From 8d2b4cb6cc3100f337e08cc7342f42823fa1dc9a Mon Sep 17 00:00:00 2001 From: Dan Scales Date: Mon, 10 May 2021 16:23:35 -0700 Subject: [PATCH] [dev.typeparams] cmd/compile: fixing import of comm clauses/closures in generic functions Improvements: - Fix export/import of the default case of a select statement (was not dealing with nil Comm case) - Set properly the name of closure functions in imported generic functions Added new test exporting/importing a reasonably large channel package, chansimp.go. Change-Id: If2ee12bd749e5df415f48ec4b629a2fa68a79dcb Reviewed-on: https://go-review.googlesource.com/c/go/+/321734 Run-TryBot: Dan Scales TryBot-Result: Go Bot Reviewed-by: Keith Randall Trust: Dan Scales --- src/cmd/compile/internal/typecheck/iexport.go | 7 +- src/cmd/compile/internal/typecheck/iimport.go | 14 +- test/typeparam/chansimp.dir/a.go | 232 ++++++++++++++++++ test/typeparam/chansimp.dir/main.go | 189 ++++++++++++++ test/typeparam/chansimp.go | 7 + 5 files changed, 447 insertions(+), 2 deletions(-) create mode 100644 test/typeparam/chansimp.dir/a.go create mode 100644 test/typeparam/chansimp.dir/main.go create mode 100644 test/typeparam/chansimp.go diff --git a/src/cmd/compile/internal/typecheck/iexport.go b/src/cmd/compile/internal/typecheck/iexport.go index 802a8c3839..d956ada3c5 100644 --- a/src/cmd/compile/internal/typecheck/iexport.go +++ b/src/cmd/compile/internal/typecheck/iexport.go @@ -1523,7 +1523,12 @@ func (w *exportWriter) commList(cases []*ir.CommClause) { w.uint64(uint64(len(cases))) for _, cas := range cases { w.pos(cas.Pos()) - w.node(cas.Comm) + defaultCase := cas.Comm == nil + w.bool(defaultCase) + if !defaultCase { + // Only call w.node for non-default cause (cas.Comm is non-nil) + w.node(cas.Comm) + } w.stmtList(cas.Body) } } diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go index 39b5ab09da..966e865630 100644 --- a/src/cmd/compile/internal/typecheck/iimport.go +++ b/src/cmd/compile/internal/typecheck/iimport.go @@ -1121,7 +1121,13 @@ func (r *importReader) caseList(switchExpr ir.Node) []*ir.CaseClause { func (r *importReader) commList() []*ir.CommClause { cases := make([]*ir.CommClause, r.uint64()) for i := range cases { - cases[i] = ir.NewCommStmt(r.pos(), r.node(), r.stmtList()) + pos := r.pos() + defaultCase := r.bool() + var comm ir.Node + if !defaultCase { + comm = r.node() + } + cases[i] = ir.NewCommStmt(pos, comm, r.stmtList()) } return cases } @@ -1257,6 +1263,12 @@ func (r *importReader) node() ir.Node { if go117ExportTypes { clo.SetType(typ) } + if r.curfn.Type().HasTParam() { + // Generic functions aren't inlined, so give the closure a + // function name now, which is then available for use + // (after appending the type args) for each stenciling. + fn.Nname.SetSym(ClosureName(r.curfn)) + } return clo diff --git a/test/typeparam/chansimp.dir/a.go b/test/typeparam/chansimp.dir/a.go new file mode 100644 index 0000000000..a3f73b2199 --- /dev/null +++ b/test/typeparam/chansimp.dir/a.go @@ -0,0 +1,232 @@ +// Copyright 2021 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 a + +import ( + "context" + "runtime" +) + +// Equal reports whether two slices are equal: the same length and all +// elements equal. All floating point NaNs are considered equal. +func SliceEqual[Elem comparable](s1, s2 []Elem) bool { + if len(s1) != len(s2) { + return false + } + for i, v1 := range s1 { + v2 := s2[i] + if v1 != v2 { + isNaN := func(f Elem) bool { return f != f } + if !isNaN(v1) || !isNaN(v2) { + return false + } + } + } + return true +} + +// ReadAll reads from c until the channel is closed or the context is +// canceled, returning all the values read. +func ReadAll[Elem any](ctx context.Context, c <-chan Elem) []Elem { + var r []Elem + for { + select { + case <-ctx.Done(): + return r + case v, ok := <-c: + if !ok { + return r + } + r = append(r, v) + } + } +} + +// Merge merges two channels into a single channel. +// This will leave a goroutine running until either both channels are closed +// or the context is canceled, at which point the returned channel is closed. +func