setjmp和longjmp函数使用

这里用最简单直接的描述：这两组函数是用于实现类似vscode全局的标签跳转功能，setjmp负责埋下标签，longjmp负责标签跳转。

#include <stdio.h>
#include <stdlib.h>
#include <setjmp.h>jmp_buf envbuf1;
jmp_buf envbuf2;void func_label1()
{int ret = setjmp(envbuf1);printf("func label1 ret:%d.\n",ret);
}void func_label2()
{int ret = setjmp(envbuf2);printf("func label2 ret:%d.\n",ret);
}void test1()
{printf("test1 called.\n");longjmp(envbuf1,100);printf("test1 never run here.\n");
}void test2()
{printf("test2 called.\n");longjmp(envbuf1,200);printf("test2 never run here.\n");
}void test3()
{printf("test3 called.\n");longjmp(envbuf1,300);printf("test3 never run here.\n");
}void test4()
{printf("test4 called.\n");longjmp(envbuf2,400);printf("test4 never run here.\n");
}void test5()
{printf("test5 called.\n");longjmp(envbuf2,500);printf("test5 never run here.\n");
}void main()
{printf("==========Start process======\n");func_label1();func_label2();test1();//label1test2();test3();test4();//label2test5();printf("==========End process======\n");
}

运行效果：

从这个运行结果可以清楚的看到两个标签的跳转效果！

#include <stdio.h>
#include <unistd.h>
#include <setjmp.h>
#include <stdlib.h>typedef struct
{void *private_data;void (*start)(void *);jmp_buf context; // 上下文切换} context;static context *task_list;
static int run_index = 0;
static int index_max = 0;
static int count = 0;static void task0(void *arg)
{printf("task0,arg=%d\n", arg);
}static void task1(void *arg)
{printf("task1,arg=%d\n", arg);
}static void task2(void *arg)
{printf("task2,arg=%d\n", arg);
}static void run(context *ct)
{printf("run_index=%d, count=%d\n", run_index, ++count);ct->start(ct->private_data);   run_index = count % index_max;    sleep(1);longjmp(task_list[run_index].context, 1);//switch to next task
}void task_init(int size)
{task_list = (context *)malloc(size * sizeof(context));
}void create_task(void (*start)(void *), void *arg)
{task_list[index_max].start = start;task_list[index_max].private_data = arg;if (setjmp(task_list[index_max].context)){run(&task_list[run_index]);}index_max++; // 记录创建的任务数量
}void task_start()
{longjmp(task_list[0].context, 1); // 开始第一个任务
}int main()
{task_init(3); // thread max=3create_task(task0, (void *)100);create_task(task1, (void *)101);create_task(task2, (void *)102);task_start();return 0;
}