Make Task Manager sort more meaningful

chrome/browser/task_management/sampling/task_manager_impl_unittest.cc

Index: chrome/browser/task_management/sampling/task_manager_impl_unittest.cc
diff --git a/chrome/browser/task_management/sampling/task_manager_impl_unittest.cc b/chrome/browser/task_management/sampling/task_manager_impl_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..59c27f7ddbf0b39c26d34474424e9e8de640f10d
--- /dev/null
+++ b/chrome/browser/task_management/sampling/task_manager_impl_unittest.cc
@@ -0,0 +1,214 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/task_management/providers/task.h"
+#include "chrome/browser/task_management/sampling/task_manager_impl.h"
+#include "chrome/browser/task_management/task_manager_observer.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace task_management {
+
+namespace {
+
+// A Task for unittests, not backed by a real process, that can report any given
+// value.
+class FakeTask : public Task {
+ public:
+  FakeTask(base::ProcessId process_id,
+           Type type,
+           const std::string& title,
+           int tab_id)
+      : Task(base::ASCIIToUTF16(title),
+             "FakeTask",
+             nullptr,
+             base::kNullProcessHandle,
+             process_id),
+        type_(type),
+        parent_(nullptr),
+        tab_id_(tab_id) {
+    TaskManagerImpl::GetInstance()->TaskAdded(this);
+  }
+
+  ~FakeTask() override { TaskManagerImpl::GetInstance()->TaskRemoved(this); }
+
+  Type GetType() const override { return type_; }
+
+  int GetChildProcessUniqueID() const override { return 0; }
+
+  const Task* GetParentTask() const override { return parent_; }
+
+  int GetTabId() const override { return tab_id_; }
+
+  void SetParent(Task* parent) { parent_ = parent; }
+
+ private:
+  Type type_;
+  Task* parent_;
+  int tab_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeTask);
+};
+
+}  // namespace
+
+class TaskManagerImplTest : public testing::Test, public TaskManagerObserver {
+ public:
+  TaskManagerImplTest()
+      : TaskManagerObserver(base::TimeDelta::FromSeconds(1),
+                            REFRESH_TYPE_NONE) {
+    TaskManagerImpl::GetInstance()->AddObserver(this);
+  }
+  ~TaskManagerImplTest() override {
+    tasks_.clear();
+    observed_task_manager()->RemoveObserver(this);
+  }
+
+  FakeTask* AddTask(int pid_offset,
+                    Task::Type type,
+                    const std::string& title,
+                    int tab_id) {
+    // Offset based on the current process id, to avoid collisions with the
+    // browser process task.
+    base::ProcessId process_id = base::GetCurrentProcId() + pid_offset;
+    tasks_.emplace_back(new FakeTask(process_id, type, title, tab_id));
+    return tasks_.back().get();
+  }
+
+  std::string DumpSortedTasks() {
+    std::string result;
+    for (TaskId task_id : observed_task_manager()->GetTaskIdsList()) {
+      result += base::UTF16ToUTF8(observed_task_manager()->GetTitle(task_id));
+      result += "\n";
+    }
+    return result;
+  }
+
+ private:
+  content::TestBrowserThreadBundle thread_bundle_;
+  std::vector<std::unique_ptr<FakeTask>> tasks_;
+  DISALLOW_COPY_AND_ASSIGN(TaskManagerImplTest);
+};
+
+TEST_F(TaskManagerImplTest, SortingTypes) {
+  AddTask(100, Task::GPU, "Gpu Process", -1);
+
+  Task* tab1 = AddTask(200, Task::RENDERER, "Tab One", 10);
+  AddTask(400, Task::EXTENSION, "Extension Subframe: Tab One", 10)
+      ->SetParent(tab1);
+  AddTask(300, Task::RENDERER, "Subframe: Tab One", 10)->SetParent(tab1);
+
+  Task* tab2 =
+      AddTask(200, Task::RENDERER, "Tab Two: sharing process with Tab One", 20);
+
+  AddTask(301, Task::RENDERER, "Subframe: Tab Two", 20)->SetParent(tab2);
+  AddTask(400, Task::EXTENSION, "Extension Subframe: Tab Two", 20)
+      ->SetParent(tab2);
+
+  AddTask(600, Task::ARC, "ARC", -1);
+  AddTask(800, Task::UTILITY, "Utility One", -1);
+  AddTask(700, Task::UTILITY, "Utility Two", -1);
+  AddTask(1000, Task::GUEST, "Guest", 20);
+  AddTask(900, Task::WORKER, "Worker", -1);
+  AddTask(500, Task::ZYGOTE, "Zygote", -1);
+
+  AddTask(300, Task::RENDERER, "Subframe: Tab One (2)", 10)->SetParent(tab1);
+  AddTask(300, Task::RENDERER, "Subframe: Tab One (third)", 10)
+      ->SetParent(tab1);
+  AddTask(300, Task::RENDERER, "Subframe: Tab One (4)", 10)->SetParent(tab1);
+
+  EXPECT_EQ(
+      "Browser\n"
+      "Gpu Process\n"
+      "ARC\n"
+      "Zygote\n"
+      "Utility One\n"
+      "Utility Two\n"
+      "Tab One\n"
+      "Tab Two: sharing process with Tab One\n"
+      "Subframe: Tab One\n"
+      "Subframe: Tab One (2)\n"
+      "Subframe: Tab One (third)\n"
+      "Subframe: Tab One (4)\n"
+      "Extension Subframe: Tab One\n"
+      "Extension Subframe: Tab Two\n"
+      "Subframe: Tab Two\n"
+      "Guest\n"
+      "Worker\n",
+      DumpSortedTasks());
+}
+
+TEST_F(TaskManagerImplTest, SortingCycles) {
+  // Two tabs, with subframes in the other's process. This induces a cycle in
+  // the TaskGroup dependencies, without being a cycle in the Tasks. This can
+  // happen in practice.