Merge[Elem any](ctx context.Context, c1, c2 <-chan Elem) <-chan Elem { + r := make(chan Elem) + go func(ctx context.Context, c1, c2 <-chan Elem, r chan<- Elem) { + defer close(r) + for c1 != nil || c2 != nil { + select { + case <-ctx.Done(): + return + case v1, ok := <-c1: + if ok { + r <- v1 + } else { + c1 = nil + } + case v2, ok := <-c2: + if ok { + r <- v2 + } else { + c2 = nil + } + } + } + }(ctx, c1, c2, r) + return r +} + +// Filter calls f on each value read from c. If f returns true the value +// is sent on the returned channel. This will leave a goroutine running +// until c is closed or the context is canceled, at which point the +// returned channel is closed. +func Filter[Elem any](ctx context.Context, c <-chan Elem, f func(Elem) bool) <-chan Elem { + r := make(chan Elem) + go func(ctx context.Context, c <-chan Elem, f func(Elem) bool, r chan<- Elem) { + defer close(r) + for { + select { + case <-ctx.Done(): + return + case v, ok := <-c: + if !ok { + return + } + if f(v) { + r <- v + } + } + } + }(ctx, c, f, r) + return r +} + +// Sink returns a channel that discards all values sent to it. +// This will leave a goroutine running until the context is canceled +// or the returned channel is closed. +func Sink[Elem any](ctx context.Context) chan<- Elem { + r := make(chan Elem) + go func(ctx context.Context, r <-chan Elem) { + for { + select { + case <-ctx.Done(): + return + case _, ok := <-r: + if !ok { + return + } + } + } + }(ctx, r) + return r +} + +// An Exclusive is a value that may only be used by a single goroutine +// at a time. This is implemented using channels rather than a mutex. +type Exclusive[Val any] struct { + c chan Val +} + +// MakeExclusive makes an initialized exclusive value. +func MakeExclusive[Val any](initial Val) *Exclusive[Val] { + r := &Exclusive[Val]{ + c: make(chan Val, 1), + } + r.c <- initial + return r +} + +// Acquire acquires the exclusive value for private use. +// It must be released using the Release method. +func (e *Exclusive[Val]) Acquire() Val { + return <-e.c +} + +// TryAcquire attempts to acquire the value. The ok result reports whether +// the value was acquired. If the value is acquired, it must be released +// using the Release method. +func (e *Exclusive[Val]) TryAcquire() (v Val, ok bool) { + select { + case r := <-e.c: + return r, true + default: + return v, false + } +} + +// Release updates and releases the value. +// This method panics if the value has not been acquired. +func (e *Exclusive[Val]) Release(v Val) { + select { + case e.c <- v: + default: + panic("Exclusive Release without Acquire") + } +} + +// Ranger returns a Sender and a Receiver. The Receiver provides a +// Next method to retrieve values. The Sender provides a Send method +// to send values and a Close method to stop sending values. The Next +// method indicates when the Sender has been closed, and the Send +// method indicates when the Receiver has been freed. +// +// This is a convenient way to exit a goroutine sending values when +// the receiver stops reading them. +func Ranger[Elem any]() (*Sender[Elem], *Receiver[Elem]) { + c := make(chan Elem) + d := make(chan struct{}) + s := &Sender[Elem]{ + values: c, + done: d, + } + r := &Receiver[Elem] { + values: c, + done: d, + } + runtime.SetFinalizer(r, (*Receiver[Elem]).finalize) + return s, r +} + +// A Sender is used to send values to a Receiver. +type Sender[Elem any] struct { + values chan<- Elem + done <-chan struct{} +} + +// Send sends a value to the receiver. It reports whether the value was sent. +// The value will not be sent if the context is closed or the receiver +// is freed. +func (s *Sender[Elem]) Send(ctx context.Context, v Elem) bool { + select { + case <-ctx.Done(): + return false + case s.values <- v: + return true + case <-s.done: + return false + } +} + +// Close tells the receiver that no more values will arrive. +// After Close is called, the Sender may no longer be used. +func (s *Sender[Elem]) Close() { + close(s.values) +} + +// A Receiver receives values from a Sender. +type Receiver[Elem any] struct { + values <-chan Elem + done chan<- struct{} +} + +// Next returns the next value from the channel. The bool result indicates +// whether the value is valid. +func (r *Receiver[Elem]) Next(ctx context.Context) (v Elem, ok bool) { + select { + case <-ctx.Done(): + case v, ok = <-r.values: + } + return v, ok +} + +// finalize is a finalizer for the receiver. +func (r *Receiver[Elem]) finalize() { + close(r.done) +} diff --git a/test/typeparam/chansimp.dir/main.go b/test/typeparam/chansimp.dir/main.go new file mode 100644 index 0000000000..ca27167598 --- /dev/null +++ b/test/typeparam/chansimp.dir/main.go @@ -0,0 +1,189 @@ +// Copyright 2021 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 main + +import ( + "a" + "context" + "fmt" + "runtime" + "sort" + "sync" + "time" +) + +func TestReadAll() { + c := make(chan int) + go func() { + c <- 4 + c <- 2 + c <- 5 + close(c) + }() + got := a.ReadAll(context.Background(), c) + want := []int{4, 2, 5} + if !a.SliceEqual(got, want) { + panic(fmt.Sprintf("ReadAll returned %v, want %v", got, want)) + } +} + +func TestMerge() { + c1 := make(chan int) + c2 := make(chan int) + go func() { + c1 <- 1 + c1 <- 3 + c1 <- 5 + close(c1) + }() + go func() { + c2 <- 2 + c2 <- 4 + c2 <- 6 + close(c2) + }() + ctx := context.Background() + got := a.ReadAll(ctx, a.Merge(ctx, c1, c2)) + sort.Ints(got) + want := []int{1, 2, 3, 4, 5, 6} + if !a.SliceEqual(got, want) { + panic(fmt.Sprintf("Merge returned %v, want %v", got, want)) + } +} + +func TestFilter() { + c := make(chan int) + go func() { + c <- 1 + c <- 2 + c <- 3 + close(c) + }() + even := func(i int) bool { return i%2 == 0 } + ctx := context.Background() + got := a.ReadAll(ctx, a.Filter(ctx, c, even)) + want := []int{2} + if !a.SliceEqual(got, want) { + panic(fmt.Sprintf("Filter returned %v, want %v", got, want)) + } +} + +func TestSink() { + c := a.Sink[int](context.Background()) + after := time.NewTimer(time.Minute) + defer after.Stop() + send := func(v int) { + select { + case c <- v: + case <-after.C: + panic("timed out sending to Sink") + } + } + send(1) + send(2) + send(3) + close(c) +} + +func TestExclusive() { + val := 0 + ex := a.MakeExclusive(&val) + + var wg sync.WaitGroup + f := func() { + defer wg.Done() + for i := 0; i < 10; i++ { + p := ex.Acquire() + (*p)++ + ex.Release(p) + } + } + + wg.Add(2) + go f() + go f() + + wg.Wait() + if val != 20 { + panic(fmt.Sprintf("after Acquire/Release loop got %d, want 20", val)) + } +} + +func TestExclusiveTry() { + s := "" + ex := a.MakeExclusive(&s) + p, ok := ex.TryAcquire() + if !ok { + panic("TryAcquire failed") + } + *p = "a" + + var wg sync.WaitGroup + wg.Add(1) + go func() { + defer wg.Done() + _, ok := ex.TryAcquire() + if ok { + panic(fmt.Sprintf("TryAcquire succeeded unexpectedly")) + } + }() + wg.Wait() + + ex.Release(p) + + p, ok = ex.TryAcquire() + if !ok { + panic(fmt.Sprintf("TryAcquire failed")) + } +} + +func TestRanger() { + s, r := a.Ranger[int]() + + ctx := context.Background() + go func() { + // Receive one value then exit. + v, ok := r.Next(ctx) + if !ok { + panic(fmt.Sprintf("did not receive any values")) + } else if v != 1 { + panic(fmt.Sprintf("received %d, want 1", v)) + } + }() + + c1 := make(chan bool) + c2 := make(chan bool) + go func() { + defer close(c2) + if !s.Send(ctx, 1) { + panic(fmt.Sprintf("Send failed unexpectedly")) + } + close(c1) + if s.Send(ctx, 2) { + panic(fmt.Sprintf("Send succeeded unexpectedly")) + } + }() + + <-c1 + + // Force a garbage collection to try to get the finalizers to run. + runtime.GC() + + select { + case <-c2: + case <-time.After(time.Minute): + panic("Ranger Send should have failed, but timed out") + } +} + +func main() { + TestReadAll() + TestMerge() + TestFilter() + TestSink() + TestExclusive() + TestExclusiveTry() + TestRanger() +} diff --git a/test/typeparam/chansimp.go b/test/typeparam/chansimp.go new file mode 100644 index 0000000000..76930e5e4f --- /dev/null +++ b/test/typeparam/chansimp.go @@ -0,0 +1,7 @@ +// rundir -G=3 + +// Copyright 2021 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 ignored