prometheus/util/runtime/limits_default.go

53 lines
1.7 KiB
Go

// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build !windows
// +build !windows
package runtime
import (
"fmt"
"math"
"syscall"
)
// syscall.RLIM_INFINITY is a constant.
// Its type is int on most architectures but there are exceptions such as loong64.
// Uniform it to uint accorind to the standard.
// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_resource.h.html
var unlimited uint64 = syscall.RLIM_INFINITY & math.MaxUint64
func limitToString(v uint64, unit string) string {
if v == unlimited {
return "unlimited"
}
return fmt.Sprintf("%d%s", v, unit)
}
func getLimits(resource int, unit string) string {
rlimit := syscall.Rlimit{}
err := syscall.Getrlimit(resource, &rlimit)
if err != nil {
panic("syscall.Getrlimit failed: " + err.Error())
}
// rlimit.Cur and rlimit.Max are int64 on some platforms, such as dragonfly.
// We need to cast them explicitly to uint64.
return fmt.Sprintf("(soft=%s, hard=%s)", limitToString(uint64(rlimit.Cur), unit), limitToString(uint64(rlimit.Max), unit)) //nolint:unconvert
}
// FdLimits returns the soft and hard limits for file descriptors.
func FdLimits() string {
return getLimits(syscall.RLIMIT_NOFILE, "")
}