Merge pull request #376 from ContinuumLLC/win_percpu_feature

Windows: Read processor performance metrics overall, per cpu and per core

cpu/cpu_windows.go

@@ -22,10 +22,34 @@ type Win32_Processor struct {
 	MaxClockSpeed             uint32
 }
 
-// TODO: Get percpu
+// Win32_PerfFormattedData_Counters_ProcessorInformation stores instance value of the perf counters
+type Win32_PerfFormattedData_Counters_ProcessorInformation struct {
+	Name                  string
+	PercentDPCTime        uint64
+	PercentIdleTime       uint64
+	PercentUserTime       uint64
+	PercentProcessorTime  uint64
+	PercentInterruptTime  uint64
+	PercentPriorityTime   uint64
+	PercentPrivilegedTime uint64
+	InterruptsPerSec      uint32
+	ProcessorFrequency    uint32
+	DPCRate               uint32
+}
+
+// Win32_PerfFormattedData_PerfOS_System struct to have count of processes and processor queue length
+type Win32_PerfFormattedData_PerfOS_System struct {
+	Processes            uint32
+	ProcessorQueueLength uint32
+}
+
+// Times returns times stat per cpu and combined for all CPUs
 func Times(percpu bool) ([]TimesStat, error) {
-	var ret []TimesStat
+	if percpu {
+		return perCPUTimes()
+	}
 
+	var ret []TimesStat
 	var lpIdleTime common.FILETIME
 	var lpKernelTime common.FILETIME
 	var lpUserTime common.FILETIME
@@ -83,3 +107,41 @@ func Info() ([]InfoStat, error) {
 
 	return ret, nil
 }
+
+// PerfInfo returns the performance counter's instance value for ProcessorInformation.
+// Name property is the key by which overall, per cpu and per core metric is known.
+func PerfInfo() ([]Win32_PerfFormattedData_Counters_ProcessorInformation, error) {
+	var ret []Win32_PerfFormattedData_Counters_ProcessorInformation
+	q := wmi.CreateQuery(&ret, "")
+	err := wmi.Query(q, &ret)
+	return ret, err
+}
+
+// ProcInfo returns processes count and processor queue length in the system.
+// There is a single queue for processor even on multiprocessors systems.
+func ProcInfo() ([]Win32_PerfFormattedData_PerfOS_System, error) {
+	var ret []Win32_PerfFormattedData_PerfOS_System
+	q := wmi.CreateQuery(&ret, "")
+	err := wmi.Query(q, &ret)
+	return ret, err
+}
+
+// perCPUTimes returns times stat per cpu, per core and overall for all CPUs
+func perCPUTimes() ([]TimesStat, error) {
+	var ret []TimesStat
+	stats, err := PerfInfo()
+	if err != nil {
+		return nil, err
+	}
+	for _, v := range stats {
+		c := TimesStat{
+			CPU:    v.Name,
+			User:   float64(v.PercentUserTime),
+			System: float64(v.PercentPrivilegedTime),
+			Idle:   float64(v.PercentIdleTime),
+			Irq:    float64(v.PercentInterruptTime),
+		}
+		ret = append(ret, c)
+	}
+	return ret, nil
+}