWriteUnicast/UDP (10m0s)
	TestPacketConnConcurrentReadWriteUnicast/UDP/ToFrom (10m0s)

testing.(*T).Run(0xc0000de820, {0x5b29e2?, 0x6147e5?}, 0xc0000683a0)
	/tmp/workdir/go/src/testing/testing.go:1629 +0x405
golang.org/x/net/ipv4_test.TestPacketConnConcurrentReadWriteUnicast(0xc0000de820)
	/tmp/workdir/gopath/src/golang.org/x/net/ipv4/readwrite_test.go:347 +0x346
testing.tRunner(0xc0000de820, 0x5bf6c8)

— watchflakes