text: /*-
   *   BSD LICENSE
   *
   *   Copyright(c) 2015-2016 Intel Corporation. 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 <inttypes.h>
  
  #include <rte_common.h>
  #include <rte_cycles.h>
  #include <rte_lcore.h>
  #include <rte_log.h>
  #include <rte_keepalive.h>
  #include <rte_malloc.h>
  
  struct rte_keepalive {
  	/** Core Liveness. */
  	enum rte_keepalive_state __rte_cache_aligned state_flags[
  		RTE_KEEPALIVE_MAXCORES];
  
  	/** Last-seen-alive timestamps */
  	uint64_t last_alive[RTE_KEEPALIVE_MAXCORES];
  
  	/**
  	 * Cores to check.
  	 * Indexed by core id, non-zero if the core should be checked.
  	 */
  	uint8_t active_cores[RTE_KEEPALIVE_MAXCORES];
  
  	/** Dead core handler. */
  	rte_keepalive_failure_callback_t callback;
  
  	/**
  	 * Dead core handler app data.
  	 * Pointer is passed to dead core handler.
  	 */
  	void *callback_data;
  	uint64_t tsc_initial;
  	uint64_t tsc_mhz;
  
  	/** Core state relay handler. */
  	rte_keepalive_relay_callback_t relay_callback;
  
  	/**
  	 * Core state relay handler app data.
  	 * Pointer is passed to live core handler.
  	 */
  	void *relay_callback_data;
  };
  
  static void
  print_trace(const char *msg, struct rte_keepalive *keepcfg, int idx_core)
  {
  	RTE_LOG(INFO, EAL, "%sLast seen %" PRId64 "ms ago.\n",
  		msg,
  		((rte_rdtsc() - keepcfg->last_alive[idx_core])*1000)
  		/ rte_get_tsc_hz()
  	      );
  }
  
  void
  rte_keepalive_dispatch_pings(__rte_unused void *ptr_timer,
  	void *ptr_data)
  {
  	struct rte_keepalive *keepcfg = ptr_data;
  	int idx_core;
  
  	for (idx_core = 0; idx_core < RTE_KEEPALIVE_MAXCORES; idx_core++) {
  		if (keepcfg->active_cores[idx_core] == 0)
  			continue;
  
  		switch (keepcfg->state_flags[idx_core]) {
  		case RTE_KA_STATE_UNUSED:
  			break;
  		case RTE_KA_STATE_ALIVE: /* Alive */
  			keepcfg->state_flags[idx_core] = RTE_KA_STATE_MISSING;
  			keepcfg->last_alive[idx_core] = rte_rdtsc();
  			break;
  		case RTE_KA_STATE_MISSING: /* MIA */
  			print_trace("Core MIA. ", keepcfg, idx_core);
  			keepcfg->state_flags[idx_core] = RTE_KA_STATE_DEAD;
  			break;
  		case RTE_KA_STATE_DEAD: /* Dead */
  			keepcfg->state_flags[idx_core] = RTE_KA_STATE_GONE;
  			print_trace("Core died. ", keepcfg, idx_core);
  			if (keepcfg->callback)
  				keepcfg->callback(
  					keepcfg->callback_data,
  					idx_core
  					);
  			break;
  		case RTE_KA_STATE_GONE: /* Buried */
  			break;
  		case RTE_KA_STATE_DOZING: /* Core going idle */
  			keepcfg->state_flags[idx_core] = RTE_KA_STATE_SLEEP;
  			keepcfg->last_alive[idx_core] = rte_rdtsc();
  			break;
  		case RTE_KA_STATE_SLEEP: /* Idled core */
  			break;
  		}
  		if (keepcfg->relay_callback)
  			keepcfg->relay_callback(
  				keepcfg->relay_callback_data,
  				idx_core,
  				keepcfg->state_flags[idx_core],
  				keepcfg->last_alive[idx_core]
  				);
  	}
  }
  
  struct rte_keepalive *
  rte_keepalive_create(rte_keepalive_failure_callback_t callback,
  	void *data)
  {
  	struct rte_keepalive *keepcfg;
  
  	keepcfg = rte_zmalloc("RTE_EAL_KEEPALIVE",
  		sizeof(struct rte_keepalive),
  		RTE_CACHE_LINE_SIZE);
  	if (keepcfg != NULL) {
  		keepcfg->callback = callback;
  		keepcfg->callback_data = data;
  		keepcfg->tsc_initial = rte_rdtsc();
  		keepcfg->tsc_mhz = rte_get_tsc_hz() / 1000;
  	}
  	return keepcfg;
  }
  
  void rte_keepalive_register_relay_callback(struct rte_keepalive *keepcfg,
  	rte_keepalive_relay_callback_t callback,
  	void *data)
  {
  	keepcfg->relay_callback = callback;
  	keepcfg->relay_callback_data = data;
  }
  
  void
  rte_keepalive_register_core(struct rte_keepalive *keepcfg, const int id_core)
  {
  	if (id_core < RTE_KEEPALIVE_MAXCORES) {
  		keepcfg->active_cores[id_core] = RTE_KA_STATE_ALIVE;
  		keepcfg->last_alive[id_core] = rte_rdtsc();
  	}
  }
  
  void
  rte_keepalive_mark_alive(struct rte_keepalive *keepcfg)
  {
  	keepcfg->state_flags[rte_lcore_id()] = RTE_KA_STATE_ALIVE;
  }
  
  void
  rte_keepalive_mark_sleep(struct rte_keepalive *keepcfg)
  {
  	keepcfg->state_flags[rte_lcore_id()] = RTE_KA_STATE_DOZING;
  }
  