client_golang/prometheus/process_collector_darwin.go

148 lines
4.6 KiB
Go

// Copyright 2024 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.
package prometheus
import (
"errors"
"fmt"
"os"
"syscall"
"time"
"golang.org/x/sys/unix"
)
// notImplementedErr is returned by stub functions that replace cgo functions, when cgo
// isn't available.
var notImplementedErr = errors.New("not implemented")
type memoryInfo struct {
vsize uint64 // Virtual memory size in bytes
rss uint64 // Resident memory size in bytes
}
func canCollectProcess() bool {
return true
}
func getSoftLimit(which int) (uint64, error) {
rlimit := syscall.Rlimit{}
if err := syscall.Getrlimit(which, &rlimit); err != nil {
return 0, err
}
return rlimit.Cur, nil
}
func getOpenFileCount() (float64, error) {
// Alternately, the undocumented proc_pidinfo(PROC_PIDLISTFDS) can be used to
// return a list of open fds, but that requires a way to call C APIs. The
// benefits, however, include fewer system calls and not failing when at the
// open file soft limit.
if dir, err := os.Open("/dev/fd"); err != nil {
return 0.0, err
} else {
defer dir.Close()
// Avoid ReadDir(), as it calls stat(2) on each descriptor. Not only is
// that info not used, but KQUEUE descriptors fail stat(2), which causes
// the whole method to fail.
if names, err := dir.Readdirnames(0); err != nil {
return 0.0, err
} else {
// Subtract 1 to ignore the open /dev/fd descriptor above.
return float64(len(names) - 1), nil
}
}
}
// describe returns all descriptions of the collector for Darwin.
// Ensure that this list of descriptors is kept in sync with the metrics collected
// in the processCollect method. Any changes to the metrics in processCollect
// (such as adding or removing metrics) should be reflected in this list of descriptors.
func (c *processCollector) describe(ch chan<- *Desc) {
ch <- c.cpuTotal
ch <- c.openFDs
ch <- c.maxFDs
ch <- c.maxVsize
ch <- c.startTime
/* the process could be collected but not implemented yet
ch <- c.rss
ch <- c.vsize
ch <- c.inBytes
ch <- c.outBytes
*/
}
func (c *processCollector) processCollect(ch chan<- Metric) {
if procs, err := unix.SysctlKinfoProcSlice("kern.proc.pid", os.Getpid()); err == nil {
if len(procs) == 1 {
startTime := float64(procs[0].Proc.P_starttime.Nano() / 1e9)
ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
} else {
err = fmt.Errorf("sysctl() returned %d proc structs (expected 1)", len(procs))
c.reportError(ch, c.startTime, err)
}
} else {
c.reportError(ch, c.startTime, err)
}
// The proc structure returned by kern.proc.pid above has an Rusage member,
// but it is not filled in, so it needs to be fetched by getrusage(2). For
// that call, the UTime, STime, and Maxrss members are filled out, but not
// Ixrss, Idrss, or Isrss for the memory usage. Memory stats will require
// access to the C API to call task_info(TASK_BASIC_INFO).
rusage := unix.Rusage{}
if err := unix.Getrusage(syscall.RUSAGE_SELF, &rusage); err == nil {
cpuTime := time.Duration(rusage.Stime.Nano() + rusage.Utime.Nano()).Seconds()
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, cpuTime)
} else {
c.reportError(ch, c.cpuTotal, err)
}
if memInfo, err := getMemory(); err == nil {
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(memInfo.rss))
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(memInfo.vsize))
} else if !errors.Is(err, notImplementedErr) {
// Don't report an error when support is not compiled in.
c.reportError(ch, c.rss, err)
c.reportError(ch, c.vsize, err)
}
if fds, err := getOpenFileCount(); err == nil {
ch <- MustNewConstMetric(c.openFDs, GaugeValue, fds)
} else {
c.reportError(ch, c.openFDs, err)
}
if openFiles, err := getSoftLimit(syscall.RLIMIT_NOFILE); err == nil {
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(openFiles))
} else {
c.reportError(ch, c.maxFDs, err)
}
if addressSpace, err := getSoftLimit(syscall.RLIMIT_AS); err == nil {
ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(addressSpace))
} else {
c.reportError(ch, c.maxVsize, err)
}
// TODO: socket(PF_SYSTEM) to fetch "com.apple.network.statistics" might
// be able to get the per-process network send/receive counts.
}