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https://github.com/golang/go
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67f8a81316
Call frame allocations can account for significant portion of all allocations in a program, if call is executed in an inner loop (e.g. to process every line in a log). On the other hand, the allocation is easy to remove using sync.Pool since the allocation is strictly scoped. benchmark old ns/op new ns/op delta BenchmarkCall 634 338 -46.69% BenchmarkCall-4 496 167 -66.33% benchmark old allocs new allocs delta BenchmarkCall 1 0 -100.00% BenchmarkCall-4 1 0 -100.00% Update #7818 Change-Id: Icf60cce0a9be82e6171f0c0bd80dee2393db54a7 Reviewed-on: https://go-review.googlesource.com/1954 Reviewed-by: Keith Randall <khr@golang.org>
47 lines
1.2 KiB
Go
47 lines
1.2 KiB
Go
// Copyright 2012 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package reflect
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// MakeRO returns a copy of v with the read-only flag set.
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func MakeRO(v Value) Value {
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v.flag |= flagRO
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return v
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}
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// IsRO reports whether v's read-only flag is set.
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func IsRO(v Value) bool {
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return v.flag&flagRO != 0
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}
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var ArrayOf = arrayOf
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var CallGC = &callGC
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const PtrSize = ptrSize
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const BitsPointer = bitsPointer
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const BitsScalar = bitsScalar
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func FuncLayout(t Type, rcvr Type) (frametype Type, argSize, retOffset uintptr, stack []byte, gc []byte, ptrs bool) {
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var ft *rtype
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var s *bitVector
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if rcvr != nil {
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ft, argSize, retOffset, s, _ = funcLayout(t.(*rtype), rcvr.(*rtype))
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} else {
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ft, argSize, retOffset, s, _ = funcLayout(t.(*rtype), nil)
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}
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frametype = ft
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for i := uint32(0); i < s.n; i += 2 {
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stack = append(stack, s.data[i/8]>>(i%8)&3)
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}
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if ft.kind&kindGCProg != 0 {
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panic("can't handle gc programs")
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}
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gcdata := (*[1000]byte)(ft.gc[0])
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for i := uintptr(0); i < ft.size/ptrSize; i++ {
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gc = append(gc, gcdata[i/2]>>(i%2*4+2)&3)
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}
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ptrs = ft.kind&kindNoPointers == 0
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return
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}
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