基础共享内存通信示例

以下示例展示生产者-消费者模型，使用共享内存传递数据：

生产者程序（producer.c）

#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <string.h>

#define SHM_KEY 0x1234
#define SHM_SIZE 1024

int main() {
    int shmid = shmget(SHM_KEY, SHM_SIZE, IPC_CREAT | 0666);
    if (shmid == -1) {
        perror("shmget");
        return 1;
    }

    char *shm_ptr = (char*)shmat(shmid, NULL, 0);
    if (shm_ptr == (void*)-1) {
        perror("shmat");
        return 1;
    }

    strcpy(shm_ptr, "Hello from producer!");
    printf("Producer wrote: %s\n", shm_ptr);

    shmdt(shm_ptr);
    return 0;
}

消费者程序（consumer.c）

#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>

#define SHM_KEY 0x1234
#define SHM_SIZE 1024

int main() {
    int shmid = shmget(SHM_KEY, SHM_SIZE, 0666);
    if (shmid == -1) {
        perror("shmget");
        return 1;
    }

    char *shm_ptr = (char*)shmat(shmid, NULL, 0);
    if (shm_ptr == (void*)-1) {
        perror("shmat");
        return 1;
    }

    printf("Consumer read: %s\n", shm_ptr);

    shmdt(shm_ptr);
    shmctl(shmid, IPC_RMID, NULL); // 删除共享内存
    return 0;
}

编译与运行

# 编译
gcc producer.c -o producer
gcc consumer.c -o consumer

# 运行生产者
./producer
# 输出: Producer wrote: Hello from producer!

# 运行消费者
./consumer
# 输出: Consumer read: Hello from producer!

（通过 ipcs -m 查看共享内存）