linux进程共享内存【POSIX】

主端

#include <iostream>
#include <cstring>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

#define SHM_NAME "/my_shm"
#define SHM_SIZE 1024

int main() {
    // 创建共享内存对象
    int shm_fd = shm_open(SHM_NAME, O_CREAT | O_RDWR, 0666);
    if (shm_fd == -1) {
        perror("shm_open");
        return 1;
    }

    // 调整共享内存对象的大小
    if (ftruncate(shm_fd, SHM_SIZE) == -1) {
        perror("ftruncate");
        close(shm_fd);
        return 1;
    }

    // 将共享内存对象映射到进程的地址空间
    void* ptr = mmap(0, SHM_SIZE, PROT_WRITE, MAP_SHARED, shm_fd, 0);
    if (ptr == MAP_FAILED) {
        perror("mmap");
        close(shm_fd);
        return 1;
    }

    // 写入数据到共享内存
    const char* message = "Hello, this is a shared memory example!";
    std::memcpy(ptr, message, strlen(message) + 1);

    // 等待一段时间，以便reader进程可以读取数据
    sleep(5);

    // 取消映射共享内存
    if (munmap(ptr, SHM_SIZE) == -1) {
        perror("munmap");
        close(shm_fd);
        return 1;
    }

    // 关闭共享内存对象
    close(shm_fd);

    // 删除共享内存对象
    if (shm_unlink(SHM_NAME) == -1) {
        perror("shm_unlink");
        return 1;
    }

    return 0;
}

副端测试

#include <iostream>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>

#define SHM_NAME "/my_shm"
#define SHM_SIZE 1024

int main() {
    // 打开共享内存对象
    int shm_fd = shm_open(SHM_NAME, O_RDONLY, 0666);
    if (shm_fd == -1) {
        perror("shm_open");
        return 1;
    }

    // 将共享内存对象映射到进程的地址空间
    const void* ptr = mmap(0, SHM_SIZE, PROT_READ, MAP_SHARED, shm_fd, 0);
    if (ptr == MAP_FAILED) {
        perror("mmap");
        close(shm_fd);
        return 1;
    }

    // 读取数据并打印
    const char* message = static_cast<const char*>(ptr);
    std::cout << "Received message: " << message << std::endl;

    // 取消映射共享内存
    if (munmap(const_cast<void*>(ptr), SHM_SIZE) == -1) {
        perror("munmap");
        close(shm_fd);
        return 1;
    }

    // 关闭共享内存对象
    close(shm_fd);

    return 0;
}

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*转载请注明出处：原文链接：https://cpp.vin/page/149.html