tests/test_gc6.cc

   1 //////////////////////////////////////////////////////////////////////////////
   2 //  Testing the weak pointers facilities
   3 //  We'll allocate a bunch of dummy objects and store weakpointer referencing
   4 //  them into an array.  The dummy objects are then throw away.
   5 //  We'll test three things:
   6 //     (1) Weakpointers do not prevent objects from being collected.
   7 //     (2) The objects that are still alive is reachable from the
   8 //         weakpointers.
   9 //     (3) The counts add up.
  10 //////////////////////////////////////////////////////////////////////////////
  11
  12 #include <assert.h>
  13 #include <iostream.h>
  14 #include <AD/gc/gcobject.h>
  15 #include <AD/gc/weakptr.h>
  16 #include <AD/gc/gcheaps.h>
  17
  18 #define TRIALS 10000
  19
  20 int created = 0;
  21 int destroyed = 0;
  22 int total_created = 0;
  23 int total_destroyed = 0;
  24 int current_trial = 0;
  25 int alive = 0;
  26
  27 class TEST : public GCObject {
  28    int tag;
  29    int junk[30];
  30    int trial;
  31 public:
  32    TEST(int t, int tr) : tag(t), trial(tr)
  33       { for (int i = 0; i < 30; i++) junk[i] = i + tag;
  34         total_created++; created++; }
  35   ~TEST() { total_destroyed++; if (trial == current_trial) destroyed++; }
  36    void trace(GC *) {}
  37    void verify(int t)
  38    {   assert(HM::page_gc(this) == GC::get_default_gc().gc_id());
  39        assert(t == tag);
  40        for (int i = 0; i < 30; i++) assert(junk[i] == i + tag);
  41    }
  42 };
  43
  44 TEST *            ps [TRIALS];
  45 WeakPointer<TEST> wps[TRIALS];
  46
  47 void do_tests(int trial)
  48 {
  49    int i;
  50
  51    cout << "Trial number " << trial << "\n" << flush;
  52
  53    current_trial = trial;
  54
  55    created = 0;
  56    destroyed = 0;
  57
  58    //
  59    // Allocate a bunch of stuff
  60    //
  61    for (i = 0; i < TRIALS; i++)
  62       wps[i] = ps[i] = new TEST(i,trial);
  63
  64    cout << "Data has been allocated\n" << flush;
  65
  66    GC::garbage_collect();
  67
  68    //
  69    // Make sure all the weakpointers are alive even after garbage collection.
  70    //
  71    for (i = 0; i < TRIALS; i++) {
  72       assert (! wps[i].is_null());
  73       wps[i]->verify(i);
  74    }
  75
  76    //
  77    // Delete the non-weak version.
  78    //
  79    for (i = 0; i < TRIALS; i++) {
  80       ps[i] = 0;
  81    }
  82
  83    //
  84    // Check the ones that are still alive
  85    //
  86    for (alive = 0, i = 0; i < TRIALS; i++) {
  87       if (! wps[i].is_null()) {
  88          alive++;
  89          wps[i]->verify(i);
  90       }
  91    }
  92
  93
  94    GC::garbage_collect();
  95
  96    //
  97    // Check the ones that are still alive, again.
  98    //
  99    for (alive = 0, i = 0; i < TRIALS; i++) {
 100       if (! wps[i].is_null()) {
 101          alive++;
 102          wps[i]->verify(i);
 103       }
 104    }
 105
 106    cout << " Created = " << created
 107         << " Destroyed = " << destroyed
 108         << " Alive = " << alive << '\n' << flush;
 109
 110    assert (created == alive + destroyed);
 111
 112    // Make sure at least 80% of all objects are collected.
 113    assert (TRIALS * 8 / 10 <= destroyed);
 114 }
 115
 116 int main()
 117 {
 118    GC::get_default_gc().set_finalization(true);
 119    cout << "Testing the weak pointers facility\n" << flush;
 120    int trials = 10;
 121    for (int i = 1; i <= trials; i++)
 122      do_tests(i);
 123
 124    cout << " Total created = " << total_created
 125         << " Total destroyed = " << total_destroyed << '\n';
 126
 127    GC::get_default_gc().print_statistics(cout);
 128    cout << "The weakpointers facility seems to be ok\n" << flush;
 129    return 0;
 130 }