github.com/gmax0/go-ethereum@v1.9.7/common/fdlimit/fdlimit_windows.go (about)

     1  // Copyright 2018 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum 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-ethereum 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-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package fdlimit
    18  
    19  import "fmt"
    20  
    21  // hardlimit is the number of file descriptors allowed at max by the kernel.
    22  const hardlimit = 16384
    23  
    24  // Raise tries to maximize the file descriptor allowance of this process
    25  // to the maximum hard-limit allowed by the OS.
    26  func Raise(max uint64) (uint64, error) {
    27  	// This method is NOP by design:
    28  	//  * Linux/Darwin counterparts need to manually increase per process limits
    29  	//  * On Windows Go uses the CreateFile API, which is limited to 16K files, non
    30  	//    changeable from within a running process
    31  	// This way we can always "request" raising the limits, which will either have
    32  	// or not have effect based on the platform we're running on.
    33  	if max > hardlimit {
    34  		return hardlimit, fmt.Errorf("file descriptor limit (%d) reached", hardlimit)
    35  	}
    36  	return max, nil
    37  }
    38  
    39  // Current retrieves the number of file descriptors allowed to be opened by this
    40  // process.
    41  func Current() (int, error) {
    42  	// Please see Raise for the reason why we use hard coded 16K as the limit
    43  	return hardlimit, nil
    44  }
    45  
    46  // Maximum retrieves the maximum number of file descriptors this process is
    47  // allowed to request for itself.
    48  func Maximum() (int, error) {
    49  	return Current()
    50  }