Locking

public protocol Locking

A type that mutually excludes execution of code such that only one unit of code is running at any given time. An implementing type may choose to have readers-writer semantics, such that many readers can read at once, or lock around all reads and writes the same way.


                    
                    
                    withReadLock(_:)

Call body with a reading lock.

If the implementing type models a readers-writer lock, this function may behave differently to withWriteLock(_:).

Declaration

Swift

func withReadLock<Return>(_ body: () throws -> Return) rethrows -> Return

Parameters


                                body

A function that reads a value while locked.

Return Value

The value returned from the given function.

withAttemptedReadLock(_:) Default implementation
Attempt to call body with a reading lock.

If the lock cannot immediately be taken, return nil instead of executing body.

See
withReadLock(_:)

Default Implementation
Declaration
Swift

func withAttemptedReadLock<Return>(_ body: () throws -> Return) rethrows -> Return?
Return Value

The value returned from the given function, or nil.


                    
                    
                    withWriteLock(_:)

Default implementation

Call body with a writing lock.

If the implementing type models a readers-writer lock, this function may behave differently to withReadLock(_:).

Default Implementation

Declaration

Swift

func withWriteLock<Return>(_ body: () throws -> Return) rethrows -> Return

Parameters


                                body

A function that writes a value while locked, then returns some value.

Return Value

The value returned from the given function.