單一執行緒基本範例
using System;
using System.Threading;
class SingleThread
{
static void Main(string[] args)
{
SingleThread st = new SingleThread();
Thread th = new Thread(new ThreadStart(st.SayHello));
th.Start();
}
public void SayHello()
{
Console.WriteLine("Hello from a single thread.");
}
}
多執行緒同步資料存取
class SyncData
{
int index = 0;
string[] comments = { "一", "二", "三", "四", "五", "六", "七", "八", "九", "十",
"十一", "十二", "十三", "十四", "十五", "十六", "十七", "十八", "十九", "二十" };
public string GetNextComment()
{
lock (this)
{
if (index < comments.Length)
return comments[index++];
return "empty";
}
}
}
class Synchronization
{
SyncData data = new SyncData();
public void GetComments()
{
string comment;
do
{
comment = data.GetNextComment();
Console.WriteLine($"Current Thread: {Thread.CurrentThread.Name}, Comment: {comment}");
} while (comment != "empty");
}
static void Main(string[] args)
{
Synchronization sync = new Synchronization();
Thread t1 = new Thread(new ThreadStart(sync.GetComments)) { Name = "Thread 1" };
Thread t2 = new Thread(new ThreadStart(sync.GetComments)) { Name = "Thread 2" };
Thread t3 = new Thread(new ThreadStart(sync.GetComments)) { Name = "Thread 3" };
t1.Start(); t2.Start(); t3.Start();
}
}
核心概念總結
| 概念 | 說明 |
|---|
| ThreadStart | 無參數無回傳值的委派，指向執行緒進入點方法 |
| lock | 互斥鎖，確保同一時間只有一個執行緒進入關鍵區段 |
| Thread.CurrentThread.Name | 設定/取得執行緒名稱，方便除錯追蹤 |
| Start() | 啟動執行緒，排程執行但不保證立即執行 |
進階建議
- 優先使用
Task / async-await 取代手動管理 Thread
- 共享資料使用
Concurrent 集合或 ReaderWriterLockSlim
- 避免在
lock 區塊內執行耗時操作
- 考慮使用
CancellationToken 實作優雅取消
