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| 1 | +// Copyright 2024 The Prometheus Authors |
| 2 | +// Licensed under the Apache License, Version 2.0 (the "License"); |
| 3 | +// you may not use this file except in compliance with the License. |
| 4 | +// You may obtain a copy of the License at |
| 5 | +// |
| 6 | +// http://www.apache.org/licenses/LICENSE-2.0 |
| 7 | +// |
| 8 | +// Unless required by applicable law or agreed to in writing, software |
| 9 | +// distributed under the License is distributed on an "AS IS" BASIS, |
| 10 | +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 11 | +// See the License for the specific language governing permissions and |
| 12 | +// limitations under the License. |
| 13 | + |
| 14 | +package prometheus |
| 15 | + |
| 16 | +import ( |
| 17 | + "fmt" |
| 18 | + "golang.org/x/sys/unix" |
| 19 | + "os" |
| 20 | + "syscall" |
| 21 | + "time" |
| 22 | +) |
| 23 | + |
| 24 | +func canCollectProcess() bool { |
| 25 | + return true |
| 26 | +} |
| 27 | + |
| 28 | +func getSoftLimit(which int) (uint64, error) { |
| 29 | + rlimit := syscall.Rlimit{} |
| 30 | + |
| 31 | + if err := syscall.Getrlimit(which, &rlimit); err != nil { |
| 32 | + return 0, err |
| 33 | + } |
| 34 | + |
| 35 | + return rlimit.Cur, nil |
| 36 | +} |
| 37 | + |
| 38 | +func getOpenFileCount() (float64, error) { |
| 39 | + // Alternately, the undocumented proc_pidinfo(PROC_PIDLISTFDS) can be used to |
| 40 | + // return a list of open fds, but that requires a way to call C APIs. The |
| 41 | + // benefits, however, include fewer system calls and not failing when at the |
| 42 | + // open file soft limit. |
| 43 | + |
| 44 | + if dir, err := os.Open("/dev/fd"); err != nil { |
| 45 | + return 0.0, err |
| 46 | + } else { |
| 47 | + defer dir.Close() |
| 48 | + |
| 49 | + // Avoid ReadDir(), as it calls stat(2) on each descriptor. Not only is |
| 50 | + // that info not used, but KQUEUE descriptors fail stat(2), which causes |
| 51 | + // the whole method to fail. |
| 52 | + if names, err := dir.Readdirnames(0); err != nil { |
| 53 | + return 0.0, err |
| 54 | + } else { |
| 55 | + // Subtract 1 to ignore the open /dev/fd descriptor above. |
| 56 | + return float64(len(names) - 1), nil |
| 57 | + } |
| 58 | + } |
| 59 | +} |
| 60 | + |
| 61 | +func (c *processCollector) processCollect(ch chan<- Metric) { |
| 62 | + if procs, err := unix.SysctlKinfoProcSlice("kern.proc.pid", os.Getpid()); err == nil { |
| 63 | + if len(procs) == 1 { |
| 64 | + startTime := float64(procs[0].Proc.P_starttime.Nano() / 1e9) |
| 65 | + ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime) |
| 66 | + } else { |
| 67 | + err = fmt.Errorf("sysctl() returned %d proc structs (expected 1)", len(procs)) |
| 68 | + c.reportError(ch, c.startTime, err) |
| 69 | + } |
| 70 | + } else { |
| 71 | + c.reportError(ch, c.startTime, err) |
| 72 | + } |
| 73 | + |
| 74 | + // The proc structure returned by kern.proc.pid above has an Rusage member, |
| 75 | + // but it is not filled in, so it needs to be fetched by getrusage(2). For |
| 76 | + // that call, the UTime, STime, and Maxrss members are filled out, but not |
| 77 | + // Ixrss, Idrss, or Isrss for the memory usage. Memory stats will require |
| 78 | + // access to the C API to call task_info(TASK_BASIC_INFO). |
| 79 | + rusage := unix.Rusage{} |
| 80 | + |
| 81 | + if err := unix.Getrusage(syscall.RUSAGE_SELF, &rusage); err == nil { |
| 82 | + cpuTime := time.Duration(rusage.Stime.Nano() + rusage.Utime.Nano()).Seconds() |
| 83 | + ch <- MustNewConstMetric(c.cpuTotal, CounterValue, cpuTime) |
| 84 | + } else { |
| 85 | + c.reportError(ch, c.cpuTotal, err) |
| 86 | + } |
| 87 | + |
| 88 | + // TODO: publish c.vsize and c.rss values |
| 89 | + |
| 90 | + if fds, err := getOpenFileCount(); err == nil { |
| 91 | + ch <- MustNewConstMetric(c.openFDs, GaugeValue, fds) |
| 92 | + } else { |
| 93 | + c.reportError(ch, c.openFDs, err) |
| 94 | + } |
| 95 | + |
| 96 | + if openFiles, err := getSoftLimit(syscall.RLIMIT_NOFILE); err == nil { |
| 97 | + ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(openFiles)) |
| 98 | + } else { |
| 99 | + c.reportError(ch, c.maxFDs, err) |
| 100 | + } |
| 101 | + |
| 102 | + if addressSpace, err := getSoftLimit(syscall.RLIMIT_AS); err == nil { |
| 103 | + ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(addressSpace)) |
| 104 | + } else { |
| 105 | + c.reportError(ch, c.maxVsize, err) |
| 106 | + } |
| 107 | + |
| 108 | + // TODO: socket(PF_SYSTEM) to fetch "com.apple.network.statistics" might |
| 109 | + // be able to get the per-process network send/receive counts. |
| 110 | +} |
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