swift-nio/Sources/NIO/FileDescriptor.swift

50 lines
1.9 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
public protocol FileDescriptor {
/// Will be called with the file descriptor if still open, if not it will
/// throw an `IOError`.
///
/// The ownership of the file descriptor must not escape the `body` as it's completely managed by the
/// implementation of the `FileDescriptor` protocol.
///
/// - parameters:
/// - body: The closure to execute if the `FileDescriptor` is still open.
/// - throws: If either the `FileDescriptor` was closed before or the closure throws by itself.
func withUnsafeFileDescriptor<T>(_ body: (CInt) throws -> T) throws -> T
/// `true` if this `FileDescriptor` is open (which means it was not closed yet).
var isOpen: Bool { get }
/// Close this `FileDescriptor`.
func close() throws
}
extension FileDescriptor {
internal static func setNonBlocking(fileDescriptor: CInt) throws {
let flags = try Posix.fcntl(descriptor: fileDescriptor, command: F_GETFL, value: 0)
do {
let ret = try Posix.fcntl(descriptor: fileDescriptor, command: F_SETFL, value: flags | O_NONBLOCK)
assert(ret == 0, "unexpectedly, fcntl(\(fileDescriptor), F_SETFL, \(flags) | O_NONBLOCK) returned \(ret)")
} catch let error as IOError {
if error.errnoCode == EINVAL {
// Darwin seems to sometimes do this despite the docs claiming it can't happen
throw NIOFcntlFailedError()
}
throw error
}
}
}