Use fillmore-labs.com/lazydone

Signed-off-by: Oliver Eikemeier <eikemeier@fillmore-labs.com>

.codeclimate.yml

@@ -9,7 +9,6 @@ exclude_patterns:
   - "**/.*"
   - "**/*_test.go"
   - "**/*.md"
-  - "**/nocopy.go"
   - "LICENSE"
   - "go.mod"
   - "go.sum"

.github/codecov.yml

@@ -3,5 +3,3 @@ coverage:
   status:
     project: false
     patch: false
-ignore:
-  - "nocopy.go"

.golangci.yaml

@@ -19,7 +19,6 @@ linters:
     - depguard
     - exhaustruct
     - forbidigo
-    - ireturn
     - nonamedreturns
     - varnamelen
     - wrapcheck
@@ -32,3 +31,7 @@ linters-settings:
     enable-all: true
     disable:
       - require-error
+  ireturn:
+    allow:
+      - error
+      - generic

future.go

@@ -22,7 +22,7 @@ import (
 	"fmt"
 )
 
-// ErrNotReady is returned when a future is not complete.
+// ErrNotReady is returned when the future is not complete.
 var ErrNotReady = errors.New("future not ready")
 
 // Future represents a read-only view of the result of an asynchronous operation.
@@ -52,18 +52,11 @@ func (f *Future[R]) Await(ctx context.Context) (R, error) {
 
 // Try returns the cached result when ready, [ErrNotReady] otherwise.
 func (f *Future[R]) Try() (R, error) {
-	if f != nil {
-		if done := f.done.Load(); done != nil {
-			select {
-			case <-*done:
-				return f.value, f.err
-
-			default:
-			}
-		}
+	if f == nil || !f.done.Closed() {
+		return *new(R), ErrNotReady
 	}
 
-	return *new(R), ErrNotReady
+	return f.value, f.err
 }
 
 // Done returns a channel that is closed when the future is complete.
@@ -73,32 +66,17 @@ func (f *Future[_]) Done() <-chan struct{} {
 		return nil
 	}
 
-	if done := f.done.Load(); done != nil {
-		return *done
-	}
-
-	done := make(chan struct{})
-	if f.done.CompareAndSwap(nil, &done) {
-		return done
-	}
-
-	done2 := f.done.Load()
-
-	return *done2
+	return f.done.Done()
 }
 
 func (f *Future[R]) String() string {
 	if f == nil {
 		return "Future <nil>"
 	}
 
-	if done := f.done.Load(); done != nil {
-		select {
-		case <-*done:
-			return fmt.Sprintf("Future resolved: %v, %v", f.value, f.err)
-		default:
-		}
+	if !f.done.Closed() {
+		return "Future pending"
 	}
 
-	return "Future pending"
+	return fmt.Sprintf("Future resolved: %v, %v", f.value, f.err)
 }

go.mod

@@ -2,18 +2,18 @@ module fillmore-labs.com/async
 
 go 1.21
 
-toolchain go1.22.1
+toolchain go1.22.2
 
 require (
+	fillmore-labs.com/lazydone v0.0.2
 	github.com/stretchr/testify v1.9.0
 	go.uber.org/goleak v1.3.0
+	golang.org/x/sync v0.7.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/kr/pretty v0.3.1 // indirect
+	github.com/kr/text v0.2.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/sync v0.6.0
-	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,26 +1,22 @@
+fillmore-labs.com/lazydone v0.0.2 h1:y6LZlS32691K2T3mvmbYJ7qnwOTQgWG6NeG6E023EOI=
+fillmore-labs.com/lazydone v0.0.2/go.mod h1:/v+72piFl79m/Ik8noCymbQmxWD/WtJm5FCeafWdkD0=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
-github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
-github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
-github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
-golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
-golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

group/group.go

@@ -64,7 +64,7 @@ type Option interface {
 }
 
 // WithLimit is an [Option] to configure the limit of active goroutines.
-func WithLimit(limit int) Option {
+func WithLimit(limit int) Option { //nolint:ireturn
 	if limit < 1 {
 		panic("limit must be at least 1")
 	}
@@ -83,7 +83,7 @@ func (o limitOption) apply(opts *options) {
 // WithCancel is an [Option] to cancel a context on the first error.
 //
 // cancel is a function retrieved from [context.WithCancelCause].
-func WithCancel(cancel context.CancelCauseFunc) Option {
+func WithCancel(cancel context.CancelCauseFunc) Option { //nolint:ireturn
 	return cancelOption{cancel: cancel}
 }
 
@@ -135,20 +135,22 @@ func DoAsync[R any](ctx context.Context, g *Group, fn func() (R, error)) *async.
 		return p.Future()
 	}
 
-	go p.Do(func() (R, error) {
+	go func() {
 		defer g.release()
 
-		value, err := func() (value R, err error) {
-			defer g.recover(&err)
+		p.Do(func() (R, error) {
+			value, err := func() (value R, err error) {
+				defer g.recover(&err)
 
-			return fn()
-		}()
-		if err != nil {
-			g.setError(err)
-		}
+				return fn()
+			}()
+			if err != nil {
+				g.setError(err)
+			}
 
-		return value, err
-	})
+			return value, err
+		})
+	}()
 
 	return p.Future()
 }

promise.go

@@ -18,18 +18,18 @@ package async
 
 import (
 	"fmt"
-	"sync/atomic"
+
+	"fillmore-labs.com/lazydone"
 )
 
 // Promise defines the common operations for resolving a [Future] to its final value.
 //
 // An empty value is valid and must not be copied after creation. One of the resolving
 // operations may be called once from any goroutine, all subsequent calls will panic.
 type Promise[R any] struct {
-	_     noCopy
-	done  atomic.Pointer[chan struct{}] // lazy chan, signals when future has completed
-	value R                             // result value, protected by done
-	err   error                         // result error, protected by done
+	done  lazydone.Lazy // lazy chan, signals when future has completed
+	value R             // result value, protected by done
+	err   error         // result error, protected by done
 }
 
 // Future returns a [Future] for this promise.
@@ -44,7 +44,7 @@ func (p *Promise[R]) Resolve(value R) {
 	}
 
 	p.value = value
-	p.close()
+	p.done.Close()
 }
 
 // Reject breaks the promise with an error.
@@ -54,7 +54,7 @@ func (p *Promise[R]) Reject(err error) {
 	}
 
 	p.err = err
-	p.close()
+	p.done.Close()
 }
 
 // Do runs fn synchronously, fulfilling the promise once it completes.
@@ -64,27 +64,17 @@ func (p *Promise[R]) Do(fn func() (R, error)) {
 	}
 
 	p.value, p.err = fn()
-	p.close()
-}
-
-func (p *Promise[R]) close() {
-	if done := p.done.Swap(&closedChan); done != nil {
-		close(*done)
-	}
+	p.done.Close()
 }
 
 func (p *Promise[R]) String() string {
 	if p == nil {
 		return "Promise <nil>"
 	}
 
-	if done := p.done.Load(); done != nil {
-		select {
-		case <-*done:
-			return fmt.Sprintf("Promise resolved: %v, %v", p.value, p.err)
-		default:
-		}
+	if !p.done.Closed() {
+		return "Promise pending"
 	}
 
-	return "Promise pending"
+	return fmt.Sprintf("Promise resolved: %v, %v", p.value, p.err)
 }