Struct ChainLock 

pub struct ChainLock { /* private fields */ }

Exclusive advisory lock on chain.lock beside the chain in use.

Held for the kernel’s lifetime (the OS drops it on any exit, including a crash). A second kernel on the same chain is refused with the holder’s PID instead of appending to the chain concurrently.

Implementations

impl ChainLock

pub fn lock_path(checkpoint: &Path) -> PathBuf

Lock file path for a chain checkpoint (chain.json -> chain.lock).

pub fn acquire(checkpoint: &Path) -> Result<Self, String>

Take the lock for the chain at checkpoint.

Errors

The message names the holder PID and the ways out (--new-chain, kernel.chain.checkpoint_path).

pub fn try_acquire(checkpoint: &Path) -> Result<Self, ChainLockError>

acquire, telling “another kernel holds it” (a refusal no retry fixes) apart from I/O failures.

pub fn probe(checkpoint: &Path) -> Result<(), String>

Check that checkpoint’s chain is not locked, without creating or writing the lock file. Ok when no lock file exists or it is free.

pub fn path(&self) -> &Path

The lock file.

Trait Implementations

impl Debug for ChainLock

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.