Track live instance and allocation counts for classes

runtime/vm/heap_class_stats.cc

+// Copyright (c) 2013, 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 "platform/assert.h"
+#include "vm/object.h"
+#include "vm/heap_class_stats.h"
+
+namespace dart {
+
+class HeapClassStatsVisitor : public ObjectVisitor {
+ public:
+  explicit HeapClassStatsVisitor(Isolate* isolate) : ObjectVisitor(isolate) { }
+
+  virtual void VisitObject(RawObject* obj) {
+    intptr_t cid = obj->GetClassId();
+    if (!obj->IsHeapObject()) {
+      return;
+    }
+    bool new_space = obj->IsNewObject();
+    HeapClassStatistics* heap_class_stats = isolate()->heap_class_stats();
+    if (new_space) {
+      heap_class_stats->ReportLiveNewSpace(cid);
+    } else {
+      heap_class_stats->ReportLiveOldSpace(cid);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HeapClassStatsVisitor);
+};
+
+
+HeapClassStatistics::HeapClassStatistics(Isolate* isolate) : isolate_(isolate) {
+  class_table_size_ = 512;
+  class_table_ = reinterpret_cast<HeapClassData*>(
+      calloc(class_table_size_, sizeof(HeapClassData)));  // NOLINT
+}
+
+
+HeapClassStatistics::~HeapClassStatistics() {
+  free(class_table_);
+}
+
+
+void HeapClassStatistics::RegisterClass(const Class& cls) {
+  intptr_t cid = cls.id();
+  if (cid < class_table_size_) {
+    // Already have room.
+    return;
+  }
+  // Resize the table.
+  const intptr_t new_class_table_size = class_table_size_ * 2;
+  HeapClassData* new_class_table = reinterpret_cast<HeapClassData*>(
+      realloc(class_table_,
+              new_class_table_size * sizeof(HeapClassData)));  // NOLINT
+  for (intptr_t i = class_table_size_; i < new_class_table_size; i++) {
+    new_class_table[i].live_old_space = 0;
+    new_class_table[i].live_new_space = 0;
+    new_class_table[i].allocated_since_gc = 0;
+  }
+  class_table_ = new_class_table;
+  class_table_size_ = new_class_table_size;
+  ASSERT(cid < class_table_size_);
+}
+
+
+void HeapClassStatistics::AllocateClass(intptr_t cid) {
+  ASSERT(cid < class_table_size_);
+  class_table_[cid].allocated_since_gc++;
+}
+
+
+void HeapClassStatistics::Collect() {
+  HeapClassStatsVisitor visitor(isolate_);
+  // debugging.
+  for (intptr_t i = 0; i < class_table_size_; i++) {
+    break;
+    const HeapClassData& data = class_table_[i];
+    if ((data.live_old_space == 0) && (data.live_new_space == 0) &&
+        (data.allocated_since_gc == 0)) {
+      continue;
+    }
+    printf("%ld %ld %ld %ld\n", i, data.live_old_space, data.live_new_space,
+                                data.allocated_since_gc);
+  }
+  ResetCounters();
+  isolate_->heap()->IterateObjects(&visitor);
+}
+
+
+uword HeapClassStatistics::ClassStatsTableAddress() {
+  return reinterpret_cast<uword>(&class_table_);
+}
+
+
+void HeapClassStatistics::ResetCounters() {
+  for (intptr_t i = 0; i < class_table_size_; i++) {
+    class_table_[i].live_old_space = 0;
+    class_table_[i].live_new_space = 0;
+    class_table_[i].allocated_since_gc = 0;
+  }
+}
+
+
+void HeapClassStatistics::ReportLiveOldSpace(intptr_t cid) {
+  ASSERT(cid < class_table_size_);
+  class_table_[cid].live_old_space++;
+}
+
+
+void HeapClassStatistics::ReportLiveNewSpace(intptr_t cid) {
+  ASSERT(cid < class_table_size_);
+  class_table_[cid].live_new_space++;
+}
+
+}  // namespace dart