/// <summary>
/// Helper function for IsDescendantOfProcessHelper().
/// This function prevents an edge case where a process has a parent process ID
/// that refers to a descendant of itself. This can occur when the parent of a process
/// is destroyed and the parent's pid is recycled and reused on a descendant. The
/// parent process ID value is never updated when the parent is destroyed. The solution
/// is to make sure that parents are created before children, otherwise it is a cycle.
/// </summary>
/// <param name="processSearcher">Process searcher object.</param>
/// <param name="descendant">Process ID of the descendant.</param>
/// <param name="anscestor">Process ID of the ancestor.</param>
/// <param name="previousCreationTime">Creation time of the previous call's descendant.</param>
/// <returns>True if descendant is a descendant of ancestor.</returns>
private static bool IsDescendantOfProcessHelper(
ProcessSearcher processSearcher,
uint descendant,
uint anscestor,
DateTime previousCreationTime)
{
List <ProcessInfo> results = processSearcher.GetResultsByID(descendant);
foreach (ProcessInfo proc in results)
{
// Ensure this parent relationship is valid.
if (proc.CreationDate <= previousCreationTime)
{
if (descendant == anscestor)
{
return(true);
}
else if (descendant == proc.ParentID)
{
// If process is its own parent then we have a cycle, return false.
return(false);
}
return(IsDescendantOfProcessHelper(
processSearcher,
proc.ParentID,
anscestor,
proc.CreationDate));
}
}
return(false);
}
/// <summary>
/// Constructs the PluginDebuggerHelper.
/// </summary>
/// <param name="dte">Automation object from Visual Studio.</param>
/// <param name="properties">PropertyManager set to a valid project/platform.</param>
protected PluginDebuggerBase(DTE2 dte, PropertyManager properties)
{
if (dte == null)
{
throw new ArgumentNullException("dte");
}
if (properties == null)
{
throw new ArgumentNullException("properties");
}
Dte = dte;
// Every second, check for a new instance of the plug-in to attach to.
// Note that although the timer itself runs on a separate thread, the event
// is fired from the main UI thread during message processing, thus we do not
// need to worry about threading issues.
pluginFinderTimer_ = new Timer();
pluginFinderTimer_.Tick += new EventHandler(FindAndAttachToPlugin);
pluginFinderForbiddenPids_ = new List <uint>();
processSearcher_ = new ProcessSearcher();
pluginFinderTimer_.Interval = InitialPluginCheckFrequency;
pluginFinderTimer_.Start();
}
/// <summary>
/// Constructs the PluginDebuggerHelper.
/// </summary>
/// <param name="dte">Automation object from Visual Studio.</param>
/// <param name="properties">PropertyManager set to a valid project/platform.</param>
protected PluginDebuggerBase(DTE2 dte, PropertyManager properties)
{
if (dte == null)
{
throw new ArgumentNullException("dte");
}
if (properties == null)
{
throw new ArgumentNullException("properties");
}
Dte = dte;
// Every second, check for a new instance of the plug-in to attach to.
// Note that although the timer itself runs on a separate thread, the event
// is fired from the main UI thread during message processing, thus we do not
// need to worry about threading issues.
pluginFinderTimer_ = new Timer();
pluginFinderTimer_.Tick += new EventHandler(FindAndAttachToPlugin);
pluginFinderForbiddenPids_ = new List<uint>();
processSearcher_ = new ProcessSearcher();
pluginFinderTimer_.Interval = InitialPluginCheckFrequency;
pluginFinderTimer_.Start();
}
/// <summary>
/// This checks if the first argument is a descendant of the second, where
/// both arguments are process IDs of two processes.
/// </summary>
/// <param name="processSearcher">Process searcher object.</param>
/// <param name="descendant">Process ID of the descendant.</param>
/// <param name="ancestor">Process ID of ancestor.</param>
/// <returns>True if descendant is a descendant of ancestor.</returns>
public static bool IsDescendantOfProcess(
ProcessSearcher processSearcher,
uint descendant,
uint ancestor)
{
return(IsDescendantOfProcessHelper(
processSearcher,
descendant,
ancestor,
DateTime.UtcNow));
}
/// <summary>
/// Helper function for IsDescendantOfProcessHelper().
/// This function prevents an edge case where a process has a parent process ID
/// that refers to a descendant of itself. This can occur when the parent of a process
/// is destroyed and the parent's pid is recycled and reused on a descendant. The
/// parent process ID value is never updated when the parent is destroyed. The solution
/// is to make sure that parents are created before children, otherwise it is a cycle.
/// </summary>
/// <param name="processSearcher">Process searcher object.</param>
/// <param name="descendant">Process ID of the descendant.</param>
/// <param name="anscestor">Process ID of the ancestor.</param>
/// <param name="previousCreationTime">Creation time of the previous call's descendant.</param>
/// <returns>True if descendant is a descendant of ancestor.</returns>
private static bool IsDescendantOfProcessHelper(
ProcessSearcher processSearcher,
uint descendant,
uint anscestor,
DateTime previousCreationTime)
{
List<ProcessInfo> results = processSearcher.GetResultsByID(descendant);
foreach (ProcessInfo proc in results)
{
// Ensure this parent relationship is valid.
if (proc.CreationDate <= previousCreationTime)
{
if (descendant == anscestor)
{
return true;
}
else if (descendant == proc.ParentID)
{
// If process is its own parent then we have a cycle, return false.
return false;
}
return IsDescendantOfProcessHelper(
processSearcher,
proc.ParentID,
anscestor,
proc.CreationDate);
}
}
return false;
}
/// <summary>
/// This checks if the first argument is a descendant of the second, where
/// both arguments are process IDs of two processes.
/// </summary>
/// <param name="processSearcher">Process searcher object.</param>
/// <param name="descendant">Process ID of the descendant.</param>
/// <param name="ancestor">Process ID of ancestor.</param>
/// <returns>True if descendant is a descendant of ancestor.</returns>
public static bool IsDescendantOfProcess(
ProcessSearcher processSearcher,
uint descendant,
uint ancestor)
{
return IsDescendantOfProcessHelper(
processSearcher,
descendant,
ancestor,
DateTime.UtcNow);
}
