#include <stdio.h>
#include <sys/signalfd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <semaphore.h>
#include <dlfcn.h>

typedef struct {
    sem_t request_ready;
    sem_t response_ready;
    char func_name[20];
    double value;
    double result;
} shared_data_t;

int main(int argc, char** argv) {
    const char shm_name[] = "gachimuchi1488";
    int shm_id = shm_open(shm_name, O_RDWR | O_CREAT, 0666);

    size_t page_size = sysconf(_SC_PAGESIZE);
    size_t map_size = sizeof(shared_data_t);
    if (map_size % page_size > 0) {
        map_size = (map_size / page_size + 1) * page_size;
    }

    ftruncate(shm_id, map_size);
    shared_data_t* shared_data = mmap(NULL, map_size,
                                      PROT_READ | PROT_WRITE,
                                      MAP_SHARED, shm_id, 0);

    sem_init(&shared_data->request_ready, 1, 0);
    sem_init(&shared_data->response_ready, 1, 0);

    printf("%s", shm_name);
    fflush(stdout);

    void* shared_lib = dlopen(argv[1], RTLD_LAZY);

    while (1) {
        sem_wait(&shared_data->request_ready);
        if (strlen(shared_data->func_name) == 0) break;
        double (*func)(double) = dlsym(shared_lib, shared_data->func_name);
        shared_data->result = func(shared_data->value);
        sem_post(&shared_data->response_ready);
    }

    sem_destroy(&shared_data->request_ready);
    sem_destroy(&shared_data->response_ready);
    munmap(shared_data, map_size);
    shm_unlink(shm_name);
}