testserver: concurrent downloads about cockroach-go HOT 2 CLOSED

@georgysavva Thanks for the question. I believe the concurrency issue you describe does not affect the testserver.

As you say, if both processes see that the file does not exist, they will both call the downloadFile function to create the file and download into it. The first thing this function does is create the file with os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0200). This call will return an error if the file already exists. So one process will successfully create the file, and the other will fail. On most filesystems, this file creation is atomic. For more details, read about the O_EXCL flag here: https://linux.die.net/man/2/open.

If you're still affected by the issue, could you please re-open this, and provide a way to reproduce it?

from cockroach-go.

Thanks for the answer. Everything is clear.

from cockroach-go.