DispatchQueue总结→任务替换（Swift）

// Before
DispatchQueue.main.sync {
  print("1")
}
print("2")

// After
Task {
  await MainActor.run {
    print("1")
  }
  print("2")
}

// Before
DispatchQueue.main.async {
  print("1")
}
print("2")

// After
Task.detached { @MainActor in
  print("1")
}
print("2")

// このように書くことのほうが多い
- Task.detached { @MainActor in
+ Task { @MainActor in
  print("1")
}
print("2")

// Before
let group = DispatchGroup()
let queue1 = DispatchQueue(label: "com.example.myqueue1")
let queue2 = DispatchQueue(label: "com.example.myqueue2")
let queue3 = DispatchQueue(label: "com.example.myqueue3")

queue1.async(group: group) {
  print("1")
}
queue2.async(group: group) {
  print("2")
}
queue3.async(group: group) {
  print("3")
}

group.notify(queue: .main) {
  print("4")
}

// After
async let queue1: Void = printAsync("1")
async let queue2: Void = printAsync("2")
async let queue3: Void = printAsync("3")

_ = await (queue1, queue2, queue3)

print("4")

private func printAsync(_ text: String) async {
  print(text)
}

// Before
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(100)) {
  // ...
}

// After
Task {
  // iOS 13.0+
  try await Task.sleep(nanoseconds: 100_000_000)

  // iOS 16.0+
  try await Task.sleep(for: .nanoseconds(100_000_000))
  try await Task.sleep(for: .microseconds(100_000))
  try await Task.sleep(for: .milliseconds(100))
  try await Task.sleep(for: .seconds(0.1))
  // ...
}