ShowThreadNames tool to get thread ID/name pairs in a Chrome process

tools/win/ShowThreadNames/ShowThreadNames.cc

Index: tools/win/ShowThreadNames/ShowThreadNames.cc
diff --git a/tools/win/ShowThreadNames/ShowThreadNames.cc b/tools/win/ShowThreadNames/ShowThreadNames.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1627ede5800d8a7e9ee8cce50e73c8be735347ab
--- /dev/null
+++ b/tools/win/ShowThreadNames/ShowThreadNames.cc
@@ -0,0 +1,109 @@
+// Copyright (c) 2017 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 <windows.h>
+
+#include <stdio.h>
+#include <tchar.h>
+#include <tlhelp32.h>
+
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <map>
+#include <sstream>
+#include <string>
+
+// List all thread names in a process specified.
+BOOL ListProcessThreadNames(DWORD dwOwnerPID);
+
+// The GetThreadDescription API is available since Windows 10, version 1607.
+// The reason why this API is binded in this way rather than just using the
+// Windows SDK, is to make it consistent with the bind of SetThreadDescription
+// in Chrome. Binding SetThreadDescription API in Chrome can only be done via

[stanisc, 2017/02/23 19:19:44]

You could just say that this API isn't yet available in the SDK that Chrome
builds with.

[chengx, 2017/02/23 20:45:06]

Done.

+// the system dll, rather than SDK.
+typedef HRESULT(WINAPI* GETTHREADDESCRIPTION)(HANDLE hThread,
+                                              PWSTR* threadDescription);
+
+int main(void) {
+  unsigned int processId;
+  std::string user_input;
+  while (true) {
+    std::cout
+        << "\nPlease enter the process Id, or \"quit\" to end the program : ";
+    std::getline(std::cin, user_input);
+    std::cout << std::endl;
+    if (user_input == "quit")
+      break;
+    std::stringstream ss(user_input);
+    if (ss >> processId) {
+      ListProcessThreadNames(processId);
+    } else {
+      std::cout << "input is invalid" << std::endl;
+    }
+    std::cout << std::endl;
+  }
+  return 0;
+}
+
+BOOL ListProcessThreadNames(DWORD dwOwnerPID) {
+  auto get_thread_description_func =
+      reinterpret_cast<GETTHREADDESCRIPTION>(::GetProcAddress(
+          ::GetModuleHandle(L"Kernel32.dll"), "GetThreadDescription"));
+
+  if (!get_thread_description_func) {
+    std::cout << "GetThreadDescription API is not available in current OS"
+              << std::endl;
+    return (FALSE);
+  }
+
+  HANDLE threadSnap = INVALID_HANDLE_VALUE;

[stanisc, 2017/02/23 19:19:44]

How about thread_snapshot?

[chengx, 2017/02/23 20:45:06]

Done.

+  // Take a snapshot of all running threads.
+  threadSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
+  if (threadSnap == INVALID_HANDLE_VALUE)
+    return (FALSE);
+
+  THREADENTRY32 te32;
+  te32.dwSize = sizeof(THREADENTRY32);
+
+  // Retrieve information about the first thread, and exit if unsuccessful.
+  if (!Thread32First(threadSnap, &te32)) {
+    std::cout << "Thread32First() call failed" << std::endl;
+    CloseHandle(threadSnap);
+    return (FALSE);
+  }
+
+  // Walk the thread list of the system, and display ID and name about each
+  // thread associated with the process specified.
+  std::cout << "thread_ID   thread_name" << std::endl;
+  std::multimap<std::wstring, DWORD> name_id_map;
+  do {
+    if (te32.th32OwnerProcessID == dwOwnerPID) {

[stanisc, 2017/02/23 19:19:44]

Use chrome code naming convention for this as well (e.g. owner_pid)

[chengx, 2017/02/23 20:45:06]

Done.

+      HANDLE threadHandle =
+          OpenThread(THREAD_QUERY_INFORMATION, FALSE, te32.th32ThreadID);
+      if (threadHandle) {
+        PWSTR data;
+        HRESULT hr = get_thread_description_func(threadHandle, &data);
+        if (SUCCEEDED(hr)) {
+          std::wstring data_w(data);

[stanisc, 2017/02/23 19:19:44]

Could you use a more descriptive name such as thread_name or thread_description?
Also there is no need to use _w suffix.

[chengx, 2017/02/23 20:45:06]

Done.

+          name_id_map.insert(std::make_pair(data_w, te32.th32ThreadID));
+        } else {
+          std::cout << "GetThreadDescription API call failed" << std::endl;
+        }
+        CloseHandle(threadHandle);
+      }
+    }
+  } while (Thread32Next(threadSnap, &te32));
+
+  // Clean up the snapshot object.
+  CloseHandle(threadSnap);
+
+  // Show all thread ID/name pairs.
+  for (auto it = name_id_map.begin(); it != name_id_map.end(); ++it) {

[stanisc, 2017/02/23 19:19:44]

Nit: you could use C++ 11 foreach loop here - for (auto it : name_id_map)

[chengx, 2017/02/23 20:45:06]

Done.

+    std::cout << it->second << "\t";
+    std::wcout << it->first << std::endl;
+  }
+
+  return (TRUE);
+}