lock

Documentation

Index

• type Map
  • func (m *Map[K, V]) Delete(key K)
  • func (m *Map[K, V]) Load(key K) (value V, ok bool)
  • func (m *Map[K, V]) LoadAndDelete(key K) (value V, loaded bool)
  • func (m *Map[K, V]) LoadOrStore(key K, value V) (actual V, loaded bool)
  • func (m *Map[K, V]) Range(f func(key K, value V) bool)
  • func (m *Map[K, V]) Store(key K, value V)
  • func (m *Map[K, V]) Swap(key K, value V) (previous V, loaded bool)
• type MapCmpValues
  • func (m *MapCmpValues[K, V]) CompareAndDelete(key K, old V) (deleted bool)
  • func (m *MapCmpValues[K, V]) CompareAndSwap(key K, old, new V) bool
• type Mutex
  • func (i *Mutex) UnlockIgnoreTime()
• type MutexDebug
• type RWMutex
  • func (i *RWMutex) UnlockIgnoreTime()
• type RWMutexDebug
• type SemaphoredMutex
  • func NewSemaphoredMutex() SemaphoredMutex
  • func (i *SemaphoredMutex) Lock()
  • func (i *SemaphoredMutex) RLock()
  • func (i *SemaphoredMutex) RUnlock()
  • func (i *SemaphoredMutex) Unlock()
  • func (i *SemaphoredMutex) UnlockToRLock()
• type SortableMutex
  • func NewSortableMutex() SortableMutex
• type SortableMutexes
  • func (s SortableMutexes) Len() int
  • func (s SortableMutexes) Less(i int, j int) bool
  • func (s SortableMutexes) Lock()
  • func (s SortableMutexes) Swap(i int, j int)
  • func (s SortableMutexes) Unlock()
• type StoppableWaitGroup
  • func NewStoppableWaitGroup() *StoppableWaitGroup
  • func (l *StoppableWaitGroup) Add()
  • func (l *StoppableWaitGroup) Done()
  • func (l *StoppableWaitGroup) Stop()
  • func (l *StoppableWaitGroup) Wait()
  • func (l *StoppableWaitGroup) WaitChannel() <-chan struct{}

Types

type Map

type Map[K comparable, V any] sync.Map

Map is a thin generic wrapper around sync.Map. The sync.Map description from the standard library follows (and is also propagated to the corresponding methods) for users' convenience:

Map is like a Go map[interface{}]interface{} but is safe for concurrent use by multiple goroutines without additional locking or coordination. Loads, stores, and deletes run in amortized constant time.

The Map type is specialized. Most code should use a plain Go map instead, with separate locking or coordination, for better type safety and to make it easier to maintain other invariants along with the map content.

The Map type is optimized for two common use cases: (1) when the entry for a given key is only ever written once but read many times, as in caches that only grow, or (2) when multiple goroutines read, write, and overwrite entries for disjoint sets of keys. In these two cases, use of a Map may significantly reduce lock contention compared to a Go map paired with a separate Mutex or RWMutex.

The zero Map is empty and ready for use. A Map must not be copied after first use.

func (*Map[K, V]) Delete

func (m *Map[K, V]) Delete(key K)

Delete deletes the value for a key.

func (*Map[K, V]) Load

func (m *Map[K, V]) Load(key K) (value V, ok bool)

Load returns the value stored in the map for a key, or the zero value if no value is present. The ok result indicates whether value was found in the map.

func (*Map[K, V]) LoadAndDelete

func (m *Map[K, V]) LoadAndDelete(key K) (value V, loaded bool)

LoadAndDelete deletes the value for a key, returning the previous value if any (zero value otherwise). The loaded result reports whether the key was present.

func (*Map[K, V]) LoadOrStore

func (m *Map[K, V]) LoadOrStore(key K, value V) (actual V, loaded bool)

LoadOrStore returns the existing value for the key if present. Otherwise, it stores and returns the given value. The loaded result is true if the value was loaded, false if stored.

func (*Map[K, V]) Range

func (m *Map[K, V]) Range(f func(key K, value V) bool)

Range calls f sequentially for each key and value present in the map. If f returns false, range stops the iteration.

Range does not necessarily correspond to any consistent snapshot of the Map's contents: no key will be visited more than once, but if the value for any key is stored or deleted concurrently (including by f), Range may reflect any mapping for that key from any point during the Range call. Range does not block other methods on the receiver; even f itself may call any method on m.

