ctdb/utils/ping_pong/ping_pong.c

   1 /*
   2    A ping-pong fcntl byte range lock test
   3
   4    Copyright (C) Andrew Tridgell 2002
   5    Copyright (C) Michael Adam 2012
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 /*
  22   This measures the ping-pong byte range lock latency. It is
  23   especially useful on a cluster of nodes sharing a common lock
  24   manager as it will give some indication of the lock managers
  25   performance under stress.
  26
  27   tridge@samba.org, February 2002
  28
  29 */
  30
  31 #define _XOPEN_SOURCE 500
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <sys/time.h>
  36 #include <time.h>
  37 #include <errno.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <fcntl.h>
  41 #include <sys/mman.h>
  42 #include <stdbool.h>
  43
  44 static struct timeval tp1,tp2;
  45
  46 static int do_reads, do_writes, use_mmap, do_check, do_brl_test;
  47
  48 static void start_timer(void)
  49 {
  50         gettimeofday(&tp1,NULL);
  51 }
  52
  53 static double end_timer(void)
  54 {
  55         gettimeofday(&tp2,NULL);
  56         return (tp2.tv_sec + (tp2.tv_usec*1.0e-6)) -
  57                 (tp1.tv_sec + (tp1.tv_usec*1.0e-6));
  58 }
  59
  60 /* lock a byte range in a open file */
  61 static int lock_range(int fd, int offset, int len, bool wait)
  62 {
  63         struct flock lock;
  64
  65         lock.l_type = F_WRLCK;
  66         lock.l_whence = SEEK_SET;
  67         lock.l_start = offset;
  68         lock.l_len = len;
  69         lock.l_pid = 0;
  70
  71         return fcntl(fd, wait ? F_SETLKW : F_SETLK, &lock);
  72 }
  73
  74 /* check whether we could place a lock */
  75 static int check_lock(int fd, int offset, int len)
  76 {
  77         struct flock lock;
  78         int ret;
  79
  80         lock.l_type = F_WRLCK;
  81         lock.l_whence = SEEK_SET;
  82         lock.l_start = offset;
  83         lock.l_len = len;
  84         lock.l_pid = 0;
  85
  86         ret = fcntl(fd, F_GETLK, &lock);
  87         if (ret != 0) {
  88                 printf("error calling fcntl F_GETLCK: %s\n", strerror(errno));
  89                 return -1;
  90         }
  91
  92         if (lock.l_type == F_UNLCK) {
  93                 /* we would be able to place the lock */
  94                 return 0;
  95         }
  96
  97         /* we would not be able to place lock */
  98         printf("check_lock failed: lock held: "
  99                "pid='%d', type='%d', start='%d', len='%d'\n",
 100                (int)lock.l_pid, (int)lock.l_type, (int)lock.l_start, (int)lock.l_len);
 101         return 1;
 102 }
 103
 104 /* unlock a byte range in a open file */
 105 static int unlock_range(int fd, int offset, int len)
 106 {
 107         struct flock lock;
 108
 109         lock.l_type = F_UNLCK;
 110         lock.l_whence = SEEK_SET;
 111         lock.l_start = offset;
 112         lock.l_len = len;
 113         lock.l_pid = 0;
 114
 115         return fcntl(fd,F_SETLKW,&lock);
 116 }
 117
 118 /* run the ping pong test on fd */
 119 static void ping_pong(int fd, int num_locks)
 120 {
 121         unsigned count = 0;
 122         int i=0, loops=0;
 123         unsigned char *val;
 124         unsigned char incr=0, last_incr=0;
 125         unsigned char *p = NULL;
 126         int ret;
 127
 128         ret = ftruncate(fd, num_locks+1);
 129         if (ret == -1) {
 130                 printf("ftruncate failed: %s\n", strerror(errno));
 131                 return;
 132         }
 133
 134         if (use_mmap) {
 135                 p = mmap(NULL, num_locks+1, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
 136                 if (p == MAP_FAILED) {
 137                         printf("mmap failed: %s\n", strerror(errno));
 138                         return;
 139                 }
 140         }
 141
 142         val = (unsigned char *)calloc(num_locks+1, sizeof(unsigned char));
 143         if (val == NULL) {
 144                 printf("calloc failed\n");
 145                 if (use_mmap) {
 146                         munmap(p, num_locks+1);
 147                 }
 148                 return;
 149         }
 150
 151         start_timer();
 152
 153         ret = lock_range(fd, 0, 1, true);
 154         if (ret != 0) {
 155                 printf("initial lock at 0 failed! - %s\n", strerror(errno));
 156                 goto done;
 157         }
 158
 159         i = 0;
 160
 161         while (1) {
 162                 if (lock_range(fd, (i+1) % num_locks, 1, true) != 0) {
 163                         printf("lock at %d failed! - %s\n",
 164                                (i+1) % num_locks, strerror(errno));
 165                 }
 166                 if (do_check) {
 167                         ret = check_lock(fd, i, 1);
 168                         if (ret != 0) {
 169                                 goto done;
 170                         }
 171                 }
 172                 if (do_reads) {
 173                         unsigned char c;
 174                         if (use_mmap) {
 175                                 c = p[i];
 176                         } else if (pread(fd, &c, 1, i) != 1) {
 177                                 printf("read failed at %d\n", i);
 178                         }
 179                         incr = c - val[i];
 180                         val[i] = c;
 181                 }
 182                 if (do_writes) {
 183                         char c = val[i] + 1;
 184                         if (use_mmap) {
 185                                 p[i] = c;
 186                         } else if (pwrite(fd, &c, 1, i) != 1) {
 187                                 printf("write failed at %d\n", i);
 188                         }
 189                 }
 190                 if (unlock_range(fd, i, 1) != 0) {
 191                         printf("unlock at %d failed! - %s\n",
 192                                i, strerror(errno));
 193                 }
 194                 i = (i+1) % num_locks;
 195                 count++;
 196                 if (loops > num_locks && incr != last_incr) {
 197                         last_incr = incr;
 198                         printf("data increment = %u\n", incr);
 199                         fflush(stdout);
 200                 }
 201                 if (end_timer() > 1.0) {
 202                         printf("%8u locks/sec\r",
 203                                (unsigned)(2*count/end_timer()));
 204                         fflush(stdout);
 205                         start_timer();
 206                         count=0;
 207                 }
 208                 loops++;
 209         }
 210
 211 done:
 212         if (use_mmap) {
 213                 munmap(p, num_locks+1);
 214         }
 215         free(val);
 216 }
 217
 218 static void usage(void)
 219 {
 220         printf("ping_pong -rwmc <file> <num_locks>\n");
 221         printf("ping_pong -l <file>\n\n");
 222         printf("Options\n");
 223         printf(" -r    do reads\n");
 224         printf(" -w    do writes\n");
 225         printf(" -m    use mmap\n");
 226         printf(" -c    check locks\n");
 227         printf(" -l    test for working byte range locks\n");
 228 }
 229
 230 int main(int argc, char *argv[])
 231 {
 232         char *fname;
 233         int fd, num_locks;
 234         int c;
 235
 236         while ((c = getopt(argc, argv, "rwmcl")) != -1) {
 237                 switch (c){
 238                 case 'w':
 239                         do_writes = 1;
 240                         break;
 241                 case 'r':
 242                         do_reads = 1;
 243                         break;
 244                 case 'm':
 245                         use_mmap = 1;
 246                         break;
 247                 case 'c':
 248                         do_check = 1;
 249                         break;
 250                 case 'l':
 251                         do_brl_test = 1;
 252                         break;
 253                 default:
 254                         fprintf(stderr, "Unknown option '%c'\n", c);
 255                         exit(1);
 256                 }
 257         }
 258
 259         argv += optind;
 260         argc -= optind;
 261
 262         if (argc < 1) {
 263                 usage();
 264                 exit(1);
 265         }
 266
 267         fname = argv[0];
 268
 269         fd = open(fname, O_CREAT|O_RDWR, 0600);
 270         if (fd == -1) {
 271                 exit(1);
 272         }
 273
 274         if (do_brl_test) {
 275                 if (lock_range(fd, 0, 0, false) != 0) {
 276                         printf("file already locked, calling check_lock to tell us who has it locked:\n");
 277                         (void)check_lock(fd, 0, 0);
 278                         printf("Working POSIX byte range locks\n");
 279                         exit(0);
 280                 }
 281
 282                 printf("Holding lock, press any key to continue...\n");
 283                 printf("You should run the same command on another node now.\n");
 284                 (void)getchar();
 285                 printf("Good bye.\n");
 286                 exit(0);
 287         }
 288
 289         if (argc < 2) {
 290                 usage();
 291                 exit(1);
 292         }
 293
 294         num_locks = atoi(argv[1]);
 295         if (num_locks <= 0) {
 296                 printf("num_locks should be > 0\n");
 297                 exit(1);
 298         }
 299
 300         ping_pong(fd, num_locks);
 301
 302         return 0;
 303 }