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Diffstat (limited to 'vendor/golang.org/x/sync/errgroup/errgroup.go')
-rw-r--r-- | vendor/golang.org/x/sync/errgroup/errgroup.go | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/vendor/golang.org/x/sync/errgroup/errgroup.go b/vendor/golang.org/x/sync/errgroup/errgroup.go deleted file mode 100644 index 948a3ee..0000000 --- a/vendor/golang.org/x/sync/errgroup/errgroup.go +++ /dev/null @@ -1,135 +0,0 @@ -// Copyright 2016 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package errgroup provides synchronization, error propagation, and Context -// cancelation for groups of goroutines working on subtasks of a common task. -// -// [errgroup.Group] is related to [sync.WaitGroup] but adds handling of tasks -// returning errors. -package errgroup - -import ( - "context" - "fmt" - "sync" -) - -type token struct{} - -// A Group is a collection of goroutines working on subtasks that are part of -// the same overall task. -// -// A zero Group is valid, has no limit on the number of active goroutines, -// and does not cancel on error. -type Group struct { - cancel func(error) - - wg sync.WaitGroup - - sem chan token - - errOnce sync.Once - err error -} - -func (g *Group) done() { - if g.sem != nil { - <-g.sem - } - g.wg.Done() -} - -// WithContext returns a new Group and an associated Context derived from ctx. -// -// The derived Context is canceled the first time a function passed to Go -// returns a non-nil error or the first time Wait returns, whichever occurs -// first. -func WithContext(ctx context.Context) (*Group, context.Context) { - ctx, cancel := withCancelCause(ctx) - return &Group{cancel: cancel}, ctx -} - -// Wait blocks until all function calls from the Go method have returned, then -// returns the first non-nil error (if any) from them. -func (g *Group) Wait() error { - g.wg.Wait() - if g.cancel != nil { - g.cancel(g.err) - } - return g.err -} - -// Go calls the given function in a new goroutine. -// It blocks until the new goroutine can be added without the number of -// active goroutines in the group exceeding the configured limit. -// -// The first call to return a non-nil error cancels the group's context, if the -// group was created by calling WithContext. The error will be returned by Wait. -func (g *Group) Go(f func() error) { - if g.sem != nil { - g.sem <- token{} - } - - g.wg.Add(1) - go func() { - defer g.done() - - if err := f(); err != nil { - g.errOnce.Do(func() { - g.err = err - if g.cancel != nil { - g.cancel(g.err) - } - }) - } - }() -} - -// TryGo calls the given function in a new goroutine only if the number of -// active goroutines in the group is currently below the configured limit. -// -// The return value reports whether the goroutine was started. -func (g *Group) TryGo(f func() error) bool { - if g.sem != nil { - select { - case g.sem <- token{}: - // Note: this allows barging iff channels in general allow barging. - default: - return false - } - } - - g.wg.Add(1) - go func() { - defer g.done() - - if err := f(); err != nil { - g.errOnce.Do(func() { - g.err = err - if g.cancel != nil { - g.cancel(g.err) - } - }) - } - }() - return true -} - -// SetLimit limits the number of active goroutines in this group to at most n. -// A negative value indicates no limit. -// -// Any subsequent call to the Go method will block until it can add an active -// goroutine without exceeding the configured limit. -// -// The limit must not be modified while any goroutines in the group are active. -func (g *Group) SetLimit(n int) { - if n < 0 { - g.sem = nil - return - } - if len(g.sem) != 0 { - panic(fmt.Errorf("errgroup: modify limit while %v goroutines in the group are still active", len(g.sem))) - } - g.sem = make(chan token, n) -} |