cmSystemTools: Define directory-specific Windows filesystem retry settings

Inspired-by: Ron W Moore <webbtrail@gmail.com>

Source/cmSystemTools.cxx

@@ -749,14 +749,19 @@ std::string cmSystemTools::FileExistsInParentDirectories(
 }
 
 #ifdef _WIN32
-cmSystemTools::WindowsFileRetry cmSystemTools::GetWindowsFileRetry()
+namespace {
+
+struct WindowsFileRetryInit
+{
+  cmSystemTools::WindowsFileRetry Retry;
+  bool Explicit;
+};
+
+WindowsFileRetryInit InitWindowsFileRetry(wchar_t const* const values[2],
+                                          unsigned int const defaults[2])
 {
-  static WindowsFileRetry retry = { 0, 0 };
-  if (!retry.Count) {
   unsigned int data[2] = { 0, 0 };
   HKEY const keys[2] = { HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE };
-    wchar_t const* const values[2] = { L"FilesystemRetryCount",
-                                       L"FilesystemRetryDelay" };
   for (int k = 0; k < 2; ++k) {
     HKEY hKey;
     if (RegOpenKeyExW(keys[k], L"Software\\Kitware\\CMake\\Config", 0,
@@ -773,9 +778,49 @@ cmSystemTools::WindowsFileRetry cmSystemTools::GetWindowsFileRetry()
       RegCloseKey(hKey);
     }
   }
-    retry.Count = data[0] ? data[0] : 5;
-    retry.Delay = data[1] ? data[1] : 500;
+  WindowsFileRetryInit init;
+  init.Explicit = data[0] || data[1];
+  init.Retry.Count = data[0] ? data[0] : defaults[0];
+  init.Retry.Delay = data[1] ? data[1] : defaults[1];
+  return init;
+}
+
+WindowsFileRetryInit InitWindowsFileRetry()
+{
+  static wchar_t const* const values[2] = { L"FilesystemRetryCount",
+                                            L"FilesystemRetryDelay" };
+  static unsigned int const defaults[2] = { 5, 500 };
+  return InitWindowsFileRetry(values, defaults);
+}
+
+WindowsFileRetryInit InitWindowsDirectoryRetry()
+{
+  static wchar_t const* const values[2] = { L"FilesystemDirectoryRetryCount",
+                                            L"FilesystemDirectoryRetryDelay" };
+  static unsigned int const defaults[2] = { 120, 500 };
+  WindowsFileRetryInit dirInit = InitWindowsFileRetry(values, defaults);
+  if (dirInit.Explicit) {
+    return dirInit;
   }
+  WindowsFileRetryInit fileInit = InitWindowsFileRetry();
+  if (fileInit.Explicit) {
+    return fileInit;
+  }
+  return dirInit;
+}
+
+} // end of anonymous namespace
+
+cmSystemTools::WindowsFileRetry cmSystemTools::GetWindowsFileRetry()
+{
+  static WindowsFileRetry retry = InitWindowsFileRetry().Retry;
+  return retry;
+}
+
+cmSystemTools::WindowsFileRetry cmSystemTools::GetWindowsDirectoryRetry()
+{
+  static cmSystemTools::WindowsFileRetry retry =
+    InitWindowsDirectoryRetry().Retry;
   return retry;
 }
 #endif

Source/cmSystemTools.h

@@ -434,6 +434,7 @@ public:
     unsigned int Delay;
   };
   static WindowsFileRetry GetWindowsFileRetry();
+  static WindowsFileRetry GetWindowsDirectoryRetry();
 #endif
 
   /** Get the real path for a given path, removing all symlinks.