4 files changed, 170 insertions, 1 deletions

diff --git a/README.md b/README.md
index 0c4822f..9d742d8 100644
--- a/README.md
+++ b/README.md
@@ -26,6 +26,7 @@ cpu | Exposes CPU statistics | Darwin, Dragonfly, FreeBSD
 diskstats | Exposes disk I/O statistics from `/proc/diskstats`. | Linux
 edac | Exposes error detection and correction statistics. | Linux
 entropy | Exposes available entropy. | Linux
+exec | Exposes execution statistics. | Dragonfly, FreeBSD
 filefd | Exposes file descriptor statistics from `/proc/sys/fs/file-nr`. | Linux
 filesystem | Exposes filesystem statistics, such as disk space used. | Darwin, Dragonfly, FreeBSD, Linux, OpenBSD
 hwmon | Expose hardware monitoring and sensor data from `/sys/class/hwmon/`. | Linux
diff --git a/collector/exec_bsd.go b/collector/exec_bsd.go
new file mode 100644
index 0000000..0c79458
--- /dev/null
+++ b/collector/exec_bsd.go
@@ -0,0 +1,98 @@
+// 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.
+
+// +build freebsd dragonfly
+// +build !noexec
+
+package collector
+
+import (
+        "github.com/prometheus/client_golang/prometheus"
+)
+
+type execCollector struct {
+        sysctls []bsdSysctl
+}
+
+func init() {
+        Factories["exec"] = NewExecCollector
+}
+
+// NewExecCollector returns a new Collector exposing system execution statistics
+func NewExecCollector() (Collector, error) {
+        // From sys/vm/vm_meter.c:
+        // All are of type CTLTYPE_UINT.
+        //
+        // vm.stats.sys.v_swtch: Context switches
+        // vm.stats.sys.v_trap: Traps
+        // vm.stats.sys.v_syscall: System calls
+        // vm.stats.sys.v_intr: Device interrupts
+        // vm.stats.sys.v_soft: Software interrupts
+        // vm.stats.vm.v_forks: Number of fork() calls
+
+        return &execCollector{
+                sysctls: []bsdSysctl{
+                        {
+                                name:        "context_switches_total",
+                                description: "Context switches since system boot.  Resets at architeture unsigned integer.",
+                                mib:         "vm.stats.sys.v_swtch",
+                        },
+                        {
+                                name:        "traps_total",
+                                description: "Traps since system boot.  Resets at architeture unsigned integer.",
+                                mib:         "vm.stats.sys.v_trap",
+                        },
+                        {
+                                name:        "system_calls_total",
+                                description: "System calls since system boot.  Resets at architeture unsigned integer.",
+                                mib:         "vm.stats.sys.v_syscall",
+                        },
+                        {
+                                name:        "device_interrupts_total",
+                                description: "Device interrupts since system boot.  Resets at architeture unsigned integer.",
+                                mib:         "vm.stats.sys.v_intr",
+                        },
+                        {
+                                name:        "software_interrupts_total",
+                                description: "Software interrupts since system boot.  Resets at architeture unsigned integer.",
+                                mib:         "vm.stats.sys.v_soft",
+                        },
+                        {
+                                name:        "forks_total",
+                                description: "Number of fork() calls since system boot.  Resets at architeture unsigned integer.",
+                                mib:         "vm.stats.vm.v_forks",
+                        },
+                },
+        }, nil
+}
+
+// Update pushes exec statistics onto ch
+func (c *execCollector) Update(ch chan<- prometheus.Metric) (err error) {
+        for _, m := range c.sysctls {
+                v, err := m.Value()
+                if err != nil {
+                        return err
+                }
+
+                // We "know" all of our sysctls are CounterValues, let's skip
+                // parsing them
+                ch <- prometheus.MustNewConstMetric(
+                        prometheus.NewDesc(
+                                prometheus.BuildFQName(Namespace, "exec", m.name),
+                                m.description,
+                                nil, nil,
+                        ), prometheus.CounterValue, v)
+        }
+
+        return nil
+}
diff --git a/collector/sysctl_bsd.go b/collector/sysctl_bsd.go
new file mode 100644
index 0000000..fcb8af5
--- /dev/null
+++ b/collector/sysctl_bsd.go
@@ -0,0 +1,70 @@
+// 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.
+
+// +build freebsd dragonfly
+// +build !nomeminfo
+
+package collector
+
+import (
+        "github.com/prometheus/client_golang/prometheus"
+        "golang.org/x/sys/unix"
+)
+
+type bsdSysctlType uint8
+
+// BSD-specific sysctl value types.  There is an impedience mismatch between
+// native C types, e.g. int vs long, and the golang unix.Sysctl variables
+
+const (
+        // Default to uint32.
+        bsdSysctlTypeUint32 bsdSysctlType = iota
+        bsdSysctlTypeUint64
+)
+
+// Contains all the info needed to map a single bsd-sysctl to a prometheus value.
+type bsdSysctl struct {
+        // Prometheus name
+        name string
+
+        // Simple prometheus description
+        description string
+
+        // Prometheus type
+        valueType prometheus.ValueType
+
+        // Sysctl name
+        mib string
+
+        // Sysctl data-type
+        dataType bsdSysctlType
+}
+
+func (b bsdSysctl) Value() (float64, error) {
+        var tmp32 uint32
+        var tmp64 uint64
+        var err error
+
+        switch b.dataType {
+        case bsdSysctlTypeUint32:
+                tmp32, err = unix.SysctlUint32(b.mib)
+                tmp64 = uint64(tmp32)
+        case bsdSysctlTypeUint64:
+                tmp64, err = unix.SysctlUint64(b.mib)
+        }
+        if err != nil {
+                return 0, err
+        }
+
+        return float64(tmp64), nil
+}
diff --git a/node_exporter.go b/node_exporter.go
index ec69c05..1a505cf 100644
--- a/node_exporter.go
+++ b/node_exporter.go
@@ -32,7 +32,7 @@ import (
 )
 
 const (
-        defaultCollectors = "conntrack,cpu,diskstats,entropy,edac,filefd,filesystem,hwmon,infiniband,loadavg,mdadm,meminfo,netdev,netstat,sockstat,stat,textfile,time,uname,vmstat,wifi,zfs"
+        defaultCollectors = "conntrack,cpu,diskstats,entropy,edac,exec,filefd,filesystem,hwmon,infiniband,loadavg,mdadm,meminfo,netdev,netstat,sockstat,stat,textfile,time,uname,vmstat,wifi,zfs"
 )
 
 var (