github.com/SmartMeshFoundation/Spectrum@v0.0.0-20220621030607-452a266fee1e/cmd/utils/fdlimit_freebsd.go (about)

     1  // Copyright 2016 The Spectrum Authors
     2  // This file is part of Spectrum.
     3  //
     4  // Spectrum is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // Spectrum is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU General Public License
    15  // along with Spectrum. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // +build freebsd
    18  
    19  package utils
    20  
    21  import "syscall"
    22  
    23  // This file is largely identical to fdlimit_unix.go,
    24  // but Rlimit fields have type int64 on FreeBSD so it needs
    25  // an extra conversion.
    26  
    27  // raiseFdLimit tries to maximize the file descriptor allowance of this process
    28  // to the maximum hard-limit allowed by the OS.
    29  func raiseFdLimit(max uint64) error {
    30  	// Get the current limit
    31  	var limit syscall.Rlimit
    32  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    33  		return err
    34  	}
    35  	// Try to update the limit to the max allowance
    36  	limit.Cur = limit.Max
    37  	if limit.Cur > int64(max) {
    38  		limit.Cur = int64(max)
    39  	}
    40  	if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    41  		return err
    42  	}
    43  	return nil
    44  }
    45  
    46  // getFdLimit retrieves the number of file descriptors allowed to be opened by this
    47  // process.
    48  func getFdLimit() (int, error) {
    49  	var limit syscall.Rlimit
    50  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    51  		return 0, err
    52  	}
    53  	return int(limit.Cur), nil
    54  }
    55  
    56  // getFdMaxLimit retrieves the maximum number of file descriptors this process is
    57  // allowed to request for itself.
    58  func getFdMaxLimit() (int, error) {
    59  	var limit syscall.Rlimit
    60  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    61  		return 0, err
    62  	}
    63  	return int(limit.Max), nil
    64  }