diff options
author | Austin Clements <austin@google.com> | 2019-06-26 14:35:05 -0400 |
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committer | Austin Clements <austin@google.com> | 2019-06-26 19:48:42 +0000 |
commit | 9caaac2c92f866383b52fca544b9871acf5fda1c (patch) | |
tree | c8fb0d74fe8cbf1f2d0c05c384f3fe79058a087a /src/sync | |
parent | c19b3a60da360a4e02b18dcb3430ec3485a0a831 (diff) | |
download | go-git-9caaac2c92f866383b52fca544b9871acf5fda1c.tar.gz |
sync: only check for successful PopHeads in long mode
In TestPoolDequeue it's surprisingly common for the queue to stay
nearly empty the whole time and for a racing PopTail to happen in the
window between the producer doing a PushHead and doing a PopHead. In
short mode, there are only 100 PopTail attempts. On linux/amd64, it's
not uncommon for this to fail 50% of the time. On linux/arm64, it's
not uncommon for this to fail 100% of the time, causing the test to
fail.
This CL fixes this by only checking for a successful PopTail in long
mode. Long mode makes 200,000 PopTail attempts, and has never been
observed to fail.
Fixes #31422.
Change-Id: If464d55eb94fcb0b8d78fbc441d35be9f056a290
Reviewed-on: https://go-review.googlesource.com/c/go/+/183981
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Diffstat (limited to 'src/sync')
-rw-r--r-- | src/sync/pool_test.go | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/sync/pool_test.go b/src/sync/pool_test.go index 814c4a6812..ad98350b2b 100644 --- a/src/sync/pool_test.go +++ b/src/sync/pool_test.go @@ -236,10 +236,12 @@ func testPoolDequeue(t *testing.T, d PoolDequeue) { t.Errorf("expected have[%d] = 1, got %d", i, count) } } - if nPopHead == 0 { - // In theory it's possible in a valid schedule for - // popHead to never succeed, but in practice it almost - // always succeeds, so this is unlikely to flake. + // Check that at least some PopHeads succeeded. We skip this + // check in short mode because it's common enough that the + // queue will stay nearly empty all the time and a PopTail + // will happen during the window between every PushHead and + // PopHead. + if !testing.Short() && nPopHead == 0 { t.Errorf("popHead never succeeded") } } |