Implement a heap profiler for the Dart managed heap.

runtime/vm/heap_profiler_test.cc

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include <arpa/inet.h>
+#include <sys/time.h>
+
+
+#include "vm/heap_profiler.h"
+#include "vm/growable_array.h"
+#include "vm/unit_test.h"
+
+namespace dart {
+
+static void WriteCallback(const void* data, intptr_t length, void* stream) {
+  GrowableArray<uint8_t>* array =
+      reinterpret_cast<GrowableArray<uint8_t>*>(stream);
+  for (intptr_t i = 0; i < length; ++i) {
+    array->Add(reinterpret_cast<const uint8_t*>(data)[i]);
+  }
+}
+
+
+static uint8_t Read8(GrowableArray<uint8_t>* array, intptr_t* i) {
+  EXPECT(array != NULL);
+  EXPECT(i != NULL);
+  EXPECT_LE(*i + 1, array->length());
+  return (*array)[(*i)++];
+}
+
+
+static uint32_t Read32(GrowableArray<uint8_t>* array, intptr_t* i) {
+  EXPECT(array != NULL);
+  EXPECT(i != NULL);
+  EXPECT_LE(*i + 4, array->length());
+  uint32_t result = 0;
+  result |= ((*array)[(*i)++] <<  0);
+  result |= ((*array)[(*i)++] <<  8);
+  result |= ((*array)[(*i)++] << 16);
+  result |= ((*array)[(*i)++] << 24);
+  return ntohl(result);
+}
+
+
+static bool IsTagValid(uint8_t tag) {
+  switch (static_cast<HeapProfiler::Tag>(tag)) {
+    case HeapProfiler::kStringInUtf8:
+    case HeapProfiler::kLoadClass:
+    case HeapProfiler::kUnloadClass:
+    case HeapProfiler::kStackFrame:
+    case HeapProfiler::kStackTrace:
+    case HeapProfiler::kAllocSites:
+    case HeapProfiler::kHeapSummary:
+    case HeapProfiler::kStartThread:
+    case HeapProfiler::kEndThread:
+    case HeapProfiler::kHeapDump:
+    case HeapProfiler::kCpuSamples:
+    case HeapProfiler::kControlSettings:
+    case HeapProfiler::kHeapDumpSummary:
+    case HeapProfiler::kHeapDumpEnd:
+      return true;
+    default:
+      return false;
+  }
+}
+
+
+// Write an empty profile.  Validate the presence of a header and a
+// minimal set of records.
+TEST_CASE(HeapProfileEmpty) {
+  uint64_t before = OS::GetCurrentTimeMillis();
+  GrowableArray<uint8_t> array;
+  {
+    HeapProfiler(WriteCallback, &array);
+  }
+  uint64_t after = OS::GetCurrentTimeMillis();
+  intptr_t i = 0;
+  EXPECT_LE(i + 19, array.length());
+  EXPECT_EQ('J', array[i++]);
+  EXPECT_EQ('A', array[i++]);
+  EXPECT_EQ('V', array[i++]);
+  EXPECT_EQ('A', array[i++]);
+  EXPECT_EQ(' ', array[i++]);
+  EXPECT_EQ('P', array[i++]);
+  EXPECT_EQ('R', array[i++]);
+  EXPECT_EQ('O', array[i++]);
+  EXPECT_EQ('F', array[i++]);
+  EXPECT_EQ('I', array[i++]);
+  EXPECT_EQ('L', array[i++]);
+  EXPECT_EQ('E', array[i++]);
+  EXPECT_EQ(' ', array[i++]);
+  EXPECT_EQ('1', array[i++]);
+  EXPECT_EQ('.', array[i++]);
+  EXPECT_EQ('0', array[i++]);
+  EXPECT_EQ('.', array[i++]);
+  EXPECT_EQ('1', array[i++]);
+  EXPECT_EQ('\0', array[i++]);
+  uint32_t size = Read32(&array, &i);
+  EXPECT_EQ(size, sizeof(void*));  // NOLINT
+  uint64_t hi = Read32(&array, &i);
+  uint64_t lo = Read32(&array, &i);
+  uint64_t time = (hi << 32) | lo;
+  EXPECT_GE(before, time);
+  EXPECT_LE(after, time);
+  while (i != array.length()) {
+    // Check tag
+    uint8_t tag = Read8(&array, &i);
+    EXPECT(IsTagValid(tag));
+    // Check time diff
+    uint32_t time_diff = Read32(&array, &i);
+    EXPECT_LE(before, time + time_diff);
+    EXPECT_GE(after, time + time_diff);
+    // Check length diff
+    uint32_t length = Read32(&array, &i);
+    EXPECT_LE((intptr_t)length + i , array.length());
+    // skip body
+    i += length;
+  }
+}
+
+}  // namespace dart