lock

Documentation

Index

• type Lock
  • func NewLock(filename string) *Lock
  • func (l *Lock) ForceAcquire() bool
  • func (l *Lock) HasLocked() bool
  • func (l *Lock) LastPID() (int32, error)
  • func (l *Lock) Release()
  • func (l *Lock) SetPID(pid int)
  • func (l *Lock) TryAcquire() bool
  • func (l *Lock) Who() (string, error)
• type SetPID

Types

type Lock

type Lock struct {
	Lockfile string
	// contains filtered or unexported fields
}

Lock prevents code to run at the same time by using a lockfile

func NewLock

func NewLock(filename string) *Lock

NewLock creates a new lock

func (*Lock) ForceAcquire

func (l *Lock) ForceAcquire() bool

ForceAcquire returns true if the lock was successfully set.

If a lock file already exists, it reads the PID of the supposedly running process and check if it's still running. If there no more process with this PID, it will try to delete the lock, then recreate a new lock.

func (*Lock) HasLocked

func (l *Lock) HasLocked() bool

HasLocked check this instance (and only this one) has locked the file

func (*Lock) LastPID

func (l *Lock) LastPID() (int32, error)

LastPID returns the last PID written into the lock file.

func (*Lock) Release

func (l *Lock) Release()

Release the lockfile

func (*Lock) SetPID

func (l *Lock) SetPID(pid int)

SetPID writes down the PID in the lock file. You can run the method as many times as you want when the PID changes

func (*Lock) TryAcquire

func (l *Lock) TryAcquire() bool

TryAcquire returns true if the lock was successfully set. It returns false if a lock already exists

func (*Lock) Who

func (l *Lock) Who() (string, error)

Who owns the lock?

type SetPID

type SetPID func(pid int)

SetPID is a callback that writes the PID in the lockfile