Documentation

Overview

    Package syncutil provides various synchronization utilities.

    Index

    Constants

    This section is empty.

    Variables

    This section is empty.

    Functions

    This section is empty.

    Types

    type Gate

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

      A Gate limits concurrency.

      func NewGate

      func NewGate(max int) *Gate

        NewGate returns a new gate that will only permit max operations at once.

        func (*Gate) Done

        func (g *Gate) Done()

          Done finishes an operation.

          func (*Gate) Start

          func (g *Gate) Start()

            Start starts an operation, blocking until the gate has room.

            type Group

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

              A Group is like a sync.WaitGroup and coordinates doing multiple things at once. Its zero value is ready to use.

              func (*Group) Err

              func (g *Group) Err() error

                Err waits for all previous calls to Go to complete and returns the first non-nil error, or nil.

                func (*Group) Errs

                func (g *Group) Errs() []error

                  Errs waits for all previous calls to Go to complete and returns all non-nil errors.

                  func (*Group) Go

                  func (g *Group) Go(fn func() error)

                    Go runs fn in its own goroutine, but does not wait for it to complete. Call Err or Errs to wait for all the goroutines to complete.

                    func (*Group) Wait

                    func (g *Group) Wait()

                      Wait waits for all the previous calls to Go to complete.

                      type Once

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

                        A Once will perform a successful action exactly once.

                        Unlike a sync.Once, this Once's func returns an error and is re-armed on failure.

                        func (*Once) Do

                        func (o *Once) Do(f func() error) error

                          Do calls the function f if and only if Do has not been invoked without error for this instance of Once. In other words, given

                          var once Once
                          

                          if once.Do(f) is called multiple times, only the first call will invoke f, even if f has a different value in each invocation unless f returns an error. A new instance of Once is required for each function to execute.

                          Do is intended for initialization that must be run exactly once. Since f is niladic, it may be necessary to use a function literal to capture the arguments to a function to be invoked by Do:

                          err := config.once.Do(func() error { return config.init(filename) })
                          

                          type Sem

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

                            Sem implements a semaphore that can have multiple units acquired/released at a time.

                            func NewSem

                            func NewSem(max int64) *Sem

                              NewSem creates a semaphore with max units available for acquisition.

                              func (*Sem) Acquire

                              func (s *Sem) Acquire(n int64) error

                                Acquire will deduct n units from the semaphore. If the deduction would result in the available units falling below zero, the call will block until another go routine returns units via a call to Release. If more units are requested than the semaphore is configured to hold, error will be non-nil.

                                func (*Sem) Release

                                func (s *Sem) Release(n int64)

                                  Release will return n units to the semaphore and notify any currently blocking Acquire calls.

                                  Directories

                                  Path Synopsis
                                  Package singleflight provides a duplicate function call suppression mechanism.
                                  Package singleflight provides a duplicate function call suppression mechanism.
                                  Package syncdebug contains facilities for debugging synchronization problems.
                                  Package syncdebug contains facilities for debugging synchronization problems.