When backporting patches to LTS branches, we often run into CI failures due to
changes in rust. Newer rust versions add more lints, which break CI. We really
don't want to also have to backport patches that fix CI, so instead, LTS branches
should pin the stable rust version in CI (e.g. #4434).
This PR restructures the CI config files to make it a bit easier to set a specific rust
version in CI.
A first pass at updating Tokio to use `std::future`.
Implementations of `Future` from the futures crate are updated to implement
`Future` from std. Implementations of `Stream` are moved to a feature flag.
This commits disables a number of crates that have not yet been updated.
## Motivation
`tokio-trace` currently offers a strategy for compatibility with the
`log` crate: its macros can be dropped in as a replacement for `log`'s
macros, and a subscriber can be used that translates trace events to log
records. However, this requires the application to be aware of
`tokio-trace` and manually set up this subscriber.
Many libraries currently emit `log` records, and would like to be able
to emit `tokio-trace` instrumentation instead. The `tokio` runtimes are
one such example. However, with the current log compatibility strategy,
replacing existing logging with trace instrumentation would break
`tokio`'s logs for any downstream user which is using only `log` and not
`tokio-trace`. It is desirable for libraries to have the option to emit
both `log` _and_ `tokio-trace` diagnostics from the same instrumentation
points.
## Solution
This branch adds a `log` feature flag to the `tokio-trace` crate, which
when set, causes `tokio-trace` instrumentation to emit log records as well
as `tokio-trace` instrumentation.
## Notes
In order to allow spans to log their names when they are entered and
exited even when the span is disabled, this branch adds an
`&'static Metadata` to the `Span` type. This was previously stored in
the `Inner` type and was thus only present when the span was enabled.
This makes disabled spans one word longer, but enabled spans remain
the same size.
Fixes: #949
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
## Motivation
`tokio-trace` should have static verbosity level filtering, like the
`log` crate. The static max verbosity level should be controlled at
compile time with a set of features. It should be possible to set a
separate max level for release and debug mode builds.
## Solution
We can do this fairly similarly to how the `log` crate does it:
`tokio-trace` should export a constant whose value is set based on the
static max level feature flags. Then, we add an if statement to the
`span!` and `event!` macros which tests if that event or span's level
is enabled.
Closes#959
#993 introduces changes in a sub crate that other Tokio crates depend
on. To make CI pass, a `[patch]` statement and `path` dependencies are
used.
When releasing, these must be removed. However, the commit that
removes them and prepares the crates for release will not be able to
pass CI.
This commit adds a conditional on a special `[ci-release]` snippet in
the commit message. If this exists, CI is only run with the full "patched"
dependencies.
