SDL线程相关
- SDL线程创建：SDL_CreateThread
- SDL线程等待: SDL_WaitThread
- SDL互斥锁 :SDL_CreateMutex/SDL_DestoryMutex
- SDL锁定互斥: SDL_LockMutex/SDL_UnlockMutex
- SDL条件变量:SDL_CreateCond/SDL_DestoryCond
- SDL条件变量 等待通知: SDL_CondWait/SDL_CondSingal
#include <SDL.h>
#include <stdio.h>SDL_mutex *s_lock = NULL;
SDL_cond *s_cond = NULL;int thread_work(void *arg) {SDL_LockMutex(s_lock);printf(" <============thread_work sleep\n");sleep(10); // 用来测试获取锁printf(" <============thread_work wait\n");// 释放s_lock资源，并等待signal。之所以释放s_lock是让别的线程能够获取到s_lockSDL_CondWait(s_cond, s_lock); // 另一个线程(1)发送signal和(2)释放lock后，这个函数退出printf(" <===========thread_work receive signal, continue to do ~_~!!!\n");printf(" <===========thread_work end\n");SDL_UnlockMutex(s_lock);return 0;
}#undef main
int main() {// 锁s_lock = SDL_CreateMutex();// 条件变量s_cond = SDL_CreateCond();SDL_Thread *t = SDL_CreateThread(thread_work, "thread_work", NULL);if (!t) {printf(" %s", SDL_GetError);return -1;}for (int i = 0; i < 2; i++) {sleep(2);printf("main execute =====>\n");}printf("main SDL_LockMutex(s_lock) before ====================>\n");SDL_LockMutex(s_lock); // 获取锁，但是子线程还拿着锁printf("main ready send signal====================>\n");printf("main SDL_CondSignal(s_cond) before ====================>\n");SDL_CondSignal(s_cond); // 发送信号，唤醒等待的线程printf("main SDL_CondSignal(s_cond) after ====================>\n");sleep(10);SDL_UnlockMutex(s_lock); // 释放锁，让其他线程可以拿到锁printf("main SDL_UnlockMutex(s_lock) after ====================>\n");SDL_WaitThread(t, NULL);SDL_DestroyMutex(s_lock);SDL_DestroyCond(s_cond);return 0;
}
这里面的信号量什么的 和 规范的那一套逻辑设计的是一样的
之前学过线程信号量相关的知识 在这里也是更换了一下函数
代码的主要逻辑是
创建子线程 子线程先拿到锁 休眠10s后 释放锁并等待信号量
主线程拿到锁 发送信号量 唤醒子线程 休眠10s后 释放锁
子线程拿到锁 输出文本并释放锁
主线程等待子线程结束后 结束流程