The block-write and block-read tests are both flaky,
because each assumes it can get a normal read/write
completed within 10ms. This isn’t always true.
We can’t increase the timeouts, because that slows down the test.
However, we don’t need to issue a regular read/write for this test.
The immediately preceding tests already test this code,
using a far more generous timeout.
Remove the extraneous read/write.
This drops the failure rate from 1 per 20,000 to undetectable
on my machine.
While we’re here, fix a typo in a debug print statement.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Windows has a low resolution timer.
Some of the tests assumed that unblock takes effect immediately.
Consider:
t := time.Now()
elapsed := time.Now().After(t)
It seems plausible that elapsed should always be true.
However, with a low resolution timer, that might fail.
Change time.Now().After to !time.Now().Before,
so that unblocking always takes effect immediately.
Fixes#873.
This is a lot like wiring up a local UDP socket, read and write
deadlines work. The big difference is the Block feature, which
lets you stop the packet flow without breaking the connection.
This lets you emulate broken sockets and test timeouts actually
work.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
