Track history of events in GCTracer.

test/cctest/test-gc-tracer.cc

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <stdlib.h>
+#include <utility>
+
+#include "src/v8.h"
+
+#include "test/cctest/cctest.h"
+
+using namespace v8::internal;
+
+TEST(RingBufferPartialFill) {
+  const size_t max_size = 6;
+  typedef RingBuffer<size_t, max_size>::const_iterator Iter;
+  RingBuffer<size_t, max_size> ring_buffer;
+  CHECK(ring_buffer.empty());
+  CHECK_EQ(ring_buffer.size(), 0);
+  CHECK(ring_buffer.begin() == ring_buffer.end());
+
+  // Fill ring_buffer partially: [0, 1, 2]
+  for (size_t i = 0; i < max_size/2; i++)
+    ring_buffer.push_back(i);
+
+  CHECK(!ring_buffer.empty());
+  CHECK(ring_buffer.size() == max_size/2);
+  CHECK(ring_buffer.begin() != ring_buffer.end());
+
+  // Test forward itartion
+  size_t i = 0;
+  for (Iter iter = ring_buffer.begin(); iter != ring_buffer.end(); ++iter) {
+    CHECK(*iter == i);
+    ++i;
+  }
+  CHECK_EQ(i, 3);  // one past last element.
+
+  // Test backward iteration
+  i = 2;
+  Iter iter = ring_buffer.back();
+  while (true) {
+    CHECK(*iter == i);
+    if (iter == ring_buffer.begin())
+      break;
+    --iter;
+    --i;
+  }
+  CHECK_EQ(i, 0);
+}
+
+
+TEST(RingBufferWrapAround) {
+  const size_t max_size = 6;
+  typedef RingBuffer<size_t, max_size>::const_iterator Iter;
+  RingBuffer<size_t, max_size> ring_buffer;
+
+  // Fill ring_buffer (wrap around): [9, 10, 11, 12, 13, 14]
+  for (size_t i = 0; i < 2 * max_size + 3; i++)
+    ring_buffer.push_back(i);
+
+  CHECK(!ring_buffer.empty());
+  CHECK(ring_buffer.size() == max_size);
+  CHECK(ring_buffer.begin() != ring_buffer.end());
+
+  // Test forward iteration
+  size_t i = 9;
+  for (Iter iter = ring_buffer.begin(); iter != ring_buffer.end(); ++iter) {
+    CHECK(*iter == i);
+    ++i;
+  }
+  CHECK_EQ(i, 15);  // one past last element.
+
+  // Test backward iteration
+  i = 14;
+  Iter iter = ring_buffer.back();
+  while (true) {
+    CHECK(*iter == i);
+    if (iter == ring_buffer.begin())
+      break;
+    --iter;
+    --i;
+  }
+  CHECK_EQ(i, 9);
+}