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

tools/win/ShowThreadNames/ShowThreadNames.cc

+// 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);
+// Print the error message.
+void printError(TCHAR* msg);
+
+// 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

[brucedawson, 2017/02/23 19:33:11]

binded -> bound

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

Done.

+// Windows SDK, is to make it consistent with the bind of SetThreadDescription
+// in Chrome. Binding SetThreadDescription API in Chrome can only be done via
+// the system dll, rather than SDK.

[brucedawson, 2017/02/23 19:33:12]

"can only be done by GetProcAddress, rather than the import library."

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

Done.

+typedef HRESULT(WINAPI* GETTHREADDESCRIPTION)(HANDLE hThread,
+                                              PWSTR* threadDescription);
+
+int main(void) {
+  unsigned int processId;

[brucedawson, 2017/02/23 19:33:11]

Should use DWORD as type for consistency.

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

Done.

+  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);
+    if (user_input == "quit")
+      break;
+    std::cout << std::endl;
+    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) {
+    printError(TEXT("GetThreadDescription"));
+    return (FALSE);
+  }
+
+  HANDLE threadSnap = INVALID_HANDLE_VALUE;
+  // Take a snapshot of all running threads.
+  threadSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
+  if (threadSnap == INVALID_HANDLE_VALUE) {
+    printError(TEXT("CreateToolhelp32Snapshot"));
+    return (FALSE);
+  }
+
+  THREADENTRY32 te32;
+  te32.dwSize = sizeof(THREADENTRY32);
+
+  // Retrieve information about the first thread, and exit if unsuccessful.
+  if (!Thread32First(threadSnap, &te32)) {
+    printError(TEXT("Thread32First"));
+    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) {
+      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);
+          name_id_map.insert(std::make_pair(data_w, te32.th32ThreadID));

[brucedawson, 2017/02/23 19:33:11]

Don't forget to free the text with LocalFree, per the documentation.

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

Done.

+        } else {
+          printError(TEXT("GetThreadDescription"));
+        }
+        CloseHandle(threadHandle);
+      } else {
+        printError(TEXT("OpenThread"));
+      }
+    }
+  } 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) {
+    std::cout << it->second << "\t";
+    std::wcout << it->first << std::endl;
+  }
+
+  return (TRUE);
+}
+
+void printError(TCHAR* msg) {
+  DWORD eNum;
+  TCHAR sysMsg[256];
+  TCHAR* p;
+
+  eNum = GetLastError();
+  FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+                NULL, eNum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), sysMsg,
+                256, NULL);
+
+  // Trim the end of the line and terminate it with a null.
+  p = sysMsg;
+  while ((*p > 31) || (*p == 9))
+    ++p;
+  do {
+    *p-- = 0;
+  } while ((p >= sysMsg) && ((*p == '.') || (*p < 33)));
+
+  // Display the message.
+  _tprintf(TEXT("\n  WARNING: %s failed with error %d (%s)"), msg, eNum,
+           sysMsg);
+}

[brucedawson, 2017/02/23 19:37:32]

Put a line terminator on the last line.

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

Done.