kupl_shm_attach

进程A
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include "kupl.h"
#define SHM_NAME "/pid_shm_example"
typedef struct {
    pid_t pid;
    int ready;
    void* addr;
} shared_data_t;
int main() {
    // 创建共享内存对象、填入数据
    int shm_fd = shm_open(SHM_NAME, O_CREAT | O_RDWR, 0666);
    ftruncate(shm_fd, sizeof(shared_data_t);
    shared_data_t *shared_data = mmap(NULL, sizeof(shared_data_t),
                                      PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);         
    // 写入PID到共享内存
    shared_data->pid = getpid();
    printf("Process A: PID %d\n", shared_data->pid);
    shared_data->ready = 1;
    shared_data->addr = kupl_malloc(KUPL_MEM_DEFAULT, sizeof(shared_data_t));
    memset(shared_data->addr, 0, sizeof(shared_data_t));
    data_addr->pid = getpid();
    // 保持运行，等待进程B读取
    printf("Press Enter to exit...\n");
    getchar();
    // 清理
    kupl_free(KUPL_MEM_DEFAULT, shared_data->addr);
    munmap(shared_data, sizeof(shared_data_t));
    shm_unlink(SHM_NAME);
    return 0;
}

进程B
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include "kupl.h"
#define SHM_NAME "/pid_shm_example"
typedef struct {
    pid_t pid;
    int ready;
    void* addr;
} shared_data_t;
int main() {
    // 打开共享内存对象
    int shm_fd = shm_open(SHM_NAME, O_RDONLY, 0666);
    shared_data_t *shared_data = mmap(NULL, sizeof(shared_data_t),
                                     PROT_READ, MAP_SHARED, shm_fd, 0);
    shared_data_t *attach_data = (shared_data_t*)calloc(1, sizeof(shared_data_t));
    // 等待数据就绪
    while (shared_data->ready == 0) {
        usleep(100000); // 等待100ms
    }
    // 读取信息
    kupl_shm_addr_t kupl_shm_addr_info;
    kupl_shm_addr_info.src_addr = shared_data->addr;
    kupl_shm_addr_info.src_pid  = shared_data->pid;
    kupl_shm_addr_info.dst_pid  = getpid();
    // 执行映射
    attach_data->addr = kupl_shm_attach(kupl_shm_addr_info, sizeof(shared_data_t));
    if (attach_data->addr == NULL) {
        printf("attach wrong!\n");
    } else {
        printf("attach OK!");
    }
    // 等待数据就绪
    shared_data_t* data_addr = (shared_data_t*)attach_data->addr;
    while (data_addr->ready != 3) {
        usleep(100000); // 等待100ms
    }
    printf("Process B: Read PID %d from shared memory\n", data_addr->pid);
    // 清理
    munmap(shared_data, sizeof(shared_data_t));
    kupl_shm_detach(attach_data->addr);
    free(attach_data);
    close(shm_fd);
    return 0;
}