tari_utilities/

locks.rs

// Copyright 2019, The Tari Project
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//! Macros for RwLock.

/// Recovers a poisoned lock by returning the value before the lock was poisoned
#[macro_export]
macro_rules! recover_lock {
    ($e:expr) => {
        match $e {
            Ok(lock) => lock,
            Err(poisoned) => {
                log::warn!(target: "tari_util", "Lock has been POISONED and will be silently recovered");
                poisoned.into_inner()
            },
        }
    };
}

/// This macro returns a Mutex or RwLock guard without returning a `PoisonError`.
/// If the lock is poisoned (i.e. a panic before a MutexGuard / RwLockGuard is dropped), the last value before the panic
/// occurred is used. The semantics of this macro are similar to a database transaction rollback on failure.
#[macro_export]
macro_rules! acquire_lock {
    ($e:expr, $m:ident) => {
        $crate::recover_lock!($e.$m())
    };
    ($e:expr) => {
        $crate::acquire_lock!($e, lock)
    };
}

/// Acquire a write lock on a RwLock, silently recovering the lock if it is poisoned
#[macro_export]
macro_rules! acquire_write_lock {
    ($e:expr) => {
        $crate::acquire_lock!($e, write)
    };
}

/// Acquire a read lock on a RwLock, silently recovering the lock if it is poisoned
#[macro_export]
macro_rules! acquire_read_lock {
    ($e:expr) => {
        $crate::acquire_lock!($e, read)
    };
}