用c语言简单模拟协程

看了云风的http://blog.codingnow.com/2012/07/c_coroutine.html，他实现了一个简单的协程调度。

我这里仅仅是用c语言模拟了协程，原理很简单。

主要是:

getcontext()

makecontext()

swapcontext()

这几个函数。具体api详解见http://pubs.opengroup.org/onlinepubs/009695399/functions/makecontext.html

#ifndef _CORO_H
#define _COEO_H
#include <ucontext.h>
typedef void (*coro_func)(void *);
typedef struct coro_context
{
        ucontext_t context;
        coro_func func;
        void *argv;
        char *sptr;
        size_t ssize;
}coro_context_t;
coro_context_t* coro_create(coro_func coro,void *arg,void *sptr,size_t ssize);
void coro_transfer (coro_context_t *prev, coro_context_t *next);
void coro_destroy (coro_context_t *ctx);
#endif

#include"coro.h"
#include <stdlib.h>
coro_context_t* coro_create(coro_func func,void *arg,void *sptr,size_t ssize)
{
    coro_context_t *ctx = (coro_context_t*)malloc(sizeof(coro_context_t));
    getcontext(&ctx->context);
    ctx->context.uc_link = 0;
    ctx->context.uc_stack.ss_sp = sptr;
    ctx->context.uc_stack.ss_size = ssize;
    ctx->context.uc_stack.ss_flags = 0;
    makecontext(&ctx->context, (void (*)(void)) func, 1, arg);
    return ctx;
}


void coro_transfer (coro_context_t *prev, coro_context_t *next)
{
    swapcontext(&prev->context, &next->context);
}

void coro_destroy (coro_context_t *ctx)
{
    free(ctx);
}

#include"coro.h"
#include<stdio.h>
coro_context_t *coro1;
coro_context_t *maincoro;
char stack1[1024*16];
char stack2[1024*16];
void test1(void *argv)
{
    printf("test\n");
}
int main(){
    coro1 = coro_create(test1,NULL,stack1,1024*8);
    maincoro = coro_create(NULL,NULL,stack2,1024*8);
    while(1){
        coro_transfer(maincoro,coro1);
        printf("main\n");
    }
    coro_destroy(coro1);
    coro_destroy(maincoro);
}