diff --git a/go.mod b/go.mod index 8a09d416..9fd398c6 100644 --- a/go.mod +++ b/go.mod @@ -8,5 +8,5 @@ require ( github.com/stretchr/testify v1.8.0 github.com/teivah/onecontext v0.0.0-20200513185103-40f981bfd775 go.uber.org/goleak v1.1.12 - golang.org/x/sync v0.0.0-20210220032951-036812b2e83c + golang.org/x/sync v0.1.0 ) diff --git a/go.sum b/go.sum index 254221ee..f7b51d15 100644 --- a/go.sum +++ b/go.sum @@ -36,8 +36,9 @@ golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s= golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM= golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= -golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ= golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= +golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o= +golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= diff --git a/vendor/golang.org/x/sync/AUTHORS b/vendor/golang.org/x/sync/AUTHORS deleted file mode 100644 index 15167cd7..00000000 --- a/vendor/golang.org/x/sync/AUTHORS +++ /dev/null @@ -1,3 +0,0 @@ -# This source code refers to The Go Authors for copyright purposes. -# The master list of authors is in the main Go distribution, -# visible at http://tip.golang.org/AUTHORS. diff --git a/vendor/golang.org/x/sync/CONTRIBUTORS b/vendor/golang.org/x/sync/CONTRIBUTORS deleted file mode 100644 index 1c4577e9..00000000 --- a/vendor/golang.org/x/sync/CONTRIBUTORS +++ /dev/null @@ -1,3 +0,0 @@ -# This source code was written by the Go contributors. -# The master list of contributors is in the main Go distribution, -# visible at http://tip.golang.org/CONTRIBUTORS. diff --git a/vendor/golang.org/x/sync/errgroup/errgroup.go b/vendor/golang.org/x/sync/errgroup/errgroup.go index 9857fe53..cbee7a4e 100644 --- a/vendor/golang.org/x/sync/errgroup/errgroup.go +++ b/vendor/golang.org/x/sync/errgroup/errgroup.go @@ -8,22 +8,35 @@ 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 and does not cancel on error. +// 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() 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 @@ -45,14 +58,48 @@ func (g *Group) Wait() error { } // 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; its error will be -// returned by Wait. +// 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() + } + }) + } + }() +} + +// 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.wg.Done() + defer g.done() if err := f(); err != nil { g.errOnce.Do(func() { @@ -63,4 +110,23 @@ func (g *Group) Go(f func() error) { }) } }() + 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) } diff --git a/vendor/modules.txt b/vendor/modules.txt index c65cc3f8..14f41ba2 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -21,7 +21,7 @@ github.com/teivah/onecontext # go.uber.org/goleak v1.1.12 go.uber.org/goleak go.uber.org/goleak/internal/stack -# golang.org/x/sync v0.0.0-20210220032951-036812b2e83c +# golang.org/x/sync v0.1.0 golang.org/x/sync/errgroup # gopkg.in/yaml.v3 v3.0.1 gopkg.in/yaml.v3