github.com/m3db/m3@v1.5.0/src/x/sync/num_cores_linux.go (about)

     1  // +build linux
     2  //
     3  // Copyright (c) 2021  Uber Technologies, Inc.
     4  //
     5  // Permission is hereby granted, free of charge, to any person obtaining a copy
     6  // of this software and associated documentation files (the "Software"), to deal
     7  // in the Software without restriction, including without limitation the rights
     8  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     9  // copies of the Software, and to permit persons to whom the Software is
    10  // furnished to do so, subject to the following conditions:
    11  //
    12  // The above copyright notice and this permission notice shall be included in
    13  // all copies or substantial portions of the Software.
    14  //
    15  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    16  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    17  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    18  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    19  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    20  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    21  // THE SOFTWARE.
    22  
    23  package sync
    24  
    25  import (
    26  	"bufio"
    27  	"os"
    28  	"strings"
    29  )
    30  
    31  func checkNumCores() int {
    32  	f, err := os.Open("/proc/cpuinfo")
    33  	if err != nil {
    34  		return 1
    35  	}
    36  
    37  	n := 0
    38  	scanner := bufio.NewScanner(f)
    39  	for scanner.Scan() {
    40  		if strings.HasPrefix(scanner.Text(), "processor") {
    41  			n++
    42  		}
    43  	}
    44  
    45  	_ = f.Close()
    46  
    47  	if err := scanner.Err(); err != nil {
    48  		return 1
    49  	}
    50  
    51  	return n
    52  }