36 lines
991 B
Go
36 lines
991 B
Go
// Copyright (C) 2018 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at https://mozilla.org/MPL/2.0/.
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//go:build (!windows && !linux) || android
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// +build !windows,!linux android
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package osutil
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import (
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"syscall"
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"github.com/pkg/errors"
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)
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// SetLowPriority lowers the process CPU scheduling priority, and possibly
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// I/O priority depending on the platform and OS.
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func SetLowPriority() error {
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// Process zero is "self", niceness value 9 is something between 0
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// (default) and 19 (worst priority).
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const (
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pidSelf = 0
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wantNiceLevel = 9
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)
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if cur, err := syscall.Getpriority(syscall.PRIO_PROCESS, pidSelf); err == nil && cur >= wantNiceLevel {
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// We're done here.
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return nil
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}
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err := syscall.Setpriority(syscall.PRIO_PROCESS, pidSelf, wantNiceLevel)
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return errors.Wrap(err, "set niceness") // wraps nil as nil
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}
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