github.com/Heebron/moby@v0.0.0-20221111184709-6eab4f55faf7/pkg/archive/diff_unix.go (about)

     1  //go:build !windows
     2  // +build !windows
     3  
     4  package archive
     5  
     6  import "golang.org/x/sys/unix"
     7  
     8  // overrideUmask sets current process's file mode creation mask to newmask
     9  // and returns a function to restore it.
    10  //
    11  // WARNING for readers stumbling upon this code. Changing umask in a multi-
    12  // threaded environment isn't safe. Don't use this without understanding the
    13  // risks, and don't export this function for others to use (we shouldn't even
    14  // be using this ourself).
    15  //
    16  // FIXME(thaJeztah): we should get rid of these hacks if possible.
    17  func overrideUmask(newMask int) func() {
    18  	oldMask := unix.Umask(newMask)
    19  	return func() {
    20  		unix.Umask(oldMask)
    21  	}
    22  }