read.c

/*
 * Copyright (c) 2009 Mark Heily <[email protected]>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "common.h"

static int sockfd[2];

static void
kevent_socket_drain(void)
{
    char buf[1];

    /* Drain the read buffer, then make sure there are no more events. */
    puts("draining the read buffer");
    if (read(sockfd[0], &buf[0], 1) < 1)
        err(1, "read(2)");
}

static void
kevent_socket_fill(void)
{
  puts("filling the read buffer");
    if (write(sockfd[1], ".", 1) < 1)
        err(1, "write(2)");
}


static void
test_kevent_socket_add(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_ADD)";
    struct kevent kev;

    test_begin(test_id);
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    success();
}

static void
test_kevent_socket_get(void)
{
    const char *test_id = "kevent(EVFILT_READ) wait";
    struct kevent kev;

    test_begin(test_id);

    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    kevent_socket_fill();

    kev.data = 1;
    kevent_cmp(&kev, kevent_get(kqfd));

    kevent_socket_drain();
    test_no_kevents();

    kev.flags = EV_DELETE;
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    success();
}

static void
test_kevent_socket_clear(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_CLEAR)";
    struct kevent kev;

    test_begin(test_id);

    test_no_kevents();

    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD | EV_CLEAR, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    kevent_socket_fill();
    kevent_socket_fill();

    kev.data = 2;
    kevent_cmp(&kev, kevent_get(kqfd)); 

    /* We filled twice, but drain once. Edge-triggered would not generate
       additional events.
     */
    kevent_socket_drain();
    test_no_kevents();

    kevent_socket_drain();
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_DELETE, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    success();
}

static void
test_kevent_socket_disable_and_enable(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_DISABLE)";
    struct kevent kev;

    test_begin(test_id);

    /*
     * Write to the socket before adding the event. This way we can verify that
     * enabling a triggered kevent causes the event to be returned immediately.
     */
    kevent_socket_fill();

    /* Add a disabled event. */
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD | EV_DISABLE, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    test_no_kevents();

    /* Re-enable the knote, then see if an event is generated */
    kev.flags = EV_ENABLE;
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);
    kev.flags = EV_ADD;
    kev.data = 1;
    kevent_cmp(&kev, kevent_get(kqfd));

    kevent_socket_drain();

    kev.flags = EV_DELETE;
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    success();
}

static void
test_kevent_socket_del(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_DELETE)";
    struct kevent kev;

    test_begin(test_id);

    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_DELETE, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    kevent_socket_fill();
    test_no_kevents();
    kevent_socket_drain();

    success();
}

static void
test_kevent_socket_oneshot(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_ONESHOT)";
    struct kevent kev;

    test_begin(test_id);

    /* Re-add the watch and make sure no events are pending */
    puts("-- re-adding knote");
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD | EV_ONESHOT, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);
    test_no_kevents();

    puts("-- getting one event");
    kevent_socket_fill();
    kev.data = 1;
    kevent_cmp(&kev, kevent_get(kqfd));

    puts("-- checking knote disabled");
    test_no_kevents();

    /* Try to delete the knote, it should already be deleted */
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_DELETE, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) == 0)
        err(1, "%s", test_id);

    kevent_socket_drain();

    success();
}


#if HAVE_EV_DISPATCH
static void
test_kevent_socket_dispatch(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_DISPATCH)";

    test_begin(test_id);

    struct kevent kev;

    /* Re-add the watch and make sure no events are pending */
    puts("-- re-adding knote");
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD | EV_DISPATCH, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);
    test_no_kevents();

    /* The event will occur only once, even though EV_CLEAR is not
       specified. */
    kevent_socket_fill();
    kev.data = 1;
    kevent_cmp(&kev, kevent_get(kqfd));
    test_no_kevents();

    /* Since the knote is disabled, the EV_DELETE operation succeeds. */
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_DELETE, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    kevent_socket_drain();

    success();
}
#endif  /* HAVE_EV_DISPATCH */

#if BROKEN
static void
test_kevent_socket_lowat(void)
{
    const char *test_id = "kevent(EVFILT_READ, NOTE_LOWAT)";
    struct kevent kev;

    test_begin(test_id);

    /* Re-add the watch and make sure no events are pending */
    puts("-- re-adding knote, setting low watermark to 2 bytes");
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD | EV_ONESHOT, NOTE_LOWAT, 2, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);
    test_no_kevents();

    puts("-- checking that one byte does not trigger an event..");
    kevent_socket_fill();
    test_no_kevents();

    puts("-- checking that two bytes triggers an event..");
    kevent_socket_fill();
    if (kevent(kqfd, NULL, 0, &kev, 1, NULL) != 1)
        err(1, "%s", test_id);
    KEV_CMP(kev, sockfd[0], EVFILT_READ, 0);
    test_no_kevents();

    kevent_socket_drain();
    kevent_socket_drain();

    success();
}
#endif

static void
test_kevent_socket_eof(void)
{
    const char *test_id = "kevent(EVFILT_READ, EV_EOF)";
    struct kevent kev;

    test_begin(test_id);

    /* Re-add the watch and make sure no events are pending */
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_ADD, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);
    test_no_kevents();

    if (close(sockfd[1]) < 0)
        err(1, "close(2)");

    kev.flags |= EV_EOF;
    kevent_cmp(&kev, kevent_get(kqfd));

    /* Delete the watch */
    EV_SET(&kev, sockfd[0], EVFILT_READ, EV_DELETE, 0, 0, &sockfd[0]);
    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0)
        err(1, "%s", test_id);

    success();
}

void
test_evfilt_read(void)
{
    /* Create a connected pair of full-duplex sockets for testing socket events */
    if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockfd) < 0) 
        abort();

    kqfd = kqueue();
    test_kevent_socket_add();
    test_kevent_socket_del();
    test_kevent_socket_get();
    test_kevent_socket_disable_and_enable();
    test_kevent_socket_oneshot();
    test_kevent_socket_clear();
#if HAVE_EV_DISPATCH
    test_kevent_socket_dispatch();
#endif
    test_kevent_socket_eof();
    close(kqfd);
}