helgrind/tests/tc08_hbl2.c

   1
   2 /* FIXME: this is basically a bad test as it is scheduling-
   3    sensitive.  Sometimes the output is:
   4
   5    child: new value 6
   6    child: new value 10
   7    done, x = 10
   8
   9    and sometimes
  10
  11    child: new value 10
  12    done, x = 10
  13 */
  14
  15 #include <pthread.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19
  20 /* Simple test program, no race.  Parent writes atomically to a counter
  21    whilst child reads it.  When counter reaches a prearranged value,
  22    child joins back to parent.  Parent (writer) uses hardware bus lock;
  23    child is only reading and so does not need to use a bus lock. */
  24
  25 #undef PLAT_x86_darwin
  26 #undef PLAT_amd64_darwin
  27 #undef PLAT_x86_freebsd
  28 #undef PLAT_amd64_freebsd
  29 #undef PLAT_arm64_freebsd
  30 #undef PLAT_x86_linux
  31 #undef PLAT_amd64_linux
  32 #undef PLAT_ppc32_linux
  33 #undef PLAT_ppc64_linux
  34 #undef PLAT_arm_linux
  35 #undef PLAT_arm64_linux
  36 #undef PLAT_s390x_linux
  37 #undef PLAT_mips32_linux
  38 #undef PLAT_mips64_linux
  39 #undef PLAT_x86_solaris
  40 #undef PLAT_amd64_solaris
  41
  42 #if defined(__APPLE__) && defined(__i386__)
  43 #  define PLAT_x86_darwin 1
  44 #elif defined(__APPLE__) && defined(__x86_64__)
  45 #  define PLAT_amd64_darwin 1
  46 #elif defined(__FreeBSD__) && defined(__i386__)
  47 #  define PLAT_x86_freebsd 1
  48 #elif defined(__FreeBSD__) && defined(__amd64__)
  49 #  define PLAT_amd64_freebsd 1
  50 #elif defined(__FreeBSD__) && defined(__aarch64__)
  51 #  define PLAT_arm64_freebsd 1
  52 #elif defined(__linux__) && defined(__i386__)
  53 #  define PLAT_x86_linux 1
  54 #elif defined(__linux__) && defined(__x86_64__)
  55 #  define PLAT_amd64_linux 1
  56 #elif defined(__linux__) && defined(__powerpc__) && !defined(__powerpc64__)
  57 #  define PLAT_ppc32_linux 1
  58 #elif defined(__linux__) && defined(__powerpc__) && defined(__powerpc64__)
  59 #  define PLAT_ppc64_linux 1
  60 #elif defined(__linux__) && defined(__arm__) && !defined(__aarch64__)
  61 #  define PLAT_arm_linux 1
  62 #elif defined(__linux__) && defined(__aarch64__) && !defined(__arm__)
  63 #  define PLAT_arm64_linux 1
  64 #elif defined(__linux__) && defined(__s390x__)
  65 #  define PLAT_s390x_linux 1
  66 #elif defined(__linux__) && defined(__mips__)
  67 #if (__mips==64)
  68 #  define PLAT_mips64_linux 1
  69 #else
  70 #  define PLAT_mips32_linux 1
  71 #endif
  72 #elif defined(__linux__) && defined(__nanomips__)
  73 #  define PLAT_nanomips_linux 1
  74 #elif defined(__sun__) && defined(__i386__)
  75 #  define PLAT_x86_solaris 1
  76 #elif defined(__sun__) && defined(__x86_64__)
  77 #  define PLAT_amd64_solaris 1
  78 #endif
  79
  80
  81 #if defined(PLAT_amd64_linux) || defined(PLAT_x86_linux) \
  82     || defined(PLAT_amd64_darwin) || defined(PLAT_x86_darwin) \
  83     || defined(PLAT_amd64_solaris) || defined(PLAT_x86_solaris) \
  84     || defined(PLAT_amd64_freebsd) || defined(PLAT_x86_freebsd)
  85 #  define INC(_lval,_lqual)          \
  86       __asm__ __volatile__ ( \
  87       "lock ; incl (%0)" : /*out*/ : /*in*/"r"(&(_lval)) : "memory", "cc" )
  88 #elif defined(PLAT_ppc32_linux) || defined(PLAT_ppc64_linux)
  89 #  define INC(_lval,_lqual)               \
  90    __asm__ __volatile__(                  \
  91       "1:\n"                              \
  92       "        lwarx 15,0,%0\n"           \
  93       "        addi 15,15,1\n"            \
  94       "        stwcx. 15,0,%0\n"          \
  95       "        bne- 1b\n"                 \
  96       : /*out*/ : /*in*/ "b"(&(_lval))    \
  97       : /*trash*/ "r15", "cr0", "memory"  \
  98    )
  99 #elif defined(PLAT_arm_linux)
 100 #  define INC(_lval,_lqual) \
 101   __asm__ __volatile__( \
