};intmain(){// create shared memoryintshmid =shmget((key_t)1234,sizeof(shared_use_st),0666|IPC_CREAT);if(-1== shmid){fprintf(stderr,"shmget failed\n");exit(EXIT_FAILURE); }// attach shared memory to current processvoid* shm =shmat(shmid, (void*)0,0);if(shm == (void*)-1)...
/* create the shared memory object */ shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666); /* configure the size of the shared memory object */ ftruncate(shm_fd, SIZE); /* memory map the shared memory object */ ptr = mmap(0, SIZE, PROT_WRITE, MAP_SHARED, shm_fd, 0); /* ...
1. Create shared memory int shmget(key_t key, int size, int shmflg); if ((shm_id = shmget (mykey, sizeof (struct sharedbuf), 0600 | IFLAGS)) < 0) perror ("shmget"); 2. Attach shared memory char *buf = shmat (shm_id, 0, 0); 3. Read / Write shared memory sharedbuf->s...
int get_or_create_shared_memory(key_t key, int size, int flag){int shmid = shmget(key, size, flag);//成功返回共享内存标识符,失败返回-1if(shmid == -1){cout << "共享内存创建失败,原因是:" << strerror(errno) << endl;exit(2);}return shmid;}int create_shared_memory(key_t key, ...
21 printf("Create shared memory: %d.\n",shmid); 22 23 // ipcs 命令往标准输出写入一些关于活动进程间通信设施的信息 24 // -m 表示共享内存 25 printf("Created shared memory status:\n"); 26 system("ipcs -m"); 27 28 if((pid=fork())<0) { 29 perror("fork"); 30 exit(...
编译上述3个程序,首先运行create_shm程序创建一个共享内存: $ ./create_shm create a shared memory segment successfully: 3080264 --- Shared Memory Segments --- key shmid owner perms bytes nattch status 0x00000000 2260992 deeplearni 600 524288 2 dest 0x00000000 2490369...
// create a Posix shared memory int flags = O_RDWR | O_CREAT; fd = shm_open(shmfile, flags, FILE_MODE); if (fd < 0) { printf("shm_open failed, errormsg=%s errno=%d", strerror(errno), errno); return 0; } ftruncate(fd, size); ...
printf("failed to create share memory\n"); return-1; } addr = shmat(shmid,NULL,0); if(addr <=0) { printf("failed to map share memory\n"); return-1; } sprintf(addr,"%s","Hello World\n"); return0; } 进程B#include<stdio.h> ...
{cout<<"共享内存创建失败,原因是:"<<strerror(errno)<<endl;exit(2);}returnshmid;}intcreate_shared_memory(key_t key,int size){returnget_or_create_shared_memory(key,size,IPC_CREAT|IPC_EXCL|0666);}intget_shared_memory(key_t key,int size){returnget_or_create_shared_memory(key,size,IPC_...
共享内存(Shared Memory)是一种进程间通信(IPC,Inter-Process Communication)的方式,允许多个进程通过访问同一块内存区域来实现数据共享和快速通信。它是一种效率极高的通信机制,因为数据不需要在进程间进行复制,只需在同一块内存中直接读写即可。 1.2 共享内存的特点 ...