mirror of
https://github.com/golang/go
synced 2024-11-19 17:14:44 -07:00
2b74de3ed9
Change-Id: I37706ff0a3486827c5b072c95ad890ea87ede847 Reviewed-on: https://go-review.googlesource.com/28210 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
27 lines
855 B
Go
27 lines
855 B
Go
// Copyright 2015 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 runtime
|
|
|
|
var randomNumber uint32
|
|
|
|
func archauxv(tag, val uintptr) {
|
|
switch tag {
|
|
case _AT_RANDOM:
|
|
// sysargs filled in startupRandomData, but that
|
|
// pointer may not be word aligned, so we must treat
|
|
// it as a byte array.
|
|
randomNumber = uint32(startupRandomData[4]) | uint32(startupRandomData[5])<<8 |
|
|
uint32(startupRandomData[6])<<16 | uint32(startupRandomData[7])<<24
|
|
}
|
|
}
|
|
|
|
//go:nosplit
|
|
func cputicks() int64 {
|
|
// Currently cputicks() is used in blocking profiler and to seed fastrand().
|
|
// nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
|
|
// randomNumber provides better seeding of fastrand.
|
|
return nanotime() + int64(randomNumber)
|
|
}
|