[UTILMAN] Small refactor on process management code (#2375)

Implement a small helper, GetProcessID(), that will be used to return the process ID which we are interested in. This largely removes some duplicated code. The following patch addresses the Jansen's comment on #1608 PR.

base/applications/utilman/precomp.h

@@ -59,6 +59,7 @@ INT ListBoxRefreshContents(VOID);
 VOID CheckUtilityState(BOOL bUtilState);
 
 /* process.c */
+DWORD GetProcessID(IN LPCWSTR lpProcessName);
 BOOL IsProcessRunning(IN LPCWSTR lpProcessName);
 BOOL LaunchProcess(LPCWSTR lpProcessName);
 BOOL CloseProcess(IN LPCWSTR lpProcessName);

base/applications/utilman/process.c

@@ -12,29 +12,28 @@
 /* FUNCTIONS ******************************************************************/
 
 /**
- * @IsProcessRunning
+ * @GetProcessID
  *
- * Checks if a process is running.
+ * Returns the process executable ID based on the given executable name.
  *
- * @param[in]   ProcName
+ * @param[in]   lpProcessName
  *     The name of the executable process.
  *
  * @return
- *     Returns TRUE if the given process' name is running,
- *     FALSE otherwise.
+ *      Returns the ID number of the process, otherwise 0.
  *
  */
-BOOL IsProcessRunning(IN LPCWSTR lpProcessName)
+DWORD GetProcessID(IN LPCWSTR lpProcessName)
 {
-    BOOL bIsRunning = FALSE;
-    PROCESSENTRY32W Process = {0};
+    PROCESSENTRY32W Process;
 
-    /* Create a snapshot and check whether the given process' executable name is running */
+    /* Create a snapshot and check if the given process name matches with the one from the process entry structure */
     HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
 
     if (hSnapshot == INVALID_HANDLE_VALUE)
-        return FALSE;
+        return 0;
 
+    /* Get the whole size of the structure */
     Process.dwSize = sizeof(Process);
 
     /* Enumerate the processes */
@@ -44,17 +43,62 @@ BOOL IsProcessRunning(IN LPCWSTR lpProcessName)
         {
             if (_wcsicmp(Process.szExeFile, lpProcessName) == 0)
             {
-                /* The process we are searching for is running */
-                bIsRunning = TRUE;
-                break;
+                /* The names match, return the process ID we're interested */
+                CloseHandle(hSnapshot);
+                return Process.th32ProcessID;
             }
         }
         while (Process32NextW(hSnapshot, &Process));
     }
 
-    /* Free the handle and return */
     CloseHandle(hSnapshot);
-    return bIsRunning;
+    return 0;
+}
+
+/**
+ * @IsProcessRunning
+ *
+ * Checks if a process is running.
+ *
+ * @param[in]   lpProcessName
+ *     The name of the executable process.
+ *
+ * @return
+ *     Returns TRUE if the given process' name is running,
+ *     FALSE otherwise.
+ *
+ */
+BOOL IsProcessRunning(IN LPCWSTR lpProcessName)
+{
+    DWORD dwReturn, dwProcessID;
+    HANDLE hProcess;
+
+    /* Get the process ID */
+    dwProcessID = GetProcessID(lpProcessName);
+    if (dwProcessID == 0)
+    {
+        return FALSE;
+    }
+
+    /* Synchronize the process to get its signaling state */
+    hProcess = OpenProcess(SYNCHRONIZE, FALSE, dwProcessID);
+    if (!hProcess)
+    {
+        DPRINT("IsProcessRunning(): Failed to open the process! (Error: %lu)", GetLastError());
+        return FALSE;
+    }
+
+    /* Wait for the process */
+    dwReturn = WaitForSingleObject(hProcess, 0);
+    if (dwReturn == WAIT_TIMEOUT)
+    {
+        /* The process is still running */
+        CloseHandle(hProcess);
+        return TRUE;
+    }
+
+    CloseHandle(hProcess);
+    return FALSE;
 }
 
 /**
@@ -147,43 +191,32 @@ BOOL LaunchProcess(LPCWSTR lpProcessName)
  */
 BOOL CloseProcess(IN LPCWSTR lpProcessName)
 {
-    BOOL bSuccess = FALSE;
-    PROCESSENTRY32W Process = {0};
+    HANDLE hProcess;
+    DWORD dwProcessID;
 
-    /* Create a snapshot and check if the given process' executable name is running */
-    HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
-
-    if (hSnapshot == INVALID_HANDLE_VALUE)
-        return FALSE;
-
-    Process.dwSize = sizeof(Process);
-
-    /* Enumerate the processes */
-    if (Process32FirstW(hSnapshot, &Process))
+    /* Get the process ID */
+    dwProcessID = GetProcessID(lpProcessName);
+    if (dwProcessID == 0)
     {
-        do
-        {
-            if (_wcsicmp(Process.szExeFile, lpProcessName) == 0)
-            {
-                /*
-                 * We have found the process. However we must make
-                 * sure that we DO NOT kill ourselves (the process ID
-                 * matching with the current parent process ID).
-                 */
-                HANDLE hProcess = OpenProcess(PROCESS_TERMINATE, 0, Process.th32ProcessID);
-                if ((hProcess != NULL) && (Process.th32ProcessID != GetCurrentProcessId()))
-                {
-                    TerminateProcess(hProcess, 0);
-                    CloseHandle(hProcess);
-                }
-                bSuccess = TRUE;
-                break;
-            }
-        }
-        while (Process32NextW(hSnapshot, &Process));
+        return FALSE;
     }
 
-    /* Free the handle and return */
-    CloseHandle(hSnapshot);
-    return bSuccess;
+    /* Make sure that the given process ID is not ours, the parent process, so that we do not kill ourselves */
+    if (dwProcessID == GetCurrentProcessId())
+    {
+        return FALSE;
+    }
+
+    /* Open the process so that we can terminate it */
+    hProcess = OpenProcess(PROCESS_TERMINATE, FALSE, dwProcessID);
+    if (!hProcess)
+    {
+        DPRINT("CloseProcess(): Failed to open the process for termination! (Error: %lu)", GetLastError());
+        return FALSE;
+    }
+
+    /* Terminate it */
+    TerminateProcess(hProcess, 0);
+    CloseHandle(hProcess);
+    return TRUE;
 }