diff --git a/src/pkg/fmt/print.go b/src/pkg/fmt/print.go index 1ea816d6d5f..2f13bcd95e9 100644 --- a/src/pkg/fmt/print.go +++ b/src/pkg/fmt/print.go @@ -124,45 +124,13 @@ type pp struct { fmt fmt } -// A cache holds a set of reusable objects. -// The slice is a stack (LIFO). -// If more are needed, the cache creates them by calling new. -type cache struct { - mu sync.Mutex - saved []interface{} - new func() interface{} +var ppFree = sync.Pool{ + New: func() interface{} { return new(pp) }, } -func (c *cache) put(x interface{}) { - c.mu.Lock() - if len(c.saved) < cap(c.saved) { - c.saved = append(c.saved, x) - } - c.mu.Unlock() -} - -func (c *cache) get() interface{} { - c.mu.Lock() - n := len(c.saved) - if n == 0 { - c.mu.Unlock() - return c.new() - } - x := c.saved[n-1] - c.saved = c.saved[0 : n-1] - c.mu.Unlock() - return x -} - -func newCache(f func() interface{}) *cache { - return &cache{saved: make([]interface{}, 0, 100), new: f} -} - -var ppFree = newCache(func() interface{} { return new(pp) }) - // newPrinter allocates a new pp struct or grab a cached one. func newPrinter() *pp { - p := ppFree.get().(*pp) + p := ppFree.Get().(*pp) p.panicking = false p.erroring = false p.fmt.init(&p.buf) @@ -178,7 +146,7 @@ func (p *pp) free() { p.buf = p.buf[:0] p.arg = nil p.value = reflect.Value{} - ppFree.put(p) + ppFree.Put(p) } func (p *pp) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent } diff --git a/src/pkg/fmt/scan.go b/src/pkg/fmt/scan.go index 5b1be5891b8..c73b8b60283 100644 --- a/src/pkg/fmt/scan.go +++ b/src/pkg/fmt/scan.go @@ -11,6 +11,7 @@ import ( "os" "reflect" "strconv" + "sync" "unicode/utf8" ) @@ -380,7 +381,9 @@ func (r *readRune) ReadRune() (rr rune, size int, err error) { return } -var ssFree = newCache(func() interface{} { return new(ss) }) +var ssFree = sync.Pool{ + New: func() interface{} { return new(ss) }, +} // newScanState allocates a new ss struct or grab a cached one. func newScanState(r io.Reader, nlIsSpace, nlIsEnd bool) (s *ss, old ssave) { @@ -395,7 +398,7 @@ func newScanState(r io.Reader, nlIsSpace, nlIsEnd bool) (s *ss, old ssave) { return } - s = ssFree.get().(*ss) + s = ssFree.Get().(*ss) if rr, ok := r.(io.RuneReader); ok { s.rr = rr } else { @@ -427,7 +430,7 @@ func (s *ss) free(old ssave) { } s.buf = s.buf[:0] s.rr = nil - ssFree.put(s) + ssFree.Put(s) } // skipSpace skips spaces and maybe newlines.