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#define _GNU_SOURCE

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#include <signal.h>

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#include <string.h>

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#include <stdlib.h>

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#include <assert.h>

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#include "signals.h"

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#include "log.h"

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struct signals {

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    struct event_base *ev_base;

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    struct signal {

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        struct event *ev;

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    } sig_list[MAX_SIGNALS];

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    int sig_count;

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};

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void signals_loopexit (int signal, short event, void *arg) {

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    struct signals *signals = arg;

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    (void) event;

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    INFO("[signal] caught %s: exiting the event loop", strsignal(signal));

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    if (event_base_loopexit(signals->ev_base, NULL))

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        FATAL("event_base_loopexit");

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}

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void signals_ignore (int signal, short event, void *arg) {

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    struct signals *signals = arg;

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    (void) signal;

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    (void) event;

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    (void) arg;

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    (void) signals;

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    /* ignore */

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}

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struct signals *signals_alloc (struct event_base *ev_base) {

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    struct signals *signals = NULL;

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    if ((signals = calloc(1, sizeof(*signals))) == NULL)

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        ERROR("calloc");

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    // simple attributes

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    signals->ev_base = ev_base;

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    // done

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    return signals;

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error:

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    return NULL;

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}

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int signals_add (struct signals *signals, int sigval, void (*sig_handler)(evutil_socket_t, short, void *)) {

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    struct signal *sig_info;

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    // find our sig_info

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    assert(signals->sig_count < MAX_SIGNALS);

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    sig_info = &signals->sig_list[signals->sig_count++];

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    // set up the libevent signal events

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    if ((sig_info->ev = evsignal_new(signals->ev_base, sigval, sig_handler, signals)) == NULL)

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        PERROR("signal_new");

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    if (evsignal_add(sig_info->ev, NULL))

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        PERROR("signal_add");

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    // success

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    return 0;

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error:

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    return -1;

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}

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struct signals *signals_default (struct event_base *ev_base) {

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    struct signals *signals = NULL;

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    // alloc signals

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    if ((signals = signals_alloc(ev_base)) == NULL)

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        return NULL;

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    // add the set of default signals

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    if (    signals_add(signals,    SIGPIPE,    &signals_ignore)

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        ||  signals_add(signals,    SIGINT,     &signals_loopexit)

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    ) ERROR("signals_add");

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    // success

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    return signals;

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error:

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    if (signals)

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        signals_free(signals);

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    return NULL;

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}   

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void signals_free (struct signals *signals) {

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    int i;

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    // free all events

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    for (i = 0; i < signals->sig_count; i++) {

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        if (evsignal_del(signals->sig_list[i].ev))

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            PWARNING("signal_del");

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    }

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    // free the info itself

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    free(signals);

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}

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