xenadmin/XenAdmin/Controls/ConsolePanel.cs
Gabor Apati-Nagy 92f0499911 CA-149867: Invoke on MainWindow instead of various controls
We observed that some threads can reach deadlock-ish state after they have Invoked into a control's UI thread. When it happens they are all in a waiting for join or in sleep state for very long time, although there should not be any deadlock situations.
It seems this has something to do with multiple parent controls and with which control we invoked on. This should not make a difference, because we have got one UI thread (for MainWindow) they should wait for, but we have seen it does.

The solution that fixed this issue was to invoke on the MainWindow instead of various controls (see a4fe507adf ).

This changeset is changing all our Invokes to invoke into MainWindow
instead of a control itself. (MainWindow's UI thread is the only UI thread
all Control is using in XenCenter)
This changeset should be in place until we have found the root cause or the exact reason for the above.
2015-04-08 15:16:10 +01:00

491 lines
17 KiB
C#

/* Copyright (c) Citrix Systems Inc.
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* materials provided with the distribution.
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using XenAdmin.ConsoleView;
using XenAPI;
using XenAdmin.Core;
using System.Drawing;
namespace XenAdmin.Controls
{
public class ConsolePanel : UserControl
{
private const int MAX_ACTIVE_VM_CONSOLES = 10;
private List<VM> activeVMConsoles;
private Dictionary<VM, VNCView> vncViews;
private Label errorLabel;
private static string CouldNotConnect = Messages.VNC_COULD_NOT_CONNECT_CONSOLE;
private static string CouldNotFindConsole = Messages.VNC_COULD_NOT_FIND_CONSOLES;
public VNCView activeVNCView = null;
private Panel RbacWarningPanel;
private TableLayoutPanel tableLayoutPanel3;
private PictureBox pictureBox2;
private Label lableRbacWarning;
private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
public ConsolePanel()
: base()
{
InitializeComponent();
this.vncViews = new Dictionary<VM, VNCView>();
this.activeVMConsoles = new List<VM>();
this.Dock = DockStyle.Fill;
pictureBox2.Image = SystemIcons.Warning.ToBitmap();
}
public void PauseAllViews()
{
// We're going to pause all of our VNCViews here, as this gets called when the VNC tab is not selected.
// The VNCView deals with undocked cases.
foreach (VNCView vncView in vncViews.Values)
{
vncView.Pause();
}
}
public void ResetAllViews()
{
vncViews.Clear();
}
public void UnpauseActiveView()
{
// We're going to explicitly pause all the consoles
// except the active one, then explicitly unpause the active one.
foreach (VNCView vncView in vncViews.Values)
{
if (vncView != activeVNCView)
vncView.Pause();
}
if (activeVNCView != null)
{
activeVNCView.Unpause();
}
}
/// <summary>
/// Gives focus to the console, as if the user had clicked it.
/// </summary>
internal void FocusActiveView()
{
if (activeVNCView != null)
activeVNCView.FocusConsole();
}
internal void setCurrentSource(VM source)
{
Program.AssertOnEventThread();
// activeVNCView is going to change, so the current activeVNCView will become inactive
// Start a timer for closing the inactive VNC connection after an interval (20 seconds)
StartCloseVNCTimer(activeVNCView);
this.Controls.Clear();
if (source == null)
{
activeVNCView = null;
return;
}
List<Role> allowedRoles = null;
if (RbacDenied(source, out allowedRoles))
{
lableRbacWarning.Text = String.Format(allowedRoles.Count == 1 ? Messages.RBAC_CONSOLE_WARNING_ONE : Messages.RBAC_CONSOLE_WARNING_MANY,
Role.FriendlyCSVRoleList(source.Connection.Session.Roles),
Role.FriendlyCSVRoleList(allowedRoles));
this.Controls.Add(RbacWarningPanel);
if (activeVNCView != null)
this.Controls.Remove(activeVNCView);
return;
}
activeVMConsoles.Remove(source);
activeVMConsoles.Add(source);
StopCloseVncTimer(source);
while (activeVMConsoles.Count > MAX_ACTIVE_VM_CONSOLES)
{
closeVNCForSource(activeVMConsoles[0]);
}
if (vncViews.ContainsKey(source))
{
activeVNCView = vncViews[source];
}
else
{
activeVNCView = new VNCView(source, null, null);
vncViews[source] = activeVNCView;
}
activeVNCView.refreshIsoList();
this.Controls.Add(activeVNCView);
this.ClearErrorMessage();
}
internal void setCurrentSource(Host source)
{
// sanity...
if (source == null)
{
log.Error("null source when attempting to connect to host VNC");
SetErrorMessage(CouldNotConnect);
return;
}
if (source == null)
{
log.Error("No local copy of host information when connecting to host VNC console...");
SetErrorMessage(CouldNotConnect);
return;
}
if (source.resident_VMs == null)
{
log.Error("No dom0 on host when connecting to host VNC console.");
SetErrorMessage(CouldNotConnect);
return;
}
List<XenRef<VM>> controlVMs =
source.resident_VMs.FindAll((Predicate<XenRef<VM>>)delegate(XenRef<VM> vmRef)
{
VM vm = source.Connection.Resolve<VM>(vmRef);
if (vm == null)
{
return false;
}
else
{
return vm.is_control_domain;
}
});
if (controlVMs.Count > 0)
{
VM vm = source.Connection.Resolve<VM>(controlVMs[0]);
if (vm == null)
{
SetErrorMessage(CouldNotFindConsole);
}
else
{
this.setCurrentSource(vm);
}
}
else
{
SetErrorMessage(CouldNotFindConsole);
}
}
public static bool RbacDenied(VM source, out List<Role> AllowedRoles)
{
if (source == null || source.Connection == null || !Helpers.MidnightRideOrGreater(source.Connection))
{
AllowedRoles = null;
return false;
}
else
{
var session = source.Connection.Session;
if (session != null && session.IsLocalSuperuser)
{
AllowedRoles = null;
return false;
}
}
List<Role> allowedRoles = null;
if (source.is_control_domain)
allowedRoles = Role.ValidRoleList("http/connect_console/host_console", source.Connection);
else
allowedRoles = Role.ValidRoleList("http/connect_console", source.Connection);
if (source.Connection.Session.Roles.Find(delegate(Role r) { return allowedRoles.Contains(r); }) != null)
{
AllowedRoles = allowedRoles;
return false;
}
AllowedRoles = allowedRoles;
return true;
}
internal Image Snapshot(VM vm, string elevatedUsername, string elevatedPassword)
{
Program.AssertOffEventThread();
VNCView view = null;
bool useElevatedCredentials