ceph/src/dpdk/examples/performance-thread/pthread_shim/main.c

   1
   2 /*-
   3  *   BSD LICENSE
   4  *
   5  *   Copyright(c) 2015 Intel Corporation. All rights reserved.
   6  *   All rights reserved.
   7  *
   8  *   Redistribution and use in source and binary forms, with or without
   9  *   modification, are permitted provided that the following conditions
  10  *   are met:
  11  *
  12  *     * Redistributions of source code must retain the above copyright
  13  *       notice, this list of conditions and the following disclaimer.
  14  *     * Redistributions in binary form must reproduce the above copyright
  15  *       notice, this list of conditions and the following disclaimer in
  16  *       the documentation and/or other materials provided with the
  17  *       distribution.
  18  *     * Neither the name of Intel Corporation nor the names of its
  19  *       contributors may be used to endorse or promote products derived
  20  *       from this software without specific prior written permission.
  21  *
  22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #define _GNU_SOURCE
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <stdint.h>
  39 #include <inttypes.h>
  40 #include <sys/types.h>
  41 #include <string.h>
  42 #include <sys/queue.h>
  43 #include <stdarg.h>
  44 #include <errno.h>
  45 #include <getopt.h>
  46 #include <unistd.h>
  47 #include <sched.h>
  48 #include <pthread.h>
  49
  50 #include <rte_common.h>
  51 #include <rte_lcore.h>
  52 #include <rte_per_lcore.h>
  53 #include <rte_timer.h>
  54
  55 #include "lthread_api.h"
  56 #include "lthread_diag_api.h"
  57 #include "pthread_shim.h"
  58
  59 #define DEBUG_APP 0
  60 #define HELLOW_WORLD_MAX_LTHREADS 10
  61
  62 __thread int print_count;
  63 __thread pthread_mutex_t print_lock;
  64
  65 __thread pthread_mutex_t exit_lock;
  66 __thread pthread_cond_t exit_cond;
  67
  68 /*
  69  * A simple thread that demonstrates use of a mutex, a condition
  70  * variable, thread local storage, explicit yield, and thread exit.
  71  *
  72  * The thread uses a mutex to protect a shared counter which is incremented
  73  * and then it waits on condition variable before exiting.
  74  *
  75  * The thread argument is stored in and retrieved from TLS, using
  76  * the pthread key create, get and set specific APIs.
  77  *
  78  * The thread yields while holding the mutex, to provide opportunity
  79  * for other threads to contend.
  80  *
  81  * All of the pthread API functions used by this thread are actually
  82  * resolved to corresponding lthread functions by the pthread shim
  83  * implemented in pthread_shim.c
  84  */
  85 void *helloworld_pthread(void *arg);
  86 void *helloworld_pthread(void *arg)
  87 {
  88         pthread_key_t key;
  89
  90         /* create a key for TLS */
  91         pthread_key_create(&key, NULL);
  92
  93         /* store the arg in TLS */
  94         pthread_setspecific(key, arg);
  95
  96         /* grab lock and increment shared counter */
  97         pthread_mutex_lock(&print_lock);
  98         print_count++;
  99
 100         /* yield thread to give opportunity for lock contention */
 101         pthread_yield();
 102
 103         /* retrieve arg from TLS */
 104         uint64_t thread_no = (uint64_t) pthread_getspecific(key);
 105
 106         printf("Hello - lcore = %d count = %d thread_no = %d thread_id = %p\n",
 107                         sched_getcpu(),
 108                         print_count,
 109                         (int) thread_no,
 110                         (void *)pthread_self());
 111
 112         /* release the lock */
 113         pthread_mutex_unlock(&print_lock);
 114
 115         /*
 116          * wait on condition variable
 117          * before exiting
 118          */
 119         pthread_mutex_lock(&exit_lock);
 120         pthread_cond_wait(&exit_cond, &exit_lock);
 121         pthread_mutex_unlock(&exit_lock);
 122
 123         /* exit */
 124         pthread_exit((void *) thread_no);
 125 }
 126
 127
 128 /*
 129  * This is the initial thread
 130  *
 131  * It demonstrates pthread, mutex and condition variable creation,
 132  * broadcast and pthread join APIs.
 133  *
 134  * This initial thread must always start life as an lthread.
 135  *
 136  * This thread creates many more threads then waits a short time
 137  * before signalling them to exit using a broadcast.
