Linux 下监控程序 -- 共享内存通讯，消息订阅发布

实习的时候写的小练习程序：

VMSTAT.h

此代码用以从服务器获取运行状态信息

class VMSTAT{public:        double stat[20];        /*        *       Proc        *        * 0:r: The number of processes waiting for run time.        * 1:b: The number of processes in uninterruptible sleep.        *        *       Memory        *        * 2:swpd: the amount of virtual memory used.        * 3:free: the amount of idle memory.        * 4:buff: the amount of memory used as buffers.        * 5:cache: the amount of memory used as cache.        *        *       Swap        *        * 6:si: Amount of memory swapped in from disk (/s).        * 7:Amount of memory swapped to disk (/s).        *        *       IO        *        * 8:bi: Blocks received from a block device (blocks/s).        * 9:bo: Blocks sent to a block device (blocks/s).        *        *       System        *        * 10:in: The number of interrupts per second, including the clock.        * 11:cs: The number of context switches per second.        *        *       CPU        *        * 12:us: Time spent running non-kernel code. (user time, including nice time)        * 13:sy: Time spent running kernel code. (system time)        * 14:id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time.        * 15:wa: Time spent waiting for IO. Prior to Linux 2.5.41, included in idle.        * 16:st: Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown.        *        *       Add        *        * 17:Total Memory        * 18:Used Memory        * 19:CPU Usage        */        void update()        {                //init array                FILE* file = popen("vmstat","r");                char buf[300];                fgets (buf , 300 , file);                fgets (buf , 300 , file);                fgets (buf , 300 , file);                int index=0;                for(int i = 0;i<300;i++)                {                        while(buf[i]<'0'||buf[i]>'9') i++;                        int tmp = 0;                        while(buf[i]>='0'&&buf[i]<='9')                        {                                tmp = tmp*10 + (buf[i]-'0');                                i++;                        }                        stat[index++] = tmp*1.0;                        if(index == 17) break;                }                pclose(file);                //total memory                file = popen("cat /proc/meminfo","r");                double total=0;                fgets (buf , 300 , file);                char str[7];                for(int i=17;i<24;i++)                        str[i-17]=buf[i];                for(int i=0;i<7;i++)                {                        total =total*10+(str[i]==' '?0:(str[i]-'0'));                }                //calculate all                stat[17]=total;                stat[18]=total-stat[3];                stat[19]=100-stat[14];                pclose(file);        }};

pshm.h

定义共享内存数据结构的结构体

定义主题ID

typedef struct tagMyStat{        int attche_count;        int total;        int avaliable;        int used;        int cpu_useage;} MyStat;#define CENTOS_PER   (4499)  //主题CENTOS_PER 由服务器发布 客户端进行订阅 服务器可发布多个主题，而客户端可以选择其中若干个感兴趣的进行订阅

shmClient.cpp

#include <stdio.h>#include <time.h>#include <stdlib.h>#include <unistd.h>#include <sys/shm.h>#include  "VMSTAT.h"#include "pshm.h"int main(){        void *shm = NULL;        MyStat *shared = NULL;        int shmid = shmget((key_t)CENTOS_PER,sizeof(MyStat),IPC_CREAT);        if(shmid == -1)        {            printf("%s\n","shmget failed!");            return 0;        }        shm = shmat(shmid, (void*)0, 0);        if(shm == (void*)-1)        {            printf("%s\n","shmat failed!");        }        printf("Memory attached at %lx\n", (long)shm);        shared = (MyStat*)shm;        shared->attche_count ++;        time_t rawtime;        struct tm * t;        while(1)        {            time ( &rawtime );            t = localtime ( &rawtime );            printf("Client@%d:%d:%d :Total: %d MB  Aviliable: %d MB  Used: %d MB  CPU: %d %\n",t->tm_hour,t->tm_min,t->tm_sec,shared->total,shared->avaliable,shared->used,shared->cpu_useage);            sleep(1);        }        shared->attche_count --;        if(shmdt(shm) == -1)        {            printf("%s\n","shmdt failed!");        }        if(shmctl(shmid, IPC_RMID, 0) == -1)        {            printf("%s\n","shmctl(IPC_RMID) failed!");        }        sleep(2);        return 0;}

shmServer.cpp

#include <stdio.h>#include <time.h>#include <string.h>#include <stdlib.h>#include <unistd.h>#include <sys/shm.h>#include "VMSTAT.h"#include "pshm.h"int main(){        void *shm = NULL;        MyStat *shared = NULL;        int shmid = shmget((key_t)CENTOS_PER,sizeof(MyStat),0666|IPC_CREAT);        if(shmid == -1)        {            printf("%s\n","shmget failed!");            return 0;        }        shm = shmat(shmid, (void*)0, 0);        if(shm == (void*)-1)        {            printf("%s\n","shmat failed!");        }        printf("Memory attached at %lx\n", (long)shm);        shared = (MyStat*)shm;        memset(shared, 0, sizeof(MyStat));        shared->attche_count=0;        VMSTAT s;                time_t rawtime;        struct tm * t;                while(1)        {            s.update();            shared->total = int(s.stat[17]/1000);            shared->avaliable = int(s.stat[3]/1000);            shared->used = int(s.stat[18]/1000);            shared->cpu_useage = int(s.stat[19]);                     time ( &rawtime );            t = localtime ( &rawtime );            printf("Server@%2d:%2d:%2d (%d):Total: %d MB  Aviliable: %d MB  Used: %d MB  CPU: %d %\n",t->tm_hour,t->tm_min,t->tm_sec,shared->attche_count,shared->total,shared->avaliable,shared->used,shared->cpu_useage);            sleep(1);        }        if(shmdt(shm) == -1)        {            printf("%s\n","shmdt failed!");        }        if(shmctl(shmid, IPC_RMID, 0) == -1)        {            printf("%s\n","shmctl(IPC_RMID) failed!");        }        sleep(2);        return 0;}

服务器运行截图：

客户端运行截图：