gdbserver_tests/sleepers.c

   1 #define _GNU_SOURCE
   2 #include <string.h>
   3 #include <pthread.h>
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6 #include <fcntl.h>
   7 #include <unistd.h>
   8 #include <sys/types.h>
   9 #include <sys/syscall.h>
  10 #include <sched.h>
  11
  12 static int loops = 15; // each thread+main will do this amount of loop
  13 static int sleepms = 1000; // in each loop, will sleep "sleepms" milliseconds
  14 static int burn = 0; // after each sleep, will burn cpu in a tight 'burn' loop
  15
  16
  17 static pid_t gettid()
  18 {
  19 #ifdef __NR_gettid
  20    return syscall(__NR_gettid);
  21 #else
  22    return getpid();
  23 #endif
  24 }
  25 // will be invoked from gdb.
  26 static void whoami(char *msg) __attribute__((unused));
  27 static void whoami(char *msg)
  28 {
  29    fprintf(stderr, "pid %d Thread %d %s\n", getpid(), gettid(), msg);
  30    fflush(stderr);
  31 }
  32
  33
  34 static void do_burn ()
  35 {
  36    int i;
  37    int loopnr = 0;
  38    // one single line for the below, to ensure interrupt on this line.
  39    for (i = 0; i < burn; i++) loopnr++;
  40 }
  41
  42 static int thread_ready = 0;
  43 static pthread_cond_t ready = PTHREAD_COND_INITIALIZER;
  44 static pthread_mutex_t ready_mutex = PTHREAD_MUTEX_INITIALIZER;
  45 static void signal_ready (void)
  46 {
  47    int rc;
  48    rc = pthread_mutex_lock(&ready_mutex);
  49    if (rc != 0)
  50       fprintf(stderr, "signal_ready lock error %d_n", rc);
  51    thread_ready = 1;
  52    rc = pthread_cond_signal(&ready);
  53    if (rc != 0)
  54       fprintf(stderr, "signal_ready signal error %d_n", rc);
  55    rc = pthread_mutex_unlock(&ready_mutex);
  56    if (rc != 0)
  57       fprintf(stderr, "signal_ready unlock error %d_n", rc);
  58 }
  59
  60 struct spec {
  61    char *name;
  62    int sleep;
  63    int burn;
  64    int t;
  65 };
  66 static struct timeval t[4];
  67 static int nr_sleeper_or_burner = 0;
  68 static volatile int report_finished = 1;
  69 // set to 0 to have no finish msg (as order is non-deterministic)
  70 static void *sleeper_or_burner(void *v)
  71 {
  72    int i = 0;
  73    struct spec* s = (struct spec*)v;
  74
  75    fprintf(stderr, "%s ready to sleep and/or burn\n", s->name);
  76    fflush (stderr);
  77    signal_ready();
  78    nr_sleeper_or_burner++;
  79
  80    for (i = 0; i < loops; i++) {
  81       if (sleepms > 0 && s->sleep) {
  82          t[s->t].tv_sec = sleepms / 1000;
  83          t[s->t].tv_usec = (sleepms % 1000) * 1000;
  84          select (0, NULL, NULL, NULL, &t[s->t]);
  85       }
  86       if (burn > 0 && s->burn)
  87          do_burn();
  88    }
  89    if (report_finished) {
  90       fprintf(stderr, "%s finished to sleep and/or burn\n", s->name);
  91       fflush (stderr);
  92    }
  93    return NULL;
  94 }
  95
  96 // wait till a thread signals it is ready
  97 static void wait_ready(void)
  98 {
  99    int rc;
 100    rc = pthread_mutex_lock(&ready_mutex);
 101    if (rc != 0)
 102       fprintf(stderr, "wait_ready lock error %d_n", rc);
 103    while (! thread_ready && rc == 0) {
 104       rc = pthread_cond_wait(&ready, &ready_mutex);
 105       if (rc != 0)
 106          fprintf(stderr, "wait_ready wait error %d_n", rc);
 107    }
 108    thread_ready = 0;
 109    rc = pthread_mutex_unlock(&ready_mutex);
 110    if (rc != 0)
 111       fprintf(stderr, "wait_ready unlock error %d_n", rc);
 112 }
 113
 114 // We will lock ourselves on one single cpu.
 115 // This bypasses the unfairness of the Valgrind scheduler
 116 // when a multi-cpu machine has enough cpu to run all the
 117 // threads wanting to burn cpu.
 118 static void setaffinity(void)
 119 {
 120 #ifdef VGO_linux
 121    cpu_set_t single_cpu;
 122    CPU_ZERO(&single_cpu);
 123    CPU_SET(1, &single_cpu);
 124    (void) sched_setaffinity(0, sizeof(single_cpu), &single_cpu);
 125 #endif
 126    // GDBTD: equivalent for Darwin ?
 127 }
 128
 129 int main (int argc, char *argv[])
 130 {
 131   char *threads_spec;
 132   pthread_t ebbr, egll, zzzz;
 133   struct spec b, l, p, m;
 134   char *some_mem __attribute__((unused)) = malloc(100);
 135   setaffinity();
 136
 137   if (argc > 1)
 138      loops = atoi(argv[1]);
 139
 140   if (argc > 2)
 141      sleepms = atoi(argv[2]);
 142
 143   if (argc > 3)
 144      burn = atoll(argv[3]);
 145
 146   if (argc > 4)
 147      threads_spec = argv[4];
 148   else
 149      threads_spec = "BSBSBSBS";
 150
 151   fprintf(stderr, "loops/sleep_ms/burn/threads_spec:  %d %d %d %s\n",
 152           loops, sleepms, burn, threads_spec);
 153   fflush(stderr);
 154
 155   b.name = "Brussels";
 156   b.burn = *threads_spec++ == 'B';
 157   b.sleep = *threads_spec++ == 'S';
 158   b.t = -1;
 159   if (b.burn || b.sleep) {
 160      b.t = 1;
 161      pthread_create(&ebbr, NULL, sleeper_or_burner, &b);
 162      wait_ready();
 163   }
 164
 165   l.name = "London";
 166   l.burn = *threads_spec++ == 'B';
 167   l.sleep = *threads_spec++ == 'S';
 168   l.t = -1;
 169   if (l.burn || l.sleep) {
 170      l.t = 2;
 171      pthread_create(&egll, NULL, sleeper_or_burner, &l);
 172      wait_ready();
 173   }
 174
 175   p.name = "Petaouchnok";
 176   p.burn = *threads_spec++ == 'B';
 177   p.sleep = *threads_spec++ == 'S';
 178   p.t = -1;
 179   if (p.burn || p.sleep) {
 180      p.t = 3;
 181      pthread_create(&zzzz, NULL, sleeper_or_burner, &p);
 182      wait_ready();
 183   }
 184
 185   m.name = "main";
 186   m.burn = *threads_spec++ == 'B';
 187   m.sleep = *threads_spec++ == 'S';
 188   m.t = 0;
 189   sleeper_or_burner(&m);
 190
 191   if (b.t != -1) pthread_join(ebbr, NULL);
 192   if (l.t != -1) pthread_join(egll, NULL);
 193   if (p.t != -1) pthread_join(zzzz, NULL);
 194
 195   return 0;
 196 }