github.com/core-coin/go-core/v2@v2.1.9/common/fdlimit/fdlimit_bsd.go (about)

     1  // Copyright 2016 by the Authors
     2  // This file is part of the go-core library.
     3  //
     4  // The go-core library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser 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  // The go-core library 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 Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-core library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  //go:build freebsd || dragonfly
    18  // +build freebsd dragonfly
    19  
    20  package fdlimit
    21  
    22  import "syscall"
    23  
    24  // This file is largely identical to fdlimit_unix.go,
    25  // but Rlimit fields have type int64 on *BSD so it needs
    26  // an extra conversion.
    27  
    28  // Raise tries to maximize the file descriptor allowance of this process
    29  // to the maximum hard-limit allowed by the OS.
    30  func Raise(max uint64) (uint64, error) {
    31  	// Get the current limit
    32  	var limit syscall.Rlimit
    33  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    34  		return 0, err
    35  	}
    36  	// Try to update the limit to the max allowance
    37  	limit.Cur = limit.Max
    38  	if limit.Cur > int64(max) {
    39  		limit.Cur = int64(max)
    40  	}
    41  	if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    42  		return 0, err
    43  	}
    44  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    45  		return 0, err
    46  	}
    47  	return uint64(limit.Cur), nil
    48  }
    49  
    50  // Current retrieves the number of file descriptors allowed to be opened by this
    51  // process.
    52  func Current() (int, error) {
    53  	var limit syscall.Rlimit
    54  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    55  		return 0, err
    56  	}
    57  	return int(limit.Cur), nil
    58  }
    59  
    60  // Maximum retrieves the maximum number of file descriptors this process is
    61  // allowed to request for itself.
    62  func Maximum() (int, error) {
    63  	var limit syscall.Rlimit
    64  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
    65  		return 0, err
    66  	}
    67  	return int(limit.Max), nil
    68  }