timer_hello.c

performance:

/*
 *   Copyright (c) 2016, Nokia Solutions and Networks
 *   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 the copyright holder 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,
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 *   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.
 */
 
/**
 * @file
 *
 * Event Machine Timer hello world example.
 *
 * Timer hello world example to show basic event timer usage. Creates a
 * single EO that starts a periodic and a random one-shot timeout.
 *
 * Exception/error management is simplified to focus on basic timer usage.
 */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
 
#include <event_machine.h>
#include <event_machine/platform/env/environment.h>
 
#include "cm_setup.h"
#include "cm_error_handler.h"
 
/* test app defines */
#define APP_MAX_TEXT_LEN        128     /* string length limit */
#define APP_TIMEOUT_MODULO_MS   30000   /* max random timeout */
#define APP_TIMEOUT_MIN_MS      100     /* minimum random timeout */
#define APP_PERIOD_MS           1000    /* heartbeat tick period */
 
#define APP_EO_NAME "Control EO"
 
/**
 * Example application message event
 */
typedef enum app_cmd_t {
        APP_CMD_TMO,            /* periodic timeout */
        APP_CMD_HELLO           /* random timeout */
} app_cmd_t;
 
typedef struct app_msg_t {
        app_cmd_t command;
        uint64_t count;
        char text[APP_MAX_TEXT_LEN];
        /* for managing periodic timeouts */
        em_tmo_t tmo;
} app_msg_t;
 
/**
 * EO context
 */
typedef struct app_eo_ctx_t {
        em_tmo_t periodic_tmo;
        em_tmo_t random_tmo;
        em_queue_t my_q;
        uint64_t hz;
} app_eo_ctx_t;
 
/**
 * Timer hello world shared memory data
 */
typedef struct timer_app_shm_t {
        /* Event pool used by this application */
        em_pool_t pool;
        /* EO context data */
        app_eo_ctx_t eo_context;
        em_queue_t eo_q;
        em_timer_t tmr;
        /* Pad size to a multiple of cache line size */
        void *end[0] ENV_CACHE_LINE_ALIGNED;
} timer_app_shm_t;
 
/* EM-core locals */
static ENV_LOCAL timer_app_shm_t *m_shm;
static ENV_LOCAL unsigned int m_randseed;
 
/* Local function prototypes */
static em_status_t app_eo_start(app_eo_ctx_t *eo_ctx, em_eo_t eo,
                                const em_eo_conf_t *conf);
static em_status_t app_eo_start_local(app_eo_ctx_t *eo_ctx, em_eo_t eo);
static em_status_t app_eo_stop(app_eo_ctx_t *eo_ctx, em_eo_t eo);
static void app_eo_receive(app_eo_ctx_t *eo_ctx, em_event_t event,
                           em_event_type_t type, em_queue_t queue,
                           void *q_ctx);
static void new_rand_timeout(app_eo_ctx_t *eo_ctx);
 
/**
 * Main function
 *
 * Call cm_setup() to perform test & EM setup common for all the
 * test applications.
 *
 * cm_setup() will call test_init() and test_start() and launch
 * the EM dispatch loop on every EM-core.
 */
int main(int argc, char *argv[])
{
        return cm_setup(argc, argv);
}
 
/**
 * Before EM - Init of the test application.
 *
 * The shared memory is needed if EM instance runs on multiple processes.
 * Doing it like this makes it possible to run the app both as threads (-t)
 * as well as processes (-p).
 *
 * @attention Run on all cores.
 *
 * @see cm_setup() for setup and dispatch.
 */
void test_init(const appl_conf_t *appl_conf)
{
        (void)appl_conf;
        int core = em_core_id();
 
        if (core == 0) {
                /* first core creates the ShMem */
                m_shm = env_shared_reserve("TimerAppShMem",
                                           sizeof(timer_app_shm_t));
                em_register_error_handler(test_error_handler);
        } else {
                m_shm = env_shared_lookup("TimerAppShMem");
        }
 
        if (m_shm == NULL) {
                test_error(EM_ERROR_SET_FATAL(0xDEAD), 0xBEEF,
                           "init failed on EM-core: %u",
                           em_core_id());
        } else if (core == 0) {
                /* initialize shared memory for EM app init */
                memset(m_shm, 0, sizeof(timer_app_shm_t));
        }
}
 