+  Task* tab1 = AddTask(200, Task::RENDERER, "Tab 1: Process 200", 10);
+  AddTask(300, Task::RENDERER, "Subframe in Tab 1: Process 300", 10)
+      ->SetParent(tab1);
+  Task* tab2 = AddTask(300, Task::RENDERER, "Tab 2: Process 300", 20);
+  AddTask(200, Task::RENDERER, "Subframe in Tab 2: Process 200", 20)
+      ->SetParent(tab2);
+
+  // Simulated GPU process.
+  AddTask(100, Task::GPU, "Gpu Process", -1);
+
+  // Two subframes that list each other as a parent (a true cycle). This
+  // shouldn't happen in practice, but we want the sorting code to handle it
+  // gracefully.
+  FakeTask* cycle1 = AddTask(501, Task::SANDBOX_HELPER, "Cycle 1", -1);
+  FakeTask* cycle2 = AddTask(500, Task::ARC, "Cycle 2", -1);
+  cycle1->SetParent(cycle2);
+  cycle2->SetParent(cycle1);
+
+  // A cycle where both elements are in the same group.
+  FakeTask* cycle3 = AddTask(600, Task::SANDBOX_HELPER, "Cycle 3", -1);
+  FakeTask* cycle4 = AddTask(600, Task::ARC, "Cycle 4", -1);
+  cycle3->SetParent(cycle4);
+  cycle4->SetParent(cycle3);
+
+  // Tasks listing a cycle as their parent.
+  FakeTask* lollipop5 = AddTask(701, Task::EXTENSION, "Child of Cycle 3", -1);
+  lollipop5->SetParent(cycle3);
+  FakeTask* lollipop6 = AddTask(700, Task::PLUGIN, "Child of Cycle 4", -1);
+  lollipop6->SetParent(cycle4);
+
+  // A task listing itself as parent.
+  FakeTask* self_cycle = AddTask(800, Task::RENDERER, "Self Cycle", 5);
+  self_cycle->SetParent(self_cycle);
+
+  // Add a plugin child to tab1 and tab2.
+  AddTask(900, Task::PLUGIN, "Plugin: Tab 2", 20)->SetParent(tab1);
+  AddTask(901, Task::PLUGIN, "Plugin: Tab 1", 10)->SetParent(tab1);
+
+  // Finish with a normal renderer task.
+  AddTask(903, Task::RENDERER, "Tab: Normal Renderer", 30);
+
+  // Cycles should wind up on the bottom of the list.
+  EXPECT_EQ(
+      "Browser\n"
+      "Gpu Process\n"
+      "Tab 1: Process 200\n"
+      "Subframe in Tab 2: Process 200\n"
+      "Tab 2: Process 300\n"
+      "Subframe in Tab 1: Process 300\n"
+      "Plugin: Tab 1\n"
+      "Plugin: Tab 2\n"
+      "Tab: Normal Renderer\n"
+      "Cycle 2\n"           // ARC
+      "Cycle 1\n"           // Child of 2
+      "Cycle 4\n"           // ARC; task_id > Cycle 2's
+      "Cycle 3\n"           // Same-process child of 4 (SANDBOX_HELPER > ARC)
+      "Child of Cycle 4\n"  // Child of 4
+      "Child of Cycle 3\n"  // Child of 3
+      "Self Cycle\n",       // RENDERER (> ARC)
+      DumpSortedTasks());
+}
+
+}  // namespace task_management