Add cpu collector for darwin

1 files changed, 119 insertions, 0 deletions

diff --git a/collector/cpu_darwin.go b/collector/cpu_darwin.go
new file mode 100644
index 0000000..174e541
--- /dev/null
+++ b/collector/cpu_darwin.go
@@ -0,0 +1,119 @@
+// Copyright 2016 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.
+
+// Based on gopsutil/cpu/cpu_darwin_cgo.go @ ae251eb which is licensed under
+// BSD. See https://github.com/shirou/gopsutil/blob/master/LICENSE for details.
+
+// +build !nocpu
+
+package collector
+
+import (
+        "bytes"
+        "encoding/binary"
+        "fmt"
+        "strconv"
+        "unsafe"
+
+        "github.com/prometheus/client_golang/prometheus"
+)
+
+/*
+#cgo LDFLAGS:
+#include <stdlib.h>
+#include <sys/sysctl.h>
+#include <sys/mount.h>
+#include <mach/mach_init.h>
+#include <mach/mach_host.h>
+#include <mach/host_info.h>
+#if TARGET_OS_MAC
+#include <libproc.h>
+#endif
+#include <mach/processor_info.h>
+#include <mach/vm_map.h>
+*/
+import "C"
+
+// default value. from time.h
+const ClocksPerSec = float64(128)
+
+type statCollector struct {
+        cpu *prometheus.Desc
+}
+
+func init() {
+        Factories["cpu"] = NewCPUCollector
+}
+
+// Takes a prometheus registry and returns a new Collector exposing
+// CPU stats.
+func NewCPUCollector() (Collector, error) {
+        return &statCollector{
+                cpu: prometheus.NewDesc(
+                        prometheus.BuildFQName(Namespace, "", "cpu"),
+                        "Seconds the cpus spent in each mode.",
+                        []string{"cpu", "mode"}, nil,
+                ),
+        }, nil
+}
+
+func (c *statCollector) Update(ch chan<- prometheus.Metric) error {
+        var (
+                count   C.mach_msg_type_number_t
+                cpuload *C.processor_cpu_load_info_data_t
+                ncpu    C.natural_t
+        )
+
+        status := C.host_processor_info(C.host_t(C.mach_host_self()),
+                C.PROCESSOR_CPU_LOAD_INFO,
+                &ncpu,
+                (*C.processor_info_array_t)(unsafe.Pointer(&cpuload)),
+                &count)
+
+        if status != C.KERN_SUCCESS {
+                return fmt.Errorf("host_processor_info error=%d", status)
+        }
+
+        // jump through some cgo casting hoops and ensure we properly free
+        // the memory that cpuload points to
+        target := C.vm_map_t(C.mach_task_self_)
+        address := C.vm_address_t(uintptr(unsafe.Pointer(cpuload)))
+        defer C.vm_deallocate(target, address, C.vm_size_t(ncpu))
+
+        // the body of struct processor_cpu_load_info
+        // aka processor_cpu_load_info_data_t
+        var cpu_ticks [C.CPU_STATE_MAX]uint32
+
+        // copy the cpuload array to a []byte buffer
+        // where we can binary.Read the data
+        size := int(ncpu) * binary.Size(cpu_ticks)
+        buf := (*[1 << 30]byte)(unsafe.Pointer(cpuload))[:size:size]
+
+        bbuf := bytes.NewBuffer(buf)
+
+        for i := 0; i < int(ncpu); i++ {
+                err := binary.Read(bbuf, binary.LittleEndian, &cpu_ticks)
+                if err != nil {
+                        return err
+                }
+                for k, v := range map[string]int{
+                        "user":   C.CPU_STATE_USER,
+                        "system": C.CPU_STATE_SYSTEM,
+                        "nice":   C.CPU_STATE_NICE,
+                        "idle":   C.CPU_STATE_IDLE,
+                } {
+                        ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, float64(cpu_ticks[v])/ClocksPerSec, "cpu"+strconv.Itoa(i), k)
+                }
+        }
+        return nil
+}