/**
 * Startup of the timer hello EM application.
 *
 * At this point EM is up, but no EOs exist. EM API can be used to create
 * queues, EOs etc.
 *
 * @attention Run only on EM core 0.
 *
 * @param appl_conf Application configuration
 *
 * @see cm_setup() for setup and dispatch.
 */
void test_start(const appl_conf_t *appl_conf)
{
        em_eo_t eo;
        em_timer_attr_t attr;
        em_queue_t queue;
        em_status_t stat;
        em_event_t event;
        app_msg_t *msg;
        app_eo_ctx_t *eo_ctx;
        uint64_t period;
 
        /*
         * Store the event pool to use, use the EM default pool if no other
         * pool is provided through the appl_conf.
         */
        if (appl_conf->num_pools >= 1)
                m_shm->pool = appl_conf->pools[0];
        else
                m_shm->pool = EM_POOL_DEFAULT;
 
        APPL_PRINT("\n"
                   "***********************************************************\n"
                   "EM APPLICATION: '%s' initializing:\n"
                   "  %s: %s() - EM-core:%d\n"
                   "  Application running on %u EM-cores (procs:%u, threads:%u)\n"
                   "  using event pool:%" PRI_POOL "\n"
                   "***********************************************************\n"
                   "\n",
                   appl_conf->name, NO_PATH(__FILE__), __func__, em_core_id(),
                   appl_conf->core_count, appl_conf->num_procs, appl_conf->num_threads,
                   m_shm->pool);
 
        test_fatal_if(m_shm->pool == EM_POOL_UNDEF,
                      "Undefined application event pool!");
 
        /* Create EO */
        eo = em_eo_create(APP_EO_NAME,
                          (em_start_func_t)app_eo_start,
                          (em_start_local_func_t)app_eo_start_local,
                          (em_stop_func_t)app_eo_stop, NULL,
                          (em_receive_func_t)app_eo_receive,
                          &m_shm->eo_context);
        test_fatal_if(eo == EM_EO_UNDEF, "Failed to create EO!");
        eo_ctx = &m_shm->eo_context;
 
        /* one basic queue */
        queue = em_queue_create("Timer hello Q",
                                EM_QUEUE_TYPE_PARALLEL,
                                EM_QUEUE_PRIO_NORMAL,
                                EM_QUEUE_GROUP_DEFAULT, NULL);
        stat = em_eo_add_queue_sync(eo, queue);
        test_fatal_if(stat != EM_OK, "Failed to create queue!");
        m_shm->eo_q = queue;
 
        /*
         * Create shared timer and store handle in shared memory.
         * Accept all defaults.
         */
        em_timer_attr_init(&attr);
        strncpy(attr.name, "ExampleTimer", EM_TIMER_NAME_LEN);
        m_shm->tmr = em_timer_create(&attr);
        test_fatal_if(m_shm->tmr == EM_TIMER_UNDEF, "Failed to create timer!");
 
        /* Start EO */
        stat = em_eo_start_sync(eo, NULL, NULL);
        test_fatal_if(stat != EM_OK, "Failed to start EO!");
 
        /* create periodic timer */
        eo_ctx->periodic_tmo = em_tmo_create(m_shm->tmr, EM_TMO_FLAG_PERIODIC,
                                             eo_ctx->my_q);
        test_fatal_if(eo_ctx->periodic_tmo == EM_TMO_UNDEF, "Can't allocate tmo!\n");
 
        /* allocate timeout event */
        event = em_alloc(sizeof(app_msg_t), EM_EVENT_TYPE_SW, m_shm->pool);
        test_fatal_if(event == EM_EVENT_UNDEF, "Can't allocate event!\n");
 
        msg = em_event_pointer(event);
        msg->command = APP_CMD_TMO;
        msg->tmo = eo_ctx->periodic_tmo;
        msg->count = 0;
        eo_ctx->hz = em_timer_get_freq(m_shm->tmr); /* save for later */
        if (eo_ctx->hz < 1000) { /* sanity check */
                APPL_ERROR("WARNING - timer hz very low!\n");
        }
 
        /* pre-allocate random timeout */
        eo_ctx->random_tmo = em_tmo_create(m_shm->tmr, EM_TMO_FLAG_ONESHOT,
                                           eo_ctx->my_q);
        test_fatal_if(eo_ctx->random_tmo == EM_TMO_UNDEF, "Can't allocate tmo!\n");
 
