node_exporter/collector/cpu_dragonfly.go

147 lines
3.7 KiB
Go

// Copyright 2015 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.
// +build !nocpu
package collector
import (
"errors"
"fmt"
"strconv"
"strings"
"unsafe"
"github.com/prometheus/client_golang/prometheus"
)
/*
#cgo LDFLAGS:
#include <sys/sysctl.h>
#include <kinfo.h>
#include <stdlib.h>
#include <stdio.h>
int
getCPUTimes(char **cputime) {
size_t len;
// Get number of cpu cores.
int mib[2];
int ncpu;
mib[0] = CTL_HW;
mib[1] = HW_NCPU;
len = sizeof(ncpu);
if (sysctl(mib, 2, &ncpu, &len, NULL, 0)) {
return -1;
}
// The bump on each statclock is
// ((cur_systimer - prev_systimer) * systimer_freq) >> 32
// where
// systimer_freq = sysctl kern.cputimer.freq
long freq;
len = sizeof(freq);
if (sysctlbyname("kern.cputimer.freq", &freq, &len, NULL, 0)) {
return -1;
}
// Get the cpu times.
struct kinfo_cputime cp_t[ncpu];
bzero(cp_t, sizeof(struct kinfo_cputime)*ncpu);
len = sizeof(cp_t[0])*ncpu;
if (sysctlbyname("kern.cputime", &cp_t, &len, NULL, 0)) {
return -1;
}
// string needs to hold (5*ncpu)(uint64_t + char)
// The char is the space between values.
int cputime_size = (sizeof(uint64_t)+sizeof(char))*(5*ncpu);
*cputime = (char *) malloc(cputime_size);
bzero(*cputime, cputime_size);
uint64_t user, nice, sys, intr, idle;
user = nice = sys = intr = idle = 0;
for (int i = 0; i < ncpu; ++i) {
user = ((double) cp_t[i].cp_user) / freq;
nice = ((double) cp_t[i].cp_nice) / freq;
sys = ((double) cp_t[i].cp_sys) / freq;
intr = ((double) cp_t[i].cp_intr) / freq;
idle = ((double) cp_t[i].cp_idle) / freq;
sprintf(*cputime + strlen(*cputime), "%llu %llu %llu %llu %llu ", user, nice, sys, intr, idle );
}
return 0;
}
*/
import "C"
const maxCPUTimesLen = C.MAXCPU * C.CPUSTATES
type statCollector struct {
cpu *prometheus.Desc
}
func init() {
Factories["cpu"] = NewStatCollector
}
// Takes a prometheus registry and returns a new Collector exposing
// CPU stats.
func NewStatCollector() (Collector, error) {
return &statCollector{
cpu: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, "", "cpu"),
"Seconds the cpus spent in each mode.",
[]string{"cpu", "mode"}, nil,
),
}, nil
}
// Expose CPU stats using sysctl.
func (c *statCollector) Update(ch chan<- prometheus.Metric) error {
// We want time spent per-cpu per CPUSTATE.
// CPUSTATES (number of CPUSTATES) is defined as 5U.
// States: CP_USER | CP_NICE | CP_SYS | CP_IDLE | CP_INTR
//
// Each value is a counter incremented at frequency
// kern.cputimer.freq
//
// Look into sys/kern/kern_clock.c for details.
var cpuTimesC *C.char
var fieldsCount = 5
if C.getCPUTimes(&cpuTimesC) == -1 {
return errors.New("could not retrieve CPU times")
}
cpuTimes := strings.Split(strings.TrimSpace(C.GoString(cpuTimesC)), " ")
C.free(unsafe.Pointer(cpuTimesC))
// Export order: user nice sys intr idle
cpuFields := []string{"user", "nice", "sys", "interrupt", "idle"}
for i, v := range cpuTimes {
cpux := fmt.Sprintf("cpu%d", i/fieldsCount)
value, err := strconv.ParseFloat(v, 64)
if err != nil {
return err
}
ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, value, cpux, cpuFields[i%fieldsCount])
}
return nil
}