Better support for unspecified property value in wxDateProperty and DatePickerCtrl...

[wxWidgets.git] / interface / wx / snglinst.h

diff --git a/interface/wx/snglinst.h b/interface/wx/snglinst.h
index 41e539fde20910ed07d0f75194d28207ac936563..4ea2d84bb9e3adcb5837cbaa06b7d7d208809dc0 100644 (file)
--- a/interface/wx/snglinst.h
+++ b/interface/wx/snglinst.h
@@ -10,14 +10,15 @@
     @class wxSingleInstanceChecker
 
     wxSingleInstanceChecker class allows to check that only a single instance of a
-    program is running. To do it, you should create an object of this class. As
-    long as this object is alive, calls to
-    wxSingleInstanceChecker::IsAnotherRunning from
-    other processes will return @true.
+    program is running.
+
+    To do it, you should create an object of this class. As long as this object
+    is alive, calls to wxSingleInstanceChecker::IsAnotherRunning from other
+    processes will return @true.
 
     As the object should have the life span as big as possible, it makes sense to
-    create it either as a global or in wxApp::OnInit. For
-    example:
+    create it either as a global or in wxApp::OnInit.
+    For example:
 
     @code
     bool MyApp::OnInit()
@@ -47,10 +48,10 @@
     }
     @endcode
 
-    Note using wxGetUserId() to construct the name: this
-    allows different user to run the application concurrently which is usually the
-    intended goal. If you don't use the user name in the wxSingleInstanceChecker
-    name, only one user would be able to run the application at a time.
+    Note using wxGetUserId() to construct the name: this allows different user
+    to run the application concurrently which is usually the intended goal.
+    If you don't use the user name in the wxSingleInstanceChecker name, only
+    one user would be able to run the application at a time.
 
     This class is implemented for Win32 and Unix platforms (supporting @c fcntl()
     system call, but almost all of modern Unix systems do) only.
@@ -62,37 +63,49 @@ class wxSingleInstanceChecker
 {
 public:
     /**
-        Like Create() but without
-        error checking.
+        Default ctor, use Create() after it.
+    */
+    wxSingleInstanceChecker();
+
+    /**
+        Like Create() but without error checking.
     */
     wxSingleInstanceChecker(const wxString& name,
                             const wxString& path = wxEmptyString);
 
     /**
         Destructor frees the associated resources.
-        Note that it is not virtual, this class is not meant to be used polymorphically
+        Note that it is not virtual, this class is not meant to be used polymorphically.
     */
     ~wxSingleInstanceChecker();
 
     /**
         Initialize the object if it had been created using the default constructor.
         Note that you can't call Create() more than once, so calling it if the
-        @ref wxsingleinstancechecker() "non default ctor"
-        had been used is an error.
+        @ref wxSingleInstanceChecker() "non default ctor" had been used is an error.
 
         @param name
-            must be given and be as unique as possible. It is used as the
+            Must be given and be as unique as possible. It is used as the
             mutex name under Win32 and the lock file name under Unix.
-            GetAppName() and wxGetUserId()
-            are commonly used to construct this parameter.
+            GetAppName() and wxGetUserId() are commonly used to construct
+            this parameter.
         @param path
-            is optional and is ignored under Win32 and used as the directory to
-            create the lock file in under Unix (default is
-            wxGetHomeDir())
+            The path is optional and is ignored under Win32 and used as the
+            directory to create the lock file in under Unix
+            (default is wxGetHomeDir()).
 
         @return Returns @false if initialization failed, it doesn't mean that
-                 another instance is running - use  IsAnotherRunning()
-                 to check for it.
+                another instance is running - use  IsAnotherRunning() to check
+                for it.
+
+        @note
+            One of possible reasons while Create may fail on Unix is that the lock
+            file used for checking already exists but was not created by the user.
+            Therefore applications shouldn't treat failure of this function as fatal
+            condition, because doing so would open them to the possibility of a
+            Denial of Service attack. Instead, they should alert the user about
+            the problem and offer to continue execution without checking if
+            another instance is running.
     */
     bool Create(const wxString& name,
                 const wxString& path = wxEmptyString);