Refactor ConsoleProcessList (#14421)

This commit is just a slight refactor of `ConsoleProcessList` which I've noticed
was in a poor shape. It replaces iterators with for-range loops, etc.

Additionally this fixes a bug in `SetConsoleWindowOwner`, where it used to
default to the newest client process instead of the oldest.

Finally, it changes the process container type from a doubly linked list
over to a simple array/vector, because using linked lists for heap allocated
elements felt quite a bit silly. To preserve the previous behavior of
`GetProcessList`, it simply iterates through the vector backwards.

* All unit/feature tests pass ✅
* Launching a TUI application inside pwsh inside cmd
  and exiting kills all 3 applications ✅

(cherry picked from commit 391abaf)
Service-Card-Id: 87207823
Service-Version: 1.15

src/host/ft_fuzzer/fuzzmain.cpp

@@ -74,7 +74,6 @@ struct NullDeviceComm : public IDeviceComm
     RETURN_IF_FAILED(gci.ProcessHandleList.AllocProcessData(GetCurrentProcessId(),
                                                             GetCurrentThreadId(),
                                                             0,
-                                                            nullptr,
                                                             &pProcessHandle));
     pProcessHandle->fRootProcess = true;
 

src/host/input.cpp

@@ -274,27 +274,21 @@ void ProcessCtrlEvents()
     const auto LimitingProcessId = gci.LimitingProcessId;
     gci.LimitingProcessId = 0;
 
-    ConsoleProcessTerminationRecord* rgProcessHandleList;
-    size_t cProcessHandleList;
-
-    auto hr = gci.ProcessHandleList
-                  .GetTerminationRecordsByGroupId(LimitingProcessId,
-                                                  WI_IsFlagSet(gci.CtrlFlags,
-                                                               CONSOLE_CTRL_CLOSE_FLAG),
-                                                  &rgProcessHandleList,
-                                                  &cProcessHandleList);
-
-    if (FAILED(hr) || cProcessHandleList == 0)
+    std::vector<ConsoleProcessTerminationRecord> termRecords;
+    const auto hr = gci.ProcessHandleList
+                        .GetTerminationRecordsByGroupId(LimitingProcessId,
+                                                        WI_IsFlagSet(gci.CtrlFlags,
+                                                                     CONSOLE_CTRL_CLOSE_FLAG),
+                                                        termRecords);
+
+    if (FAILED(hr) || termRecords.empty())
     {
         gci.UnlockConsole();
         return;
     }
 
     // Copy ctrl flags.
-    auto CtrlFlags = gci.CtrlFlags;
-    FAIL_FAST_IF(!(!((CtrlFlags & (CONSOLE_CTRL_CLOSE_FLAG | CONSOLE_CTRL_BREAK_FLAG | CONSOLE_CTRL_C_FLAG)) && (CtrlFlags & (CONSOLE_CTRL_LOGOFF_FLAG | CONSOLE_CTRL_SHUTDOWN_FLAG)))));
-
-    gci.CtrlFlags = 0;
+    const auto CtrlFlags = std::exchange(gci.CtrlFlags, 0);
 
     gci.UnlockConsole();
 
@@ -329,10 +323,13 @@ void ProcessCtrlEvents()
     case CONSOLE_CTRL_SHUTDOWN_FLAG:
         EventType = CTRL_SHUTDOWN_EVENT;
         break;
+
+    default:
+        return;
     }
 
     auto Status = STATUS_SUCCESS;
-    for (size_t i = 0; i < cProcessHandleList; i++)
+    for (const auto& r : termRecords)
     {
         /*
          * Status will be non-successful if a process attached to this console
@@ -346,20 +343,13 @@ void ProcessCtrlEvents()
         if (NT_SUCCESS(Status))
         {
             Status = ServiceLocator::LocateConsoleControl()
-                         ->EndTask(rgProcessHandleList[i].dwProcessID,
+                         ->EndTask(r.dwProcessID,
                                    EventType,
                                    CtrlFlags);
-            if (rgProcessHandleList[i].hProcess == nullptr)
+            if (!r.hProcess)
             {
                 Status = STATUS_SUCCESS;
             }
         }
-
-        if (rgProcessHandleList[i].hProcess != nullptr)
-        {
-            CloseHandle(rgProcessHandleList[i].hProcess);
-        }
     }
-
-    delete[] rgProcessHandleList;
 }

