POSIX线程同步方法详解
1. 线程管理与取消
在进程运行时,往往会有一个专门用于管理其他线程的线程。当一个线程被取消时,虽然其任务停止,但线程ID仍处于活跃状态,这是为了防止其他线程调用pthread_join时出现问题。不过,线程终止时,创建该线程所使用的资源会被释放。
2. POSIX线程同步方法 - 互斥锁(Mutex)
2.1 酒店房间预订示例
以酒店房间预订应用为例,最初的代码在单线程运行时能正常工作,但多线程运行时会出现问题。以下是最初的代码示例:
unit unitMutexExampleForm; { This is a demo for a hotel that books individual rooms. This demonstrates the wrong way to access variables that will be shared among different threads. Running this application is designed to give incorrect results } interface uses SysUtils, Types, Classes, Variants, QGraphics, QControls, QForms, QDialogs, Libc, QStdCtrls, QComCtrls; type TfrmMutexDemo = class(TForm) btnSReserveRooms: TButton; mmInfo: TMemo; Label1: TLa