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 #include <signal.h>
  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 static void setup_sigusr_handler(void); // sigusr1 and 2 sigaction setup.
  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    int ret;
  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          ret = select (0, NULL, NULL, NULL, &t[s->t]);
  85          /* We only expect a timeout result from the above. */
  86          if (ret != 0)
  87             perror("unexpected result from select");
  88       }
  89       if (burn > 0 && s->burn)
  90          do_burn();
  91    }
  92    if (report_finished) {
  93       fprintf(stderr, "%s finished to sleep and/or burn\n", s->name);
  94       fflush (stderr);
  95    }
  96    return NULL;
  97 }
  98
  99 // wait till a thread signals it is ready
 100 static void wait_ready(void)
 101 {
 102    int rc;
 103    rc = pthread_mutex_lock(&ready_mutex);
 104    if (rc != 0)
 105       fprintf(stderr, "wait_ready lock error %d_n", rc);
 106    while (! thread_ready && rc == 0) {
 107       rc = pthread_cond_wait(&ready, &ready_mutex);
 108       if (rc != 0)
 109          fprintf(stderr, "wait_ready wait error %d_n", rc);
 110    }
 111    thread_ready = 0;
 112    rc = pthread_mutex_unlock(&ready_mutex);
 113    if (rc != 0)
 114       fprintf(stderr, "wait_ready unlock error %d_n", rc);
 115 }
 116
 117 // We will lock ourselves on one single cpu.
 118 // This bypasses the unfairness of the Valgrind scheduler
 119 // when a multi-cpu machine has enough cpu to run all the
 120 // threads wanting to burn cpu.
 121 static void setaffinity(void)
 122 {
 123 #ifdef VGO_linux
 124    cpu_set_t single_cpu;
 125    CPU_ZERO(&single_cpu);
 126    CPU_SET(1, &single_cpu);
 127    (void) sched_setaffinity(0, sizeof(single_cpu), &single_cpu);
 128 #endif
 129    // GDBTD: equivalent for Darwin ?
 130 }
 131
 132 int main (int argc, char *argv[])
 133 {
 134   char *threads_spec;
 135   pthread_t ebbr, egll, zzzz;
 136   struct spec b, l, p, m;
 137   char *some_mem __attribute__((unused)) = malloc(100);
 138   setaffinity();
 139   setup_sigusr_handler();
 140   if (argc > 1)
 141      loops = atoi(argv[1]);
 142
 143   if (argc > 2)
 144      sleepms = atoi(argv[2]);
 145
 146   if (argc > 3)
 147      burn = atoll(argv[3]);
 148
 149   if (argc > 4)
 150      threads_spec = argv[4];
 151   else
 152      threads_spec = "BSBSBSBS";
 153
 154   fprintf(stderr, "loops/sleep_ms/burn/threads_spec:  %d %d %d %s\n",
 155           loops, sleepms, burn, threads_spec);
 156   fflush(stderr);
 157
 158   b.name = "Brussels";
 159   b.burn = *threads_spec++ == 'B';
 160   b.sleep = *threads_spec++ == 'S';
 161   b.t = -1;
 162   if (b.burn || b.sleep) {
 163      b.t = 1;
 164      pthread_create(&ebbr, NULL, sleeper_or_burner, &b);
 165      wait_ready();
 166   }
 167
 168   l.name = "London";
 169   l.burn = *threads_spec++ == 'B';
 170   l.sleep = *threads_spec++ == 'S';
 171   l.t = -1;
 172   if (l.burn || l.sleep) {
 173      l.t = 2;
 174      pthread_create(&egll, NULL, sleeper_or_burner, &l);
 175      wait_ready();
 176   }
 177
 178   p.name = "Petaouchnok";
 179   p.burn = *threads_spec++ == 'B';
 180   p.sleep = *threads_spec++ == 'S';
 181   p.t = -1;
 182   if (p.burn || p.sleep) {
 183      p.t = 3;
 184      pthread_create(&zzzz, NULL, sleeper_or_burner, &p);
 185      wait_ready();
 186   }
 187
 188   m.name = "main";
 189   m.burn = *threads_spec++ == 'B';
 190   m.sleep = *threads_spec++ == 'S';
 191   m.t = 0;
 192   sleeper_or_burner(&m);
 193
 194   if (b.t != -1) pthread_join(ebbr, NULL);
 195   if (l.t != -1) pthread_join(egll, NULL);
 196   if (p.t != -1) pthread_join(zzzz, NULL);
 197
 198   return 0;
 199 }
 200
 201 static int sigusr1_received = 0;
 202 static void sigusr1_handler(int signr)
 203 {
 204    sigusr1_received++;
 205 }
 206 static void setup_sigusr_handler(void)
 207 {
 208    struct sigaction sa;
 209    sa.sa_handler = sigusr1_handler;
 210    sigemptyset(&sa.sa_mask);
 211    sa.sa_flags = 0;
 212
 213    if (sigaction (SIGUSR1, &sa, NULL) != 0)
 214       perror("sigaction SIGUSR1");
 215
 216    sa.sa_handler = SIG_IGN;
 217    if (sigaction (SIGUSR2, &sa, NULL) != 0)
 218       perror("sigaction SIGUSR2");
 219 }
 220