github.com/aigarnetwork/aigar@v0.0.0-20191115204914-d59a6eb70f8e/common/fdlimit/fdlimit_windows.go (about)

     1  //  Copyright 2018 The go-ethereum Authors
     2  //  Copyright 2019 The go-aigar Authors
     3  //  This file is part of the go-aigar library.
     4  //
     5  //  The go-aigar library is free software: you can redistribute it and/or modify
     6  //  it under the terms of the GNU Lesser General Public License as published by
     7  //  the Free Software Foundation, either version 3 of the License, or
     8  //  (at your option) any later version.
     9  //
    10  //  The go-aigar library is distributed in the hope that it will be useful,
    11  //  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  //  GNU Lesser General Public License for more details.
    14  //
    15  //  You should have received a copy of the GNU Lesser General Public License
    16  //  along with the go-aigar library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package fdlimit
    19  
    20  import "fmt"
    21  
    22  // hardlimit is the number of file descriptors allowed at max by the kernel.
    23  const hardlimit = 16384
    24  
    25  // Raise tries to maximize the file descriptor allowance of this process
    26  // to the maximum hard-limit allowed by the OS.
    27  func Raise(max uint64) (uint64, error) {
    28  	// This method is NOP by design:
    29  	//  * Linux/Darwin counterparts need to manually increase per process limits
    30  	//  * On Windows Go uses the CreateFile API, which is limited to 16K files, non
    31  	//    changeable from within a running process
    32  	// This way we can always "request" raising the limits, which will either have
    33  	// or not have effect based on the platform we're running on.
    34  	if max > hardlimit {
    35  		return hardlimit, fmt.Errorf("file descriptor limit (%d) reached", hardlimit)
    36  	}
    37  	return max, nil
    38  }
    39  
    40  // Current retrieves the number of file descriptors allowed to be opened by this
    41  // process.
    42  func Current() (int, error) {
    43  	// Please see Raise for the reason why we use hard coded 16K as the limit
    44  	return hardlimit, nil
    45  }
    46  
    47  // Maximum retrieves the maximum number of file descriptors this process is
    48  // allowed to request for itself.
    49  func Maximum() (int, error) {
    50  	return Current()
    51  }