critical-section

• Added option to use a usize sized restore state

• Clarified that acquire() must provide ordering guarantees
• Updated atomic-polyfill reference to point to portable-atomic instead
• Improved documentation for Mutex example
• Added list of some known implementations

27: Release v1.1.1 r=eldruin a=Dirbaio

Co-authored-by: Dario Nieuwenhuis dirbaio@dirbaio.net

23: Release v1.1 r=eldruin a=Dirbaio

Co-authored-by: Dario Nieuwenhuis dirbaio@dirbaio.net

21: Rename doctest from GH_6 and make it cfg(doctest) r=Dirbaio a=jannic

Co-authored-by: Jan Niehusmann jan@gondor.com

• Change name of the extern fns to avoid clash with critical-section 0.2.

Breaking changes:

• Removed all builtin impls. These are going to be provided by platform-support crates now.
• Renamed custom_impl! to set_impl!.
• RestoreState is now an opaque struct for the user, and a transparent RawRestoreState type alias for impl writers.
• RestoreState type is now configurable with Cargo features. Default is (). (previously it was fixed to u8.)
• Added own CriticalSection and Mutex types, instead of reexporting them from bare_metal.

• Implemented critical-section by forwarding to version 1.1.1

Breaking changes:

• acquire and release are only implemented if the restore-state used by version 1.1.1 is an u8 or smaller.
• No default critical-section implementation is provided.

Those breaking changes are necessary because versions <= 0.2.7 were unsound, and that was impossible to fix without a breaking change.

This version is meant to minimize that breaking change. However, all users are encouraged to upgrade to critical-section 1.1.

If you're seeing a linker error like undefined symbol: _critical_section_1_0_acquire, you're affected. To fix it:

• If your target supports std: Add the critical-section dependency to Cargo.toml enabling the std feature.

  [dependencies]
  critical-section = { version = "1.1", features = ["std"]}
  

• For single-core Cortex-M targets in privileged mode:

  [dependencies]
  cortex-m = { version = "0.7.6", features = ["critical-section-single-core"]}
  

• For single-hart RISC-V targets in privileged mode:

  [dependencies]
  riscv = { version = "0.10", features = ["critical-section-single-hart"]}
  

• For other targets: check if your HAL or architecture-support crate has a critical-section 1.0 implementation available. Otherwise, provide your own.

• Add support for AVR targets.

• Improved docs.

• Fix std implementation to allow reentrant (nested) critical sections. This would previously deadlock.

• Add support for 32bit RISC-V targets.

• Use correct #[vcfg] for wasm targets.

• Added support for wasm targets.

• Added critical section implementation for std, based on a global Mutex.

• Breaking change: use CriticalSection<'_> instead of &CriticalSection<'_>

• First release