 138  *
 139  * All of the pthread API functions used by this thread are actually
 140  * resolved to corresponding lthread functions by the pthread shim
 141  * implemented in pthread_shim.c
 142  *
 143  * After all threads have finished the lthread scheduler is shutdown
 144  * and normal pthread operation is restored
 145  */
 146 __thread pthread_t tid[HELLOW_WORLD_MAX_LTHREADS];
 147
 148 static void initial_lthread(void *args);
 149 static void initial_lthread(void *args __attribute__((unused)))
 150 {
 151         int lcore = (int) rte_lcore_id();
 152         /*
 153          *
 154          * We can now enable pthread API override
 155          * and start to use the pthread APIs
 156          */
 157         pthread_override_set(1);
 158
 159         uint64_t i;
 160
 161         /* initialize mutex for shared counter */
 162         print_count = 0;
 163         pthread_mutex_init(&print_lock, NULL);
 164
 165         /* initialize mutex and condition variable controlling thread exit */
 166         pthread_mutex_init(&exit_lock, NULL);
 167         pthread_cond_init(&exit_cond, NULL);
 168
 169         /* spawn a number of threads */
 170         for (i = 0; i < HELLOW_WORLD_MAX_LTHREADS; i++) {
 171
 172                 /*
 173                  * Not strictly necessary but
 174                  * for the sake of this example
 175                  * use an attribute to pass the desired lcore
 176                  */
 177                 pthread_attr_t attr;
 178                 cpu_set_t cpuset;
 179
 180                 CPU_ZERO(&cpuset);
 181                 CPU_SET(lcore, &cpuset);
 182                 pthread_attr_init(&attr);
 183                 pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
 184
 185                 /* create the thread */
 186                 pthread_create(&tid[i], &attr, helloworld_pthread, (void *) i);
 187         }
 188
 189         /* wait for 1s to allow threads
 190          * to block on the condition variable
 191          * N.B. nanosleep() is resolved to lthread_sleep()
 192          * by the shim.
 193          */
 194         struct timespec time;
 195
 196         time.tv_sec = 1;
 197         time.tv_nsec = 0;
 198         nanosleep(&time, NULL);
 199
 200         /* wake up all the threads */
 201         pthread_cond_broadcast(&exit_cond);
 202
 203         /* wait for them to finish */
 204         for (i = 0; i < HELLOW_WORLD_MAX_LTHREADS; i++) {
 205
 206                 uint64_t thread_no;
 207
 208                 pthread_join(tid[i], (void *) &thread_no);
 209                 if (thread_no != i)
 210                         printf("error on thread exit\n");
 211         }
 212
 213         pthread_cond_destroy(&exit_cond);
 214         pthread_mutex_destroy(&print_lock);
 215         pthread_mutex_destroy(&exit_lock);
 216
 217         /* shutdown the lthread scheduler */
 218         lthread_scheduler_shutdown(rte_lcore_id());
 219         lthread_detach();
 220 }
 221
 222
 223
 224 /* This thread creates a single initial lthread
 225  * and then runs the scheduler
 226  * An instance of this thread is created on each thread
 227  * in the core mask
 228  */
 229 static int
 230 lthread_scheduler(void *args);
 231 static int
 232 lthread_scheduler(void *args __attribute__((unused)))
 233 {
 234         /* create initial thread  */
 235         struct lthread *lt;
 236
 237         lthread_create(&lt, -1, initial_lthread, (void *) NULL);
 238
 239         /* run the lthread scheduler */
 240         lthread_run();
 241
 242         /* restore genuine pthread operation */
 243         pthread_override_set(0);
 244         return 0;
 245 }
 246
 247 int main(int argc, char **argv)
 248 {
 249         int num_sched = 0;
 250
 251         /* basic DPDK initialization is all that is necessary to run lthreads*/
 252         int ret = rte_eal_init(argc, argv);
 253
 254         if (ret < 0)
 255                 rte_exit(EXIT_FAILURE, "Invalid EAL parameters\n");
 256
 257         /* enable timer subsystem */
 258         rte_timer_subsystem_init();
 259
 260 #if DEBUG_APP
 261         lthread_diagnostic_set_mask(LT_DIAG_ALL);
 262 #endif
 263
 264         /* create a scheduler on every core in the core mask
 265          * and launch an initial lthread that will spawn many more.
 266          */
 267         unsigned lcore_id;
 268
 269         for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
 270                 if (rte_lcore_is_enabled(lcore_id))
 271                         num_sched++;
 272         }
 273
 274         /* set the number of schedulers, this forces all schedulers synchronize
 275          * before entering their main loop
 276          */
 277         lthread_num_schedulers_set(num_sched);
 278
 279         /* launch all threads */
 280         rte_eal_mp_remote_launch(lthread_scheduler, (void *)NULL, CALL_MASTER);
 281
 282         /* wait for threads to stop */
 283         RTE_LCORE_FOREACH_SLAVE(lcore_id) {
 284                 rte_eal_wait_lcore(lcore_id);
 285         }
 286         return 0;
 287 }