github.com/m3db/m3@v1.5.1-0.20231129193456-75a402aa583b/src/x/sync/num_cores_linux.go (about)

     1  //go:build linux
     2  // +build linux
     3  
     4  //
     5  // Copyright (c) 2021  Uber Technologies, Inc.
     6  //
     7  // Permission is hereby granted, free of charge, to any person obtaining a copy
     8  // of this software and associated documentation files (the "Software"), to deal
     9  // in the Software without restriction, including without limitation the rights
    10  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    11  // copies of the Software, and to permit persons to whom the Software is
    12  // furnished to do so, subject to the following conditions:
    13  //
    14  // The above copyright notice and this permission notice shall be included in
    15  // all copies or substantial portions of the Software.
    16  //
    17  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    18  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    19  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    20  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    21  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    22  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    23  // THE SOFTWARE.
    24  
    25  package sync
    26  
    27  import (
    28  	"bufio"
    29  	"os"
    30  	"strings"
    31  )
    32  
    33  func checkNumCores() int {
    34  	f, err := os.Open("/proc/cpuinfo")
    35  	if err != nil {
    36  		return 1
    37  	}
    38  
    39  	n := 0
    40  	scanner := bufio.NewScanner(f)
    41  	for scanner.Scan() {
    42  		if strings.HasPrefix(scanner.Text(), "processor") {
    43  			n++
    44  		}
    45  	}
    46  
    47  	_ = f.Close()
    48  
    49  	if err := scanner.Err(); err != nil {
    50  		return 1
    51  	}
    52  
    53  	return n
    54  }