initial import

core/stat/internal/cgroup_linux.go

@@ -0,0 +1,168 @@
+package internal
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+
+	"zero/core/iox"
+	"zero/core/lang"
+)
+
+const cgroupDir = "/sys/fs/cgroup"
+
+type cgroup struct {
+	cgroups map[string]string
+}
+
+func (c *cgroup) acctUsageAllCpus() (uint64, error) {
+	data, err := iox.ReadText(path.Join(c.cgroups["cpuacct"], "cpuacct.usage"))
+	if err != nil {
+		return 0, err
+	}
+
+	return parseUint(string(data))
+}
+
+func (c *cgroup) acctUsagePerCpu() ([]uint64, error) {
+	data, err := iox.ReadText(path.Join(c.cgroups["cpuacct"], "cpuacct.usage_percpu"))
+	if err != nil {
+		return nil, err
+	}
+
+	var usage []uint64
+	for _, v := range strings.Fields(string(data)) {
+		u, err := parseUint(v)
+		if err != nil {
+			return nil, err
+		}
+
+		usage = append(usage, u)
+	}
+
+	return usage, nil
+}
+
+func (c *cgroup) cpuQuotaUs() (int64, error) {
+	data, err := iox.ReadText(path.Join(c.cgroups["cpu"], "cpu.cfs_quota_us"))
+	if err != nil {
+		return 0, err
+	}
+
+	return strconv.ParseInt(string(data), 10, 64)
+}
+
+func (c *cgroup) cpuPeriodUs() (uint64, error) {
+	data, err := iox.ReadText(path.Join(c.cgroups["cpu"], "cpu.cfs_period_us"))
+	if err != nil {
+		return 0, err
+	}
+
+	return parseUint(string(data))
+}
+
+func (c *cgroup) cpus() ([]uint64, error) {
+	data, err := iox.ReadText(path.Join(c.cgroups["cpuset"], "cpuset.cpus"))
+	if err != nil {
+		return nil, err
+	}
+
+	return parseUints(string(data))
+}
+
+func currentCgroup() (*cgroup, error) {
+	cgroupFile := fmt.Sprintf("/proc/%d/cgroup", os.Getpid())
+	lines, err := iox.ReadTextLines(cgroupFile, iox.WithoutBlank())
+	if err != nil {
+		return nil, err
+	}
+
+	cgroups := make(map[string]string)
+	for _, line := range lines {
+		cols := strings.Split(line, ":")
+		if len(cols) != 3 {
+			return nil, fmt.Errorf("invalid cgroup line: %s", line)
+		}
+
+		subsys := cols[1]
+		// only read cpu staff
+		if !strings.HasPrefix(subsys, "cpu") {
+			continue
+		}
+
+		cgroups[subsys] = path.Join(cgroupDir, subsys)
+		if strings.Contains(subsys, ",") {
+			for _, k := range strings.Split(subsys, ",") {
+				cgroups[k] = path.Join(cgroupDir, k)
+			}
+		}
+	}
+
+	return &cgroup{
+		cgroups: cgroups,
+	}, nil
+}
+
+func parseUint(s string) (uint64, error) {
+	v, err := strconv.ParseInt(s, 10, 64)
+	if err != nil {
+		if err.(*strconv.NumError).Err == strconv.ErrRange {
+			return 0, nil
+		} else {
+			return 0, fmt.Errorf("cgroup: bad int format: %s", s)
+		}
+	} else {
+		if v < 0 {
+			return 0, nil
+		} else {
+			return uint64(v), nil
+		}
+	}
+}
+
+func parseUints(val string) ([]uint64, error) {
+	if val == "" {
+		return nil, nil
+	}
+
+	ints := make(map[uint64]lang.PlaceholderType)
+	cols := strings.Split(val, ",")
+	for _, r := range cols {
+		if strings.Contains(r, "-") {
+			fields := strings.SplitN(r, "-", 2)
+			min, err := parseUint(fields[0])
+			if err != nil {
+				return nil, fmt.Errorf("cgroup: bad int list format: %s", val)
+			}
+
+			max, err := parseUint(fields[1])
+			if err != nil {
+				return nil, fmt.Errorf("cgroup: bad int list format: %s", val)
+			}
+
+			if max < min {
+				return nil, fmt.Errorf("cgroup: bad int list format: %s", val)
+			}
+
+			for i := min; i <= max; i++ {
+				ints[i] = lang.Placeholder
+			}
+		} else {
+			v, err := parseUint(r)
+			if err != nil {
+				return nil, err
+			}
+
+			ints[v] = lang.Placeholder
+		}
+	}
+
+	var sets []uint64
+	for k := range ints {
+		sets = append(sets, k)
+	}
+
+	return sets, nil
+}