        /* setup periodic timeout (the tick) */
        period = eo_ctx->hz / 1000; /* ticks for 1 ms */
        period *= APP_PERIOD_MS;
        stat = em_tmo_set_periodic(eo_ctx->periodic_tmo, 0, period, event);
        test_fatal_if(stat != EM_OK, "Can't activate tmo!\n");
}
 
void test_stop(const appl_conf_t *appl_conf)
{
        const int core = em_core_id();
        em_status_t ret;
        em_eo_t eo;
 
        (void)appl_conf;
 
        APPL_PRINT("%s() on EM-core %d\n", __func__, core);
 
        eo = em_eo_find(APP_EO_NAME);
        test_fatal_if(eo == EM_EO_UNDEF, "Could not find EO:%s", APP_EO_NAME);
 
        ret = em_eo_stop_sync(eo);
        test_fatal_if(ret != EM_OK,
                      "EO:%" PRI_EO " stop:%" PRI_STAT "", eo, ret);
        ret = em_eo_delete(eo);
        test_fatal_if(ret != EM_OK,
                      "EO:%" PRI_EO " delete:%" PRI_STAT "", eo, ret);
 
        ret = em_timer_delete(m_shm->tmr);
        test_fatal_if(ret != EM_OK,
                      "Timer:%" PRI_TMR " delete:%" PRI_STAT "",
                      m_shm->tmr, ret);
}
 
void test_term(const appl_conf_t *appl_conf)
{
        (void)appl_conf;
        int core = em_core_id();
 
        APPL_PRINT("%s() on EM-core %d\n", __func__, core);
 
        if (m_shm != NULL) {
                env_shared_free(m_shm);
                m_shm = NULL;
                em_unregister_error_handler();
        }
}
 
/**
 * @private
 *
 * EO start function.
 */
static em_status_t app_eo_start(app_eo_ctx_t *eo_ctx, em_eo_t eo,
                                const em_eo_conf_t *conf)
{
        em_timer_attr_t attr;
        em_timer_t tmr;
        int num_timers;
 
        (void)eo;
        (void)conf;
 
        APPL_PRINT("EO start\n");
 
        /* print timer info */
        num_timers = em_timer_get_all(&tmr, 1);
        APPL_PRINT("System has %d timer(s)\n", num_timers);
 
        if (em_timer_get_attr(m_shm->tmr, &attr) != EM_OK) {
                APPL_ERROR("Can't get timer info!\n");
                return EM_ERR_BAD_ID;
        }
 
        APPL_PRINT("Timer \"%s\" info:\n", attr.name);
        APPL_PRINT("  -resolution: %" PRIu64 " ns\n", attr.resparam.res_ns);
        APPL_PRINT("  -max_tmo: %" PRIu64 " us\n", attr.resparam.max_tmo / 1000);
        APPL_PRINT("  -min_tmo: %" PRIu64 " us\n", attr.resparam.min_tmo / 1000);
        APPL_PRINT("  -num_tmo: %d\n", attr.num_tmo);
        APPL_PRINT("  -clk_src: %d\n", attr.resparam.clk_src);
        APPL_PRINT("  -tick Hz: %" PRIu64 " hz\n",
                   em_timer_get_freq(m_shm->tmr));
 
        /* init local EO context */
        eo_ctx->my_q = m_shm->eo_q;
 
        return EM_OK;
}
 
/**
 * @private
 *
 * EO per thread start function.
 *
 */
static em_status_t app_eo_start_local(app_eo_ctx_t *eo_ctx, em_eo_t eo)
{
        (void)eo_ctx;
        (void)eo;
 
        APPL_PRINT("EO local start\n");
 
        /* per-thread random seed */
        m_randseed = (unsigned int)em_timer_current_tick(m_shm->tmr);
 
        /* with a low frequency timer we actually get the same seed! */
 
        return EM_OK;
}
 
/**
 * @private
 *
 * EO stop function.
 *
 */
static em_status_t app_eo_stop(app_eo_ctx_t *eo_ctx, em_eo_t eo)
{
        em_event_t event = EM_EVENT_UNDEF;
        em_status_t ret;
 
        APPL_PRINT("EO stop\n");
 
        /* cancel and delete ongoing timeouts */
        if (eo_ctx->periodic_tmo != EM_TMO_UNDEF) {
                em_tmo_delete(eo_ctx->periodic_tmo, &event);
                if (event != EM_EVENT_UNDEF)
                        em_free(event);
        }
        if (eo_ctx->random_tmo != EM_TMO_UNDEF) {
                event = EM_EVENT_UNDEF;
                em_tmo_delete(eo_ctx->random_tmo, &event);
                if (event != EM_EVENT_UNDEF)
                        em_free(event);
        }
 
