This is a variant of DoChan that supports context propagation, such that
the context provided to the inner function will only be canceled when
there are no more waiters for a given key. This can be used to
deduplicate expensive and cancelable calls among multiple callers
safely.
Updates #11935
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ibe1fb67442a854babbc6924fd8437b02cc9e7bcf
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
