tests/test_gc13.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 #include <AD/gc/markswp.h>
  18
  19 #define TRIALS 10000
  20
  21 MarkSweepGC marksweep;
  22
  23 int created = 0;
  24 int destroyed = 0;
  25 int total_created = 0;
  26 int total_destroyed = 0;
  27 int current_trial = 0;
  28 int alive = 0;
  29
  30 class TEST : public GCObject {
  31    int tag;
  32    int junk[30];
  33    int trial;
  34 public:
  35    TEST(int t, int tr) : tag(t), trial(tr)
  36       { for (int i = 0; i < 30; i++) junk[i] = i + tag;
  37         total_created++; created++; }
  38   ~TEST() { total_destroyed++; if (trial == current_trial) destroyed++; }
  39    void trace(GC *) {}
  40    void verify(int t)
  41    {   assert(HM::page_gc(this) == GC::get_default_gc().gc_id());
  42        assert(t == tag);
  43        for (int i = 0; i < 30; i++) assert(junk[i] == i + tag);
  44    }
  45 };
  46
  47 TEST *            ps [TRIALS];
  48 WeakPointer<TEST> wps[TRIALS];
  49
  50 void do_tests(int trial)
  51 {
  52    int i;
  53
  54    cout << "Trial number " << trial << "\n" << flush;
  55
  56    current_trial = trial;
  57
  58    created = 0;
  59    destroyed = 0;
  60
  61    //
  62    // Allocate a bunch of stuff
  63    //
  64    for (i = 0; i < TRIALS; i++)
  65       wps[i] = ps[i] = new TEST(i,trial);
  66
  67    cout << "Data has been allocated\n" << flush;
  68
  69    GC::garbage_collect();
  70
  71    //
  72    // Make sure all the weakpointers are alive even after garbage collection.
  73    //
  74    for (i = 0; i < TRIALS; i++) {
  75       assert (! wps[i].is_null());
  76       wps[i]->verify(i);
  77    }
  78
  79    //
  80    // Delete the non-weak version.
  81    //
  82    for (i = 0; i < TRIALS; i++) {
  83       ps[i] = 0;
  84    }
  85
  86    //
  87    // Check the ones that are still alive
  88    //
  89    for (alive = 0, i = 0; i < TRIALS; i++) {
  90       if (! wps[i].is_null()) {
  91          alive++;
  92          wps[i]->verify(i);
  93       }
  94    }
  95
  96
  97    GC::garbage_collect();
  98
  99    //
 100    // Check the ones that are still alive, again.
 101    //
 102    for (alive = 0, i = 0; i < TRIALS; i++) {
 103       if (! wps[i].is_null()) {
 104          alive++;
 105          wps[i]->verify(i);
 106       }
 107    }
 108
 109    cout << " Created = " << created
 110         << " Destroyed = " << destroyed
 111         << " Alive = " << alive << '\n' << flush;
 112
 113    assert (created == alive + destroyed);
 114
 115    // Make sure at least 80% of all objects are collected.
 116    assert (TRIALS * 8 / 10 <= destroyed);
 117 }
 118
 119 int main()
 120 {
 121    GC::set_default_gc(marksweep);
 122    GC::get_default_gc().set_finalization(true);
 123    cout << "Testing the weak pointers facility\n" << flush;
 124    int trials = 10;
 125    for (int i = 1; i <= trials; i++)
 126      do_tests(i);
 127
 128    cout << " Total created = " << total_created
 129         << " Total destroyed = " << total_destroyed << '\n';
 130
 131    GC::get_default_gc().print_statistics(cout);
 132    cout << "The weakpointers facility seems to be ok\n" << flush;
 133    return 0;
 134 }