examples/l2fwd-keepalive/ka-agent/main.c

/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2016 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <sys/queue.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <time.h>

#include <rte_keepalive.h>

#include <shm.h>

#define MAX_TIMEOUTS 4
#define SEM_TIMEOUT_SECS 2

static struct rte_keepalive_shm *ka_shm_create(void)
{
        int fd = shm_open(RTE_KEEPALIVE_SHM_NAME, O_RDWR, 0666);
        size_t size = sizeof(struct rte_keepalive_shm);
        struct rte_keepalive_shm *shm;

        if (fd < 0)
                printf("Failed to open %s as SHM:%s\n",
                        RTE_KEEPALIVE_SHM_NAME,
                strerror(errno));
        else {
                shm = (struct rte_keepalive_shm *) mmap(
                        0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
                close(fd);
                if (shm == MAP_FAILED)
                        printf("Failed to mmap SHM:%s\n", strerror(errno));
                else
                        return shm;
        }

        /* Reset to zero, as it was set to MAP_FAILED aka: (void *)-1 */
        shm = 0;
        return NULL;
}

int main(void)
{
        struct rte_keepalive_shm *shm = ka_shm_create();
        struct timespec timeout = { .tv_nsec = 0 };
        int idx_core;
        int cnt_cores;
        uint64_t last_seen_alive_time = 0;
        uint64_t most_recent_alive_time;
        int cnt_timeouts = 0;
        int sem_errno;

        if (shm == NULL) {
                printf("Unable to access shared core state\n");
                return 1;
        }
        while (1) {
                most_recent_alive_time = 0;
                for (idx_core = 0; idx_core < RTE_KEEPALIVE_MAXCORES;
                                idx_core++)
                        if (shm->core_last_seen_times[idx_core] >
                                        most_recent_alive_time)
                                most_recent_alive_time =
                                        shm->core_last_seen_times[idx_core];

                timeout.tv_sec = time(NULL) + SEM_TIMEOUT_SECS;
                if (sem_timedwait(&shm->core_died, &timeout) == -1) {
                        /* Assume no core death signals and no change in any
                         * last-seen times is the keepalive monitor itself
                         * failing.
                         */
                        sem_errno = errno;
                        last_seen_alive_time = most_recent_alive_time;
                        if (sem_errno == ETIMEDOUT) {
                                if (last_seen_alive_time ==
                                                most_recent_alive_time &&
                                                cnt_timeouts++ >
                                                MAX_TIMEOUTS) {
                                        printf("No updates. Exiting..\n");
                                        break;
                                        }
                        } else
                                printf("sem_timedwait() error (%s)\n",
                                        strerror(sem_errno));
                        continue;
                }
                cnt_timeouts = 0;

                cnt_cores = 0;
                for (idx_core = 0; idx_core < RTE_KEEPALIVE_MAXCORES;
                                idx_core++)
                        if (shm->core_state[idx_core] == RTE_KA_STATE_DEAD)
                                cnt_cores++;
                if (cnt_cores == 0) {
                        /* Can happen if core was restarted since Semaphore
                         * was sent, due to agent being offline.
                         */
                        printf("Warning: Empty dead core report\n");
                        continue;
                }

                printf("%i dead cores: ", cnt_cores);
                for (idx_core = 0;
                                idx_core < RTE_KEEPALIVE_MAXCORES;
                                idx_core++)
                        if (shm->core_state[idx_core] == RTE_KA_STATE_DEAD)
                                printf("%d, ", idx_core);
                printf("\b\b\n");
        }
        if (munmap(shm, sizeof(struct rte_keepalive_shm)) != 0)
                printf("Warning: munmap() failed\n");
        return 0;
}