OS 6 client.cpp

#include <cerrno>
#include <cstdio>
#include <cstdlib>
#include <unistd.h>
#include <sys/iomsg.h>
#include <sys/neutrino.h>
#include "httpd_pid.h"

const char MSG1[ ] = "echo Timer 1 elapsed.";
const char MSG2[ ] = "echo Timer 2 elapsed.";

int connectionId;

void Handler(int signalId) {
    printf("SIGUSR%d\n", signalId - SIGUSR1 + 1);
    const char* msg;
    size_t size;
    if (signalId == SIGUSR1) {
        msg = MSG1;
        size = sizeof MSG1;
    } else {
        msg = MSG2;
        size = sizeof MSG2;
    }
    char unused;
    if (MsgSend(connectionId, msg, size, &unused, sizeof unused) == -1) {
        fputs("Cannot send a message\n", stderr);
        exit(1);
    }
}

void InitTimer(struct sigaction& act, timer_t& timerId, int signalId) {
    sigset_t st;
    sigemptyset(&st);
    sigaddset(&st, signalId);
    act.sa_flags = 0;
    act.sa_mask = 0x00;
    act.sa_handler = Handler;
    sigaction(signalId, &act, NULL);
    sigevent event;
    SIGEV_SIGNAL_INIT(&event, signalId);
    if (timer_create(CLOCK_REALTIME, &event, &timerId) == -1) {
        fprintf(stderr, "Cannot create a timer (errno %d)\n", errno);
        exit(1);
    }
}

int main() {
    FILE* f = fopen(HTTPD_PID, "r");
    if (!f) {
        fputs("Cannot open \"" HTTPD_PID "\"\n", stderr);
        return 1;
    }
    int nodeDescriptor, serverId, channelId;
    bool ok = fscanf(f, "%d/%d/%d", &nodeDescriptor, &serverId, &channelId) == 3;
    fclose(f);
    if (!ok) {
        fputs("Invalid file format\n", stderr);
        return 1;
    }
    connectionId = ConnectAttach(nodeDescriptor, serverId, channelId, 0, 0);
    if (connectionId == -1) {
        fputs("Server is not found\n", stderr);
        return 1;
    }

    struct sigaction act1, act2;
    timer_t timerId1, timerId2;
    itimerspec spec;
    InitTimer(act1, timerId1, SIGUSR1);
    InitTimer(act2, timerId2, SIGUSR2);

    spec.it_value.tv_sec  = spec.it_interval.tv_sec  = 3;
    spec.it_value.tv_nsec = spec.it_interval.tv_nsec = 0;
    timer_settime(timerId1, 0, &spec, NULL);

    spec.it_value.tv_sec  = spec.it_interval.tv_sec  = 4;
    spec.it_value.tv_nsec = spec.it_interval.tv_nsec = (int).44e9;
    timer_settime(timerId2, 0, &spec, NULL);

    while (true)
        sleep(~0U);
}