src/interactivity/win32/windowio.cpp

@@ -78,7 +78,13 @@ VOID SetConsoleWindowOwner(const HWND hwnd, _Inout_opt_ ConsoleProcessHandle* pP
     else
     {
         // Find a process to own the console window. If there are none then let's use conhost's.
-        pProcessData = gci.ProcessHandleList.GetFirstProcess();
+        pProcessData = gci.ProcessHandleList.GetRootProcess();
+        if (!pProcessData)
+        {
+            // No root process ID? Pick the oldest existing process.
+            pProcessData = gci.ProcessHandleList.GetOldestProcess();
+        }
+
         if (pProcessData != nullptr)
         {
             dwProcessId = pProcessData->dwProcessId;
@@ -988,7 +994,7 @@ LRESULT CALLBACK DialogHookProc(int nCode, WPARAM /*wParam*/, LPARAM lParam)
 NTSTATUS InitWindowsSubsystem(_Out_ HHOOK* phhook)
 {
     auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();
-    auto ProcessData = gci.ProcessHandleList.FindProcessInList(ConsoleProcessList::ROOT_PROCESS_ID);
+    auto ProcessData = gci.ProcessHandleList.GetRootProcess();
     FAIL_FAST_IF(!(ProcessData != nullptr && ProcessData->fRootProcess));
 
     // Create and activate the main window

src/server/ApiDispatchersInternal.cpp

@@ -93,7 +93,6 @@ using Microsoft::Console::Interactivity::ServiceLocator;
             RETURN_IF_FAILED(gci.ProcessHandleList.AllocProcessData(a->ProcessGroupId,
                                                                     0,
                                                                     a->ProcessGroupId,
-                                                                    ProcessHandle,
                                                                     nullptr));
         }
     }

src/server/IoDispatchers.cpp

@@ -435,7 +435,6 @@ PCONSOLE_API_MSG IoDispatchers::ConsoleHandleConnectionRequest(_In_ PCONSOLE_API
     Status = NTSTATUS_FROM_HRESULT(gci.ProcessHandleList.AllocProcessData(dwProcessId,
                                                                           dwThreadId,
                                                                           Cac.ProcessGroupId,
-                                                                          nullptr,
                                                                           &ProcessData));
 
     if (!NT_SUCCESS(Status))

src/server/ProcessHandle.h

@@ -28,6 +28,15 @@ Revision History:
 class ConsoleProcessHandle
 {
 public:
+    ConsoleProcessHandle(const DWORD dwProcessId,
+                         const DWORD dwThreadId,
+                         const ULONG ulProcessGroupId);
+    ~ConsoleProcessHandle() = default;
+    ConsoleProcessHandle(const ConsoleProcessHandle&) = delete;
+    ConsoleProcessHandle(ConsoleProcessHandle&&) = delete;
+    ConsoleProcessHandle& operator=(const ConsoleProcessHandle&) & = delete;
+    ConsoleProcessHandle& operator=(ConsoleProcessHandle&&) & = delete;
+
     const std::unique_ptr<ConsoleWaitQueue> pWaitBlockQueue;
     std::unique_ptr<ConsoleHandleData> pInputHandle;
     std::unique_ptr<ConsoleHandleData> pOutputHandle;
@@ -47,15 +56,6 @@ class ConsoleProcessHandle
     const ULONG64 GetProcessCreationTime() const;
 
 private:
-    ConsoleProcessHandle(const DWORD dwProcessId,
-                         const DWORD dwThreadId,
-                         const ULONG ulProcessGroupId);
-    ~ConsoleProcessHandle() = default;
-    ConsoleProcessHandle(const ConsoleProcessHandle&) = delete;
-    ConsoleProcessHandle(ConsoleProcessHandle&&) = delete;
-    ConsoleProcessHandle& operator=(const ConsoleProcessHandle&) & = delete;
-    ConsoleProcessHandle& operator=(ConsoleProcessHandle&&) & = delete;
-
     ULONG _ulTerminateCount;
     ULONG const _ulProcessGroupId;
     wil::unique_handle const _hProcess;