信号的漏桶实现

1、一段时间内打印固定数据

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <stdbool.h>
#include <errno.h>
#include <fcntl.h>
#define SPEED    1024
#define BUFFSIZE  SPEED

volatile static bool loop = false;
#define ALARM   3
static void alrm_handler(int signo)
{

    alarm(3);
    loop = true;
}


int main( int argc, char** argv)
{


    if( argc < 2)
    {
        fprintf(stderr,"Usage:%s <src_file> \n",argv[0]);

        exit(0);
    }


    int sfd,dfd = 1;
    char buff[BUFFSIZE];
    if( (sfd = open(argv[1],O_RDONLY))<0)
    {
        perror("open()");
        exit(1);
    }
    signal(SIGALRM,alrm_handler);    
    alarm(3);
    while(1)
    {
      while(!loop)
          pause();
      loop = false;
      ssize_t read_size;
 errno =0;
      while((read_size =  read(sfd,buff,BUFFSIZE)) < 0)
      {
       
            if( errno == EINTR)
          {
              errno = 0;
                continue;
         }
      }
  
    
//      read_size =  read(sfd,buff,BUFFSIZE);
      
      if( read_size == 0)
          break;
      if( read_size < 0)
          break;
      ssize_t write_size = 0;
      errno = 0;
      while( read_size)
      {
          ssize_t ret = write(dfd,buff+write_size,read_size);
          if( ret < 0 && errno != EINTR)
          {
              break;
          }
          errno =0;
          read_size -= ret;
      }
    }



    close(sfd);
    exit(0);

}

2、 实现令牌桶

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <stdbool.h>
#include <errno.h>
#include <fcntl.h>
#define SPEED    1024
#define BUFFSIZE  SPEED
#define  BURST   100
volatile static bool loop = false;
#define ALARM   1
volatile static int token =0;
static void alrm_handler(int signo)
{

    alarm(ALARM);
 //   loop = true;
    token ++;
    if( token > BURST)
        token = BURST;
}


int main( int argc, char** argv)
{


    if( argc < 2)
    {
        fprintf(stderr,"Usage:%s <src_file> \n",argv[0]);

        exit(0);
    }


    int sfd,dfd = 1;
    char buff[BUFFSIZE];
    if( (sfd = open(argv[1],O_RDONLY))<0)
    {
        perror("open()");
        exit(1);
    }
    signal(SIGALRM,alrm_handler);    
    alarm(3);
    while(1)
    {
      while(token <=0)
          pause();
         token--;
      //loop = false;
      ssize_t read_size;
      errno =0;
      while((read_size =  read(sfd,buff,BUFFSIZE)) < 0)
      {
       
            if( errno == EINTR)
          {
              errno = 0;
                continue;
         }
      }
  
    
//      read_size =  read(sfd,buff,BUFFSIZE);
      
      if( read_size == 0)
          break;
      if( read_size < 0)
          break;
      ssize_t write_size = 0;
      errno = 0;
      while( read_size)
      {
          ssize_t ret = write(dfd,buff+write_size,read_size);
          if( ret < 0 && errno != EINTR)
          {
              break;
          }
          errno =0;
          read_size -= ret;
      }
    }



    close(sfd);
    exit(0);

}