rundown_protection

README

Rundown-Protection

Golang implementation of a rundown protection for accessing a shared object.

Some times we need to access a shared resource than can be created and deleted by a routine we don't control. Or the opposite, we know when we create and delete the resource but we don't control when it is accessed.

Unlike sync.WaitGroup, this library does not panic if you try to access an unavailable resource. Just check the return Acquire method to ensure if you can safely use the resource.

Usage

import rp "github.com/randlabs/rundown-protection"

//create a new rundown protection object.
r := rp.Create()

if r.Acquire() {
    //access granted
    go func() {
        //use the shared resource
        r.Release()
    }()
}

//wait until all references to the shared resource are released
r.Wait()

//trying to acquire the shared resource will fail
if r.Acquire() {
    //this code is never executed
}

Run demo: go run ./_examples/demo.go

License

See LICENSE file for details.

Documentation

Index

• type RundownProtection
  • func Create() *RundownProtection
  • func (r *RundownProtection) Acquire() bool
  • func (_ *RundownProtection) Deadline() (deadline time.Time, ok bool)
  • func (r *RundownProtection) Done() <-chan struct{}
  • func (r *RundownProtection) Err() error
  • func (r *RundownProtection) Initialize()
  • func (r *RundownProtection) Release()
  • func (_ *RundownProtection) Value(_ any) any
  • func (r *RundownProtection) Wait()

Types

type RundownProtection

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

func Create

func Create() *RundownProtection

Create creates a new rundown protection object.

func (*RundownProtection) Acquire

func (r *RundownProtection) Acquire() bool

Acquire increments the usage counter unless a rundown is in progress.

func (*RundownProtection) Deadline

func (_ *RundownProtection) Deadline() (deadline time.Time, ok bool)

Deadline returns the time when work done on behalf of this context should be canceled.

func (*RundownProtection) Done

func (r *RundownProtection) Done() <-chan struct{}

Done returns a channel that's closed when work done on behalf of this context should be canceled.

func (*RundownProtection) Err

func (r *RundownProtection) Err() error

Err returns a non-nil error explaining why the channel was closed or nil if still open.

func (*RundownProtection) Initialize

func (r *RundownProtection) Initialize()

Initialize initializes a rundown protection object.

func (*RundownProtection) Release

func (r *RundownProtection) Release()

Release decrements the usage counter.

func (*RundownProtection) Value

func (_ *RundownProtection) Value(_ any) any

Value returns the value associated with this context for key, if any exists, or nil.

func (*RundownProtection) Wait

func (r *RundownProtection) Wait()

Wait initiates the shutdown process and waits until all acquisitions are released.