github.com/bhojpur/cache@v0.0.4/pkg/memory/mlock_unix.go (about)

     1  //go:build !windows
     2  // +build !windows
     3  
     4  package memory
     5  
     6  // Copyright (c) 2018 Bhojpur Consulting Private Limited, India. All rights reserved.
     7  
     8  // Permission is hereby granted, free of charge, to any person obtaining a copy
     9  // of this software and associated documentation files (the "Software"), to deal
    10  // in the Software without restriction, including without limitation the rights
    11  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    12  // copies of the Software, and to permit persons to whom the Software is
    13  // furnished to do so, subject to the following conditions:
    14  
    15  // The above copyright notice and this permission notice shall be included in
    16  // all copies or substantial portions of the Software.
    17  
    18  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    19  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    20  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    21  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    22  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    23  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    24  // THE SOFTWARE.
    25  
    26  import "golang.org/x/sys/unix"
    27  
    28  // mlock locks memory of db file
    29  func mlock(db *DB, fileSize int) error {
    30  	sizeToLock := fileSize
    31  	if sizeToLock > db.datasz {
    32  		// Can't lock more than mmaped slice
    33  		sizeToLock = db.datasz
    34  	}
    35  	if err := unix.Mlock(db.dataref[:sizeToLock]); err != nil {
    36  		return err
    37  	}
    38  	return nil
    39  }
    40  
    41  //munlock unlocks memory of db file
    42  func munlock(db *DB, fileSize int) error {
    43  	if db.dataref == nil {
    44  		return nil
    45  	}
    46  
    47  	sizeToUnlock := fileSize
    48  	if sizeToUnlock > db.datasz {
    49  		// Can't unlock more than mmaped slice
    50  		sizeToUnlock = db.datasz
    51  	}
    52  
    53  	if err := unix.Munlock(db.dataref[:sizeToUnlock]); err != nil {
    54  		return err
    55  	}
    56  	return nil
    57  }