#define _GNU_SOURCE  

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/memfd.h>
#include <sys/syscall.h>
#include <sys/mman.h>
#include <fcntl.h>

#include "network.h"
#include "swap.h"



int make_swap(rbt_msg *swap)
{
   swap->state = NEWMSG;
   sem_post(&swap->status);
}

int create_swap(const char *name)
{
   int fd = memfd_create(name,0);

   //申请共享内存
   ftruncate(fd, sizeof(rbt_msg));
   //调整关闭策略
   int flags = fcntl(fd, F_GETFD);
   flags &= ~FD_CLOEXEC;
   fcntl(fd, F_SETFD, flags);
   //调整大小
   rbt_msg *init_msg = (rbt_msg*)mmap(NULL, sizeof(rbt_msg), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
   char buf[NET_MAX_MESSAGE_BUF] = {'\0'};
   //初始化
   memcpy(init_msg->raw_message,buf,NET_MAX_MESSAGE_BUF);
   memcpy(init_msg->nickname,buf,64);
   sem_init(&init_msg->status,1,1);
   init_msg->raw_message[0] = '\0';
   init_msg->state = MEM_FREE;
   init_msg->uid[0] = '\0';
   munmap((void*)init_msg,sizeof(rbt_msg)); 
   return fd;
}

int close_swap(int shmid,rbt_msg *swap)
{
   swap->state = QUITPLG;//置退出态
   sem_post(&swap->status);//发送信号量
   close(shmid);//关闭共享内存
}