Documentation
¶
Overview ¶
Package sync2 provides extra functionality along the same lines as sync.
Index ¶
Constants ¶
const ( SERVICE_STOPPED = iota SERVICE_RUNNING SERVICE_SHUTTING_DOWN )
These are the three predefined states of a service.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type AtomicDuration ¶
type AtomicDuration struct {
// contains filtered or unexported fields
}
AtomicDuration is a wrapper with a simpler interface around atomic.(Add|Store|Load|CompareAndSwap)Int64 functions.
func NewAtomicDuration ¶
func NewAtomicDuration(duration time.Duration) AtomicDuration
NewAtomicDuration initializes a new AtomicDuration with a given value.
func (*AtomicDuration) Add ¶
func (d *AtomicDuration) Add(duration time.Duration) time.Duration
Add atomically adds duration to the value.
func (*AtomicDuration) CompareAndSwap ¶
func (d *AtomicDuration) CompareAndSwap(oldval, newval time.Duration) (swapped bool)
CompareAndSwap atomatically swaps the old with the new value.
func (*AtomicDuration) Get ¶
func (d *AtomicDuration) Get() time.Duration
Get atomically returns the current value.
func (*AtomicDuration) Set ¶
func (d *AtomicDuration) Set(duration time.Duration)
Set atomically sets duration as new value.
type AtomicInt32 ¶
type AtomicInt32 struct {
// contains filtered or unexported fields
}
AtomicInt32 is a wrapper with a simpler interface around atomic.(Add|Store|Load|CompareAndSwap)Int32 functions.
func NewAtomicInt32 ¶
func NewAtomicInt32(n int32) AtomicInt32
NewAtomicInt32 initializes a new AtomicInt32 with a given value.
func (*AtomicInt32) Add ¶
func (i *AtomicInt32) Add(n int32) int32
Add atomically adds n to the value.
func (*AtomicInt32) CompareAndSwap ¶
func (i *AtomicInt32) CompareAndSwap(oldval, newval int32) (swapped bool)
CompareAndSwap atomatically swaps the old with the new value.
func (*AtomicInt32) Get ¶
func (i *AtomicInt32) Get() int32
Get atomically returns the current value.
type AtomicInt64 ¶
type AtomicInt64 struct {
// contains filtered or unexported fields
}
AtomicInt64 is a wrapper with a simpler interface around atomic.(Add|Store|Load|CompareAndSwap)Int64 functions.
func NewAtomicInt64 ¶
func NewAtomicInt64(n int64) AtomicInt64
NewAtomicInt64 initializes a new AtomicInt64 with a given value.
func (*AtomicInt64) Add ¶
func (i *AtomicInt64) Add(n int64) int64
Add atomically adds n to the value.
func (*AtomicInt64) CompareAndSwap ¶
func (i *AtomicInt64) CompareAndSwap(oldval, newval int64) (swapped bool)
CompareAndSwap atomatically swaps the old with the new value.
func (*AtomicInt64) Get ¶
func (i *AtomicInt64) Get() int64
Get atomically returns the current value.
type AtomicString ¶
type AtomicString struct {
// contains filtered or unexported fields
}
AtomicString gives you atomic-style APIs for string, but it's only a convenience wrapper that uses a mutex. So, it's not as efficient as the rest of the atomic types.
func (*AtomicString) CompareAndSwap ¶
func (s *AtomicString) CompareAndSwap(oldval, newval string) (swqpped bool)
CompareAndSwap atomatically swaps the old with the new value.
func (*AtomicString) Get ¶
func (s *AtomicString) Get() string
Get atomically returns the current value.
func (*AtomicString) Set ¶
func (s *AtomicString) Set(str string)
Set atomically sets str as new value.
type Consolidator ¶
type Consolidator struct {
// contains filtered or unexported fields
}
Consolidator consolidates duplicate queries from executing simulaneously and shares results between them.
func NewConsolidator ¶
func NewConsolidator() *Consolidator
NewConsolidator creates a new Consolidator
func (*Consolidator) Create ¶
func (co *Consolidator) Create(query string) (r *Result, created bool)
Create adds a query to currently executing queries and acquires a lock on its Result if it is not already present. If the query is a duplicate, Create returns false.
func (*Consolidator) ServeHTTP ¶
func (co *Consolidator) ServeHTTP(response http.ResponseWriter, request *http.Request)
type Result ¶
type Result struct {
Result interface{}
Err error
// contains filtered or unexported fields
}
Result is a wrapper for result of a query.
type Semaphore ¶
type Semaphore struct {
// contains filtered or unexported fields
}
Semaphore is a counting semaphore with the option to specify a timeout.
func NewSemaphore ¶
NewSemaphore creates a Semaphore. The count parameter must be a positive number. A timeout of zero means that there is no timeout.
func (*Semaphore) Release ¶
func (sem *Semaphore) Release()
Release releases the acquired semaphore. You must not release more than the number of semaphores you've acquired.
func (*Semaphore) TryAcquire ¶
TryAcquire acquires a semaphore if it's immediately available. It returns false otherwise.
type ServiceContext ¶
type ServiceContext struct {
// ShuttingDown is a channel that the service can select on to be notified
// when it should shut down. The channel is closed when the state transitions
// from SERVICE_RUNNING to SERVICE_SHUTTING_DOWN.
ShuttingDown chan struct{}
}
ServiceContext is passed into the service function to give it access to information about the running service. You can create an empty service context, in which case it will be non-cancelable.
func (*ServiceContext) IsRunning ¶
func (svc *ServiceContext) IsRunning() bool
IsRunning returns true if the ServiceContext.ShuttingDown channel has not been closed yet.
type ServiceManager ¶
type ServiceManager struct {
// contains filtered or unexported fields
}
ServiceManager manages the state of a service through its lifecycle. It's not recommended to nest service managers because they introduce race conditions in the Stop functions that can cause one service to indefinitely wait for the other. You can instead pass the top level ServiceContext around and manage shutdown using the single ServiceManager.
func (*ServiceManager) Go ¶
func (svm *ServiceManager) Go(service func(svc *ServiceContext) error) bool
Go tries to change the state from SERVICE_STOPPED to SERVICE_RUNNING.
If the current state is not SERVICE_STOPPED (already running), it returns false immediately.
On successful transition, it launches the service as a goroutine and returns true. The service function is responsible for returning on its own when requested, either by regularly checking svc.IsRunning(), or by waiting for the svc.ShuttingDown channel to be closed.
When the service func returns, the state is reverted to SERVICE_STOPPED.
func (*ServiceManager) Join ¶
func (svm *ServiceManager) Join() error
Join waits for the service to terminate and returns the value returned by the service function.
func (*ServiceManager) State ¶
func (svm *ServiceManager) State() int64
State returns the current state of the service. This should only be used to report the current state.
func (*ServiceManager) StateName ¶
func (svm *ServiceManager) StateName() string
StateName returns the name of the current state.
func (*ServiceManager) Stop ¶
func (svm *ServiceManager) Stop() bool
Stop tries to change the state from SERVICE_RUNNING to SERVICE_SHUTTING_DOWN. If the current state is not SERVICE_RUNNING, it returns false immediately. On successul transition, it waits for the service to finish, and returns true. You are allowed to Go() again after a Stop().
Source Files