        /* remove and delete all of the EO's queues */
        ret = em_eo_remove_queue_all_sync(eo, EM_TRUE);
        test_fatal_if(ret != EM_OK,
                      "EO remove queue all:%" PRI_STAT " EO:%" PRI_EO "",
                      ret, eo);
 
        return EM_OK;
}
 
/**
 * @private
 *
 * EO receive function. This runs the example app after initialization.
 *
 * Prints tick-tock at every periodic timeout and in parallel runs random
 * timeouts that trigger printing of a random quote.
 *
 */
static void app_eo_receive(app_eo_ctx_t *eo_ctx, em_event_t event,
                           em_event_type_t type, em_queue_t queue,
                           void *q_ctx)
{
        int reuse = 0;
        em_status_t ret;
 
        (void)queue;
        (void)q_ctx;
 
        if (unlikely(appl_shm->exit_flag)) {
                em_free(event);
                return;
        }
 
        if (type == EM_EVENT_TYPE_SW) {
                app_msg_t *msgin = (app_msg_t *)em_event_pointer(event);
 
                switch (msgin->command) {
                case APP_CMD_TMO:
                        /* print tick-tock */
                        msgin->count++;
                        if (msgin->count & 1)
                                APPL_PRINT("%" PRIu64 ". ",
                                           (msgin->count / 2) + 1);
                        APPL_PRINT((msgin->count & 1) ? "tick\n" : "tock\n");
 
                        /* ack periodic timeout, re-use the same event */
                        ret = em_tmo_ack(msgin->tmo, event);
                        test_fatal_if(ret != EM_OK,
                                      "em_tmo_ack():%" PRI_STAT, ret);
 
                        reuse = 1; /* do not free this event */
 
                        /* get random timeouts going after 10th message */
                        if (msgin->count == 10)
                                new_rand_timeout(eo_ctx);
                        break;
 
                case APP_CMD_HELLO:
                        APPL_PRINT("%s\n\n", msgin->text);
                        /* set next timeout */
                        new_rand_timeout(eo_ctx);
                        break;
                default:
                        test_error(EM_ERROR_SET_FATAL(0xDEAD), 0xBEEF,
                                   "Invalid event!\n");
                }
        } else {
                test_error(EM_ERROR_SET_FATAL(0xDEAD), 0xBEEF,
                           "Invalid event type!\n");
        }
 
        /* normally free the received event */
        if (!reuse)
                em_free(event);
}
 
/* sets a new random timeout */
void new_rand_timeout(app_eo_ctx_t *eo_ctx)
{
        int rnd;
        app_msg_t *msg;
        uint64_t period;
        em_status_t stat;
 
        /* random timeouts allocate new event every time (could re-use) */
        em_event_t event = em_alloc(sizeof(app_msg_t), EM_EVENT_TYPE_SW,
                                    m_shm->pool);
        if (!event) {
                test_error(EM_ERROR_SET_FATAL(0xDEAD), 0xBEEF,
                           "Can't allocate event!");
        }
 
        msg = em_event_pointer(event);
        msg->command = APP_CMD_HELLO;
 
        /* new timeout period APP_TIMEOUT_MIN_MS ... APP_TIMEOUT_MODULO */
        do {
                rnd = rand_r(&m_randseed);
                rnd %= APP_TIMEOUT_MODULO_MS;
 
        } while (rnd < APP_TIMEOUT_MIN_MS);
 
        snprintf(msg->text, APP_MAX_TEXT_LEN, "%d ms gone!\n", rnd);
        msg->text[APP_MAX_TEXT_LEN - 1] = 0;
 
        APPL_PRINT("Meditation time: what can you do in %d ms?\n", rnd);
 
        period = eo_ctx->hz / 1000;
        period *= rnd; /* rnd x ms */
 
        /* Alternate between set_rel() and set_abs(), roughly half of each */
        if (rnd > (APP_TIMEOUT_MODULO_MS + APP_TIMEOUT_MIN_MS) / 2)
                stat = em_tmo_set_rel(eo_ctx->random_tmo, period, event);
        else
                stat = em_tmo_set_abs(eo_ctx->random_tmo,
                                      em_timer_current_tick(m_shm->tmr) +
                                      period, event);
        if (stat != EM_OK)
                test_error(EM_ERROR_SET_FATAL(0xDEAD), 0xBEEF,
                           "Can't activate tmo!\n");
}