This CL adds a crate `sync` containing a type sync::Mutex which wraps
the standard library Mutex and mirrors the same methods, except that
they panic where the standard library would return a PoisonError. This
API codifies our error handling strategy around poisoned mutexes in
crosvm.
- Crosvm releases are built with panic=abort so poisoning never occurs.
A panic while a mutex is held (or ever) takes down the entire process.
Thus we would like for code not to have to consider the possibility of
poison.
- We could ask developers to always write `.lock().unwrap()` on a
standard library mutex. However, we would like to stigmatize the use
of unwrap. It is confusing to permit unwrap but only on mutex lock
results. During code review it may not always be obvious whether a
particular unwrap is unwrapping a mutex lock result or a different
error that should be handled in a more principled way.
Developers should feel free to use sync::Mutex anywhere in crosvm that
they would otherwise be using std::sync::Mutex.
TEST=boot linux
Change-Id: I9727b6f8fee439edb4a8d52cf19d59acf04d990f
Reviewed-on: https://chromium-review.googlesource.com/1359923
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Tested-by: David Tolnay <dtolnay@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Hopefully the changes are self-explanatory and uncontroversial. This
eliminates much of the noise from `cargo clippy` and, for my purposes,
gives me a reasonable way to use it as a tool when writing and reviewing
code.
Here is the Clippy invocation I was using:
cargo +nightly clippy -- -W clippy::correctness -A renamed_and_removed_lints -Aclippy::{blacklisted_name,borrowed_box,cast_lossless,cast_ptr_alignment,enum_variant_names,identity_op,if_same_then_else,mut_from_ref,needless_pass_by_value,new_without_default,new_without_default_derive,or_fun_call,ptr_arg,should_implement_trait,single_match,too_many_arguments,trivially_copy_pass_by_ref,unreadable_literal,unsafe_vector_initialization,useless_transmute}
TEST=cargo check --features wl-dmabuf,gpu,usb-emulation
TEST=boot linux
Change-Id: I55eb1b4a72beb2f762480e3333a921909314a0a2
Reviewed-on: https://chromium-review.googlesource.com/1356911
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Tested-by: David Tolnay <dtolnay@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
This wrapper will be part of usb emulation backend.
BUG=chromium:831850
TEST=local build
Change-Id: I084b15201941e4c16c4e3ff9b967e55db09db567
Reviewed-on: https://chromium-review.googlesource.com/1124870
Commit-Ready: Jingkui Wang <jkwang@google.com>
Tested-by: Jingkui Wang <jkwang@google.com>
Reviewed-by: Jingkui Wang <jkwang@google.com>