Range may be O(N) with the number of elements in the map even if f returns false after a constant number of calls.

func (*Map[K, V]) Store

func (m *Map[K, V]) Store(key K, value V)

Store sets the value for a key.

func (*Map[K, V]) Swap

func (m *Map[K, V]) Swap(key K, value V) (previous V, loaded bool)

Swap swaps the value for a key and returns the previous value if any (zero value otherwise). The loaded result reports whether the key was present.

type MapCmpValues

type MapCmpValues[K, V comparable] Map[K, V]

MapCmpValues is an extension of Map, which additionally wraps the two extra methods requiring values to be also of comparable type.

func (*MapCmpValues[K, V]) CompareAndDelete

func (m *MapCmpValues[K, V]) CompareAndDelete(key K, old V) (deleted bool)

CompareAndDelete deletes the entry for key if its value is equal to old. If there is no current value for key in the map, CompareAndDelete returns false (even if the old value is the nil interface value).

func (*MapCmpValues[K, V]) CompareAndSwap

func (m *MapCmpValues[K, V]) CompareAndSwap(key K, old, new V) bool

CompareAndSwap swaps the old and new values for key if the value stored in the map is equal to old.

type Mutex

type Mutex struct {
	// contains filtered or unexported fields
}

Mutex is equivalent to sync.Mutex but applies deadlock detection if the built tag "lockdebug" is set

func (*Mutex) UnlockIgnoreTime

func (i *Mutex) UnlockIgnoreTime()

type MutexDebug

type MutexDebug struct {
	deadlock.Mutex
}

MutexDebug is a MutexDebug with deadlock detection regardless of use of the build tag

type RWMutex

type RWMutex struct {
	// contains filtered or unexported fields
}

RWMutex is equivalent to sync.RWMutex but applies deadlock detection if the built tag "lockdebug" is set

func (*RWMutex) UnlockIgnoreTime

func (i *RWMutex) UnlockIgnoreTime()

type RWMutexDebug

type RWMutexDebug struct {
	deadlock.RWMutex
}

RWMutexDebug is a RWMutexDebug with deadlock detection regardless of use of the build tag

type SemaphoredMutex

type SemaphoredMutex struct {
	// contains filtered or unexported fields
}

SemaphoredMutex is a semaphored mutex that provides a RWLocker interface.

func NewSemaphoredMutex

func NewSemaphoredMutex() SemaphoredMutex

NewSemaphoredMutex returns a new SemaphoredMutex.

func (*SemaphoredMutex) Lock

func (i *SemaphoredMutex) Lock()

func (*SemaphoredMutex) RLock

func (i *SemaphoredMutex) RLock()

func (*SemaphoredMutex) RUnlock

func (i *SemaphoredMutex) RUnlock()

func (*SemaphoredMutex) Unlock

func (i *SemaphoredMutex) Unlock()

func (*SemaphoredMutex) UnlockToRLock

func (i *SemaphoredMutex) UnlockToRLock()

UnlockToRLock releases the current lock for writing but it still keeps it for reading purposes.

type SortableMutex

type SortableMutex interface {
	sync.Locker
	Seq() uint64
	AcquireDuration() time.Duration // The amount of time it took to acquire the lock
}

SortableMutex provides a Mutex that can be globally sorted with other sortable mutexes. This allows deadlock-safe locking of a set of mutexes as it guarantees consistent lock ordering.

func NewSortableMutex

func NewSortableMutex() SortableMutex

type SortableMutexes

type SortableMutexes []SortableMutex

SortableMutexes is a set of mutexes that can be locked in a safe order. Once Lock() is called it must not be mutated!

func (SortableMutexes) Len

func (s SortableMutexes) Len() int

Len implements sort.Interface.

func (SortableMutexes) Less

func (s SortableMutexes) Less(i int, j int) bool

Less implements sort.Interface.

func (SortableMutexes) Lock

func (s SortableMutexes) Lock()

Lock sorts the mutexes, and then locks them in order. If any lock cannot be acquired, this will block while holding the locks with a lower sequence number.

func (SortableMutexes) Swap

func (s SortableMutexes) Swap(i int, j int)

Swap implements sort.Interface.

func (SortableMutexes) Unlock

func (s SortableMutexes) Unlock()

Unlock locks the sorted set of mutexes locked by prior call to Lock().

type StoppableWaitGroup

type StoppableWaitGroup struct {
	// contains filtered or unexported fields
}

A StoppableWaitGroup waits for a collection of goroutines to finish.

func NewStoppableWaitGroup

func NewStoppableWaitGroup() *StoppableWaitGroup

NewStoppableWaitGroup returns a new StoppableWaitGroup. When the 'Stop' is executed, following 'Add()' calls won't have any effect.

func (*StoppableWaitGroup) Add

func (l *StoppableWaitGroup) Add()

Add adds the goroutine to the list of routines to that Wait() will have to wait before it returns. If the StoppableWaitGroup was stopped this will be a no-op.

func (*StoppableWaitGroup) Done

func (l *StoppableWaitGroup) Done()

Done will decrement the number of goroutines the Wait() will have to wait before it returns. This function is a no-op once all goroutines that have called 'Add()' have also called 'Done()' and the StoppableWaitGroup was stopped.

func (*StoppableWaitGroup) Stop

func (l *StoppableWaitGroup) Stop()

Stop makes following 'Add()' to be considered a no-op. If all goroutines that have called Add also called Done, 'Wait()' will be immediately unblocked.

func (*StoppableWaitGroup) Wait

func (l *StoppableWaitGroup) Wait()

Wait will return once all goroutines that have called Add also called Done and StoppableWaitGroup was stopped. Internally, Wait() returns once the internal counter becomes negative.

func (*StoppableWaitGroup) WaitChannel

func (l *StoppableWaitGroup) WaitChannel() <-chan struct{}

WaitChannel will return a channel that will be closed once all goroutines that have called Add also called Done and StoppableWaitGroup was stopped.