util.c

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#include "util.h"

// channel functions
int is_current(int index) {
    if(index == I1H_INDEX || index == I1L_INDEX || index == I2H_INDEX || index == I2L_INDEX) {
        return 1;
    } else {
        return 0;
    }
}

int is_low_current(int index) {
    if(index == I1L_INDEX || index == I2L_INDEX) {
        return 1;
    } else {
        return 0;
    }
}

int count_channels(int channels[NUM_CHANNELS]) {
    int i = 0;
    int c = 0;
    for(i=0; i<NUM_CHANNELS; i++) {
        if(channels[i] == CHANNEL_ENABLED) {
            c++;
        }
    }
    return c;
}


int read_status(struct rl_status* status) {
    
    // map shared memory
    int shm_id = shmget(SHMEM_STATUS_KEY, sizeof(struct rl_status), SHMEM_PERMISSIONS);
    if (shm_id == -1) {
        rl_log(ERROR, "In read_status: failed to get shared status memory id; %d message: %s", errno, strerror(errno));
        return FAILURE;
    }
    struct rl_status* shm_status = (struct rl_status*) shmat(shm_id, NULL, 0);
    
    if (shm_status == (void *) -1) {
        rl_log(ERROR, "In read_status: failed to map shared status memory; %d message: %s", errno, strerror(errno));
        return FAILURE;
    }
    
    // read status
    *status = *shm_status;
    
    // unmap shared memory
    shmdt(shm_status);
    
    return SUCCESS;
}

int write_status(struct rl_status* status) {
    
    // map shared memory
    int shm_id = shmget(SHMEM_STATUS_KEY, sizeof(struct rl_status), IPC_CREAT | SHMEM_PERMISSIONS);
    if (shm_id == -1) {
        rl_log(ERROR, "In write_status: failed to get shared status memory id; %d message: %s", errno, strerror(errno));
        return FAILURE;
    }

    struct rl_status* shm_status = (struct rl_status*) shmat(shm_id, NULL, 0);
    if (shm_status == (void *) -1) {
        rl_log(ERROR, "In write_status: failed to map shared status memory; %d message: %s", errno, strerror(errno));
        return FAILURE;
    }
    
    // write status
    *shm_status = *status;
    
    // unmap shared memory
    shmdt(shm_status);
    
    return SUCCESS;
}


int ceil_div(int n, int d) {
    if(n%d == d || n%d == 0) {
        return n/d;
    } else {
        return n/d + 1;
    }
}


// ------------------------------ SIGNAL HANDLER ------------------------------ //

void sig_handler(int signo) {

    // signal generated by stop function
    if (signo == SIGQUIT) {
        // stop sampling
        status.sampling = SAMPLING_OFF;
    }

    // Ctrl+C handling
    if (signo == SIGINT) {
        signal(signo, SIG_IGN);
        printf("Stopping RocketLogger ...\n");
        status.sampling = SAMPLING_OFF;
    }
}
// TODO: allow forced Ctrl+C


// ------------------------------ FILE READING/WRITING  ------------------------------ //

int read_file_value(char filename[]) {
    FILE* fp;
    unsigned int value = 0;
    fp = fopen(filename, "rt");
    if (fp == NULL) {
        rl_log(ERROR, "failed to open file");
        return FAILURE;
    }
    if(fscanf(fp, "%x", &value) <= 0) {
        rl_log(ERROR, "failed to read from file");
        return FAILURE;
    }
    fclose(fp);
    return value;
}