go.etcd.io/etcd@v3.3.27+incompatible/pkg/runtime/fds_linux.go (about) 1 // Copyright 2015 The etcd Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // Package runtime implements utility functions for runtime systems. 16 package runtime 17 18 import ( 19 "os" 20 "syscall" 21 ) 22 23 func FDLimit() (uint64, error) { 24 var rlimit syscall.Rlimit 25 if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit); err != nil { 26 return 0, err 27 } 28 return rlimit.Cur, nil 29 } 30 31 func FDUsage() (uint64, error) { 32 return countFiles("/proc/self/fd") 33 } 34 35 // countFiles reads the directory named by dirname and returns the count. 36 // This is same as stdlib "io/ioutil.ReadDir" but without sorting. 37 func countFiles(dirname string) (uint64, error) { 38 f, err := os.Open(dirname) 39 if err != nil { 40 return 0, err 41 } 42 list, err := f.Readdir(-1) 43 f.Close() 44 if err != nil { 45 return 0, err 46 } 47 return uint64(len(list)), nil 48 }