initial custom action library, "hello, world" quality

src/installer-ca/dutil/proc2utl.cpp

+//-------------------------------------------------------------------------------------------------
+// <copyright file="proc2utl.cpp" company="Outercurve Foundation">
+//   Copyright (c) 2004, Outercurve Foundation.
+//   This software is released under Microsoft Reciprocal License (MS-RL).
+//   The license and further copyright text can be found in the file
+//   LICENSE.TXT at the root directory of the distribution.
+// </copyright>
+// 
+// <summary>
+//    Process helper functions that require PSAPI.DLL.
+// </summary>
+//-------------------------------------------------------------------------------------------------
+
+#include "../precomp.h"
+
+/********************************************************************
+ ProcFindAllIdsFromExeName() - returns an array of process ids that are running specified executable.
+
+*******************************************************************/
+extern "C" HRESULT DAPI ProcFindAllIdsFromExeName(
+    __in_z LPCWSTR wzExeName,
+    __out DWORD** ppdwProcessIds,
+    __out DWORD* pcProcessIds
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD er = ERROR_SUCCESS;
+    HANDLE hSnap = INVALID_HANDLE_VALUE;
+    BOOL fContinue = FALSE;
+    PROCESSENTRY32W peData = { sizeof(peData) };
+    
+    hSnap = ::CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+    if (INVALID_HANDLE_VALUE == hSnap)
+    {
+        ExitWithLastError(hr, "Failed to create snapshot of processes on system");
+    }
+
+    fContinue = ::Process32FirstW(hSnap, &peData);
+
+    while (fContinue)
+    {
+        if (0 == lstrcmpiW((LPCWSTR)&(peData.szExeFile), wzExeName))
+        {
+            if (!*ppdwProcessIds)
+            {
+                *ppdwProcessIds = static_cast<DWORD*>(MemAlloc(sizeof(DWORD), TRUE));
+                ExitOnNull(ppdwProcessIds, hr, E_OUTOFMEMORY, "Failed to allocate array for returned process IDs.");
+            }
+            else
+            {
+                DWORD* pdwReAllocReturnedPids = NULL;
+                pdwReAllocReturnedPids = static_cast<DWORD*>(MemReAlloc(*ppdwProcessIds, sizeof(DWORD) * ((*pcProcessIds) + 1), TRUE));
+                ExitOnNull(pdwReAllocReturnedPids, hr, E_OUTOFMEMORY, "Failed to re-allocate array for returned process IDs.");
+
+                *ppdwProcessIds = pdwReAllocReturnedPids;
+            }
+            
+            (*ppdwProcessIds)[*pcProcessIds] = peData.th32ProcessID;
+            ++(*pcProcessIds);
+        }
+
+        fContinue = ::Process32NextW(hSnap, &peData);
+    }
+
+    er = ::GetLastError();
+    if (ERROR_NO_MORE_FILES == er)
+    {
+        hr = S_OK;
+    }
+    else
+    {
+        hr = HRESULT_FROM_WIN32(er);
+    }
+
+LExit:
+    ReleaseFile(hSnap);
+
+    return hr;
+}