 102       "1:\n"                                 \
 103       "        ldrex r8, [%0, #0]\n"         \
 104       "        add   r8, r8, #1\n"           \
 105       "        strex r9, r8, [%0, #0]\n"     \
 106       "        cmp   r9, #0\n"               \
 107       "        bne   1b\n"                   \
 108       : /*out*/ : /*in*/ "r"(&(_lval))       \
 109       : /*trash*/ "r8", "r9", "cc", "memory" \
 110   );
 111 #elif defined(PLAT_arm64_linux) || defined(PLAT_arm64_freebsd)
 112 #  define INC(_lval,_lqual) \
 113   __asm__ __volatile__( \
 114       "1:\n"                                 \
 115       "        ldxr  w8, [%0, #0]\n"         \
 116       "        add   w8, w8, #1\n"           \
 117       "        stxr  w9, w8, [%0, #0]\n"     \
 118       "        cmp   w9, #0\n"               \
 119       "        bne   1b\n"                   \
 120       : /*out*/ : /*in*/ "r"(&(_lval))       \
 121       : /*trash*/ "x8", "x9", "cc", "memory" \
 122   );
 123 #elif defined(PLAT_s390x_linux)
 124 #  define INC(_lval,_lqual) \
 125    __asm__ __volatile__( \
 126       "1: l     0,%0\n"                            \
 127       "   lr    1,0\n"                             \
 128       "   ahi   1,1\n"                             \
 129       "   cs    0,1,%0\n"                          \
 130       "   jl    1b\n"                              \
 131       : "+m" (_lval) :: "cc", "0","1" \
 132    )
 133 #elif defined(PLAT_mips32_linux) || defined(PLAT_mips64_linux)
 134 #  define INC(_lval,_lqual)                         \
 135      __asm__ __volatile__ (                         \
 136       "1:\n"                                        \
 137       "        move  $t0, %0\n"                     \
 138       "        ll    $t1, 0($t0)\n"                 \
 139       "        addiu $t1, $t1, 1\n"                 \
 140       "        sc    $t1, 0($t0)\n"                 \
 141       "        beqz  $t1, 1b\n"                     \
 142       : /*out*/ : /*in*/ "r"(&(_lval))              \
 143       : /*trash*/ "t0", "t1", "memory"              \
 144         )
 145 #elif defined(PLAT_nanomips_linux)
 146 #  define INC(_lval,_lqual)                         \
 147      __asm__ __volatile__ (                         \
 148       "1:\n"                                        \
 149       "        move $t0, %0\n"                      \
 150       "        ll $t1, 0($t0)\n"                    \
 151       "        addiu $t1, $t1, 1\n"                 \
 152       "        sc $t1, 0($t0)\n"                    \
 153       "        beqc $t1, $zero, 1b\n"               \
 154       : /*out*/ : /*in*/ "r"(&(_lval))              \
 155       : /*trash*/ "$t0", "$t1", "memory"            \
 156    )
 157 #else
 158 #  error "Fix Me for this platform"
 159 #endif
 160
 161
 162
 163 #define LIMIT 10
 164
 165 volatile int x = 0;
 166
 167 void* child_fn ( void* arg )
 168 {
 169    int q = 0;
 170    int oldx = 0;
 171    struct timespec ts = { 0, 1000 * 1000 };
 172
 173    while (1) {
 174       q = (x >= LIMIT);
 175       if (x != oldx) {
 176          oldx = x;
 177          printf("child: new value %d\n", oldx);
 178          fflush(stdout);
 179       }
 180       if (q) break;
 181       nanosleep(&ts, 0);
 182    }
 183    return NULL;
 184 }
 185
 186 int main ( void )
 187 {
 188    pthread_t child;
 189    int i;
 190
 191    if (pthread_create(&child, NULL, child_fn, NULL)) {
 192       perror("pthread_create");
 193       exit(1);
 194    }
 195
 196    for (i = 0; i < LIMIT; i++) {
 197       INC(x, "main");
 198       if (i == 5) sleep(1); /* make sure child doesn't starve */
 199    }
 200
 201    if (pthread_join(child, NULL)) {
 202       perror("pthread join");
 203       exit(1);
 204    }
 205
 206    printf("done, x = %d\n", x);
 207
 208    return 0;
 209 }