DPDK  20.11.3
examples/l2fwd-keepalive/shm.c
/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2016 Intel Corporation
*/
#include <time.h>
#include <rte_common.h>
#include <rte_log.h>
#include <rte_keepalive.h>
#include "shm.h"
struct rte_keepalive_shm *rte_keepalive_shm_create(void)
{
int fd;
int idx_core;
struct rte_keepalive_shm *ka_shm;
/* If any existing object is not unlinked, it makes it all too easy
* for clients to end up with stale shared memory blocks when
* restarted. Unlinking makes sure subsequent shm_open by clients
* will get the new block mapped below.
*/
if (shm_unlink(RTE_KEEPALIVE_SHM_NAME) == -1 && errno != ENOENT)
printf("Warning: Error unlinking stale %s (%s)\n",
RTE_KEEPALIVE_SHM_NAME, strerror(errno));
fd = shm_open(RTE_KEEPALIVE_SHM_NAME,
O_CREAT | O_TRUNC | O_RDWR, 0666);
if (fd < 0)
RTE_LOG(INFO, EAL,
"Failed to open %s as SHM (%s)\n",
RTE_KEEPALIVE_SHM_NAME,
strerror(errno));
else if (ftruncate(fd, sizeof(struct rte_keepalive_shm)) != 0)
RTE_LOG(INFO, EAL,
"Failed to resize SHM (%s)\n", strerror(errno));
else {
ka_shm = (struct rte_keepalive_shm *) mmap(
0, sizeof(struct rte_keepalive_shm),
PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
close(fd);
if (ka_shm == MAP_FAILED)
RTE_LOG(INFO, EAL,
"Failed to mmap SHM (%s)\n", strerror(errno));
else {
memset(ka_shm, 0, sizeof(struct rte_keepalive_shm));
/* Initialize the semaphores for IPC/SHM use */
if (sem_init(&ka_shm->core_died, 1, 0) != 0) {
RTE_LOG(INFO, EAL,
"Failed to setup SHM semaphore (%s)\n",
strerror(errno));
munmap(ka_shm,
sizeof(struct rte_keepalive_shm));
return NULL;
}
/* Set all cores to 'not present' */
for (idx_core = 0;
idx_core++) {
ka_shm->core_state[idx_core] =
RTE_KA_STATE_UNUSED;
ka_shm->core_last_seen_times[idx_core] = 0;
}
return ka_shm;
}
}
return NULL;
}
void rte_keepalive_relayed_state(struct rte_keepalive_shm *shm,
const int id_core, const enum rte_keepalive_state core_state,
__rte_unused uint64_t last_alive)
{
int count;
shm->core_state[id_core] = core_state;
shm->core_last_seen_times[id_core] = last_alive;
if (core_state == RTE_KEEPALIVE_SHM_DEAD) {
/* Since core has died, also signal ka_agent.
*
* Limit number of times semaphore can be incremented, in case
* ka_agent is not active.
*/
if (sem_getvalue(&shm->core_died, &count) == -1) {
RTE_LOG(INFO, EAL, "Semaphore check failed(%s)\n",
strerror(errno));
return;
}
if (count > 1)
return;
if (sem_post(&shm->core_died) != 0)
RTE_LOG(INFO, EAL,
"Failed to increment semaphore (%s)\n",
strerror(errno));
}
}
void rte_keepalive_shm_cleanup(struct rte_keepalive_shm *ka_shm)
{
if (shm_unlink(RTE_KEEPALIVE_SHM_NAME) == -1 && errno != ENOENT)
printf("Warning: Error unlinking %s (%s)\n",
RTE_KEEPALIVE_SHM_NAME, strerror(errno));
if (ka_shm && munmap(ka_shm, sizeof(struct rte_keepalive_shm)) != 0)
printf("Warning: munmap() failed\n");
}