SDL 多线程创建同步

Posted 2022-08-29 qianbo_insist

目的

线程创建后让线程等待外部信号再继续运行，外部判断线程1 到达一个状态，再通知线程2 执行，代码如下所示：

#include <SDL2/SDL.h>

#include <stdio.h>
#include <Windows.h>

SDL_bool condition = SDL_FALSE;
SDL_mutex *lock;
SDL_cond *cond;


#pragma comment(lib,"../lib/sdl2.lib")
#pragma comment(lib,"../lib/sdl2main.lib")
int test = 10;
int threadA(void *arg) 
	SDL_LockMutex(lock);
	printf("in thread A\\n");
	test = 12;
	printf("test is %d\\n",test);
	SDL_UnlockMutex(lock);
	return 0;

int threadB(void *arg) 
	SDL_LockMutex(lock);
	printf("in thread B\\n");
	test = 13;
	printf("test is %d\\n", test);
	SDL_CondWait(cond, lock);
	test = 14;
	printf("test is %d\\n", test);
	SDL_UnlockMutex(lock);
	return 0;


int main(int argv, char* argc[])

	lock = SDL_CreateMutex();
	cond = SDL_CreateCond();
	SDL_Thread * t1 = SDL_CreateThread(threadA, "threada", NULL);
	SDL_Thread * t2 = SDL_CreateThread(threadB, "threadb", NULL);
	
	
	SDL_LockMutex(lock);
	printf("send signal====================>\\n");
	//condition = SDL_TRUE;
	SDL_CondSignal(cond);
	SDL_UnlockMutex(lock);
	SDL_DestroyCond(cond);
	SDL_DestroyMutex(lock);
	SDL_Quit();
	getchar();
	return 0;