Change halfway-to-the-max GC trigger to measure committed pages, not allocated objects

test/mjsunit/gc-early-with-fragmentation.js

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 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --max-old-space-size=60 --check-handle-count
+// Test that we don't keep doing new-space scavenges when the fragmented old
+// space should be forcing us to do mark-sweeps.  Passes by not crashing.
 
-table = [];
+// This is a 32bit-only test.  It generates about 20Mbytes of live data.
+// At the time of writing, this test passes with max old space size 40,
+// whereas before it only passed with old space size 70.  Set the limit
+// at 50 in order to run fast, and not be too flaky.  We limit semispace
+// size too, since 50 is very low relative to the default 8Mbyte semispace
+// size.  A separate issue means we don't accellerate incremental marking
+// fast enough when nearing the limit.  We will deal with that in a
+// different change, hence we switch off incremental marking for this test.
 
-for (var i = 0; i < 32; i++) {
- table[i] = String.fromCharCode(i + 0x410);
+// Flags: --max-old-space-size=50 --no-incremental-marking --max-semi-space-size=4
+
+var shortlived = Array(400);
+var longlived = Array(1000);
+for (var i = 0; i < 10000; i++) {
+  if ((i % 100) == 0) print(i);
+  var a = new Array(5000);
+  shortlived[i % 400] = a;
+  longlived[((i / 10) | 0) % 1000] = a;
 }
-
-
-var random = (function() {
-  var seed = 10;
-  return function() {
-    seed = (seed * 1009) % 8831;
-    return seed;
-  };
-})();
-
-
-function key(length) {
-  var s = "";
-  for (var i = 0; i < length; i++) {
-    s += table[random() % 32];
-  }
-  return '"' + s + '"';
-}
-
-
-function value() {
-  return '[{' + '"field1" : ' + random() + ', "field2" : ' + random() + '}]';
-}
-
-
-function generate(n) {
-  var s = '{';
-  for (var i = 0; i < n; i++) {
-     if (i > 0) s += ', ';
-     s += key(random() % 10 + 7);
-     s += ':';
-     s += value();
-  }
-  s += '}';
-  return s;
-}
-
-
-print("generating");
-
-var str = generate(50000);
-
-print("parsing "  + str.length);
-JSON.parse(str);
-
-print("done");