# Read/Write Locks

The :std/misc/rwlock include an implementation of read/write locks.

The implementation queues additional readers when there are writers waiting, so that no new readers will acquire the lock until all writers are done. This ensures that writers cannot be starved, which is a very important property for read/write locks.

(import :std/misc/rwlock)

# make-rwlock

(make-rwlock [name 'rwlock]) -> rwlock

Creates a (named) read-write lock.

# rwlock?

(rwlock? obj) -> bool

Type predicate for rwlocks.

# rwlock-read-lock!

(rwlock-read-lock! rwlock)

Acquires a read lock on rwlock; multiple readers can acquire the read lock simultaneously.

# rwlock-read-unlock!

(rwlock-read-unlock! rwlock)

Releases a read lock on rwlock.

# rwlock-write-lock!

(rwlock-write-lock! rwlock)

Acquires an exclusive write lock on rwlock.

# rwlock-write-unlock!

(rwlock-write-unlock! rwlock)

Release an exclusive write lock on rwlock.

# with-read-lock

(with-read-lock rwlock proc)

Evaluates proc while holding a read lock on rwlock and returns the result.

# with-write-lock

(with-write-lock rwlock proc)

Evaluates proc while holding a write lock on rwlock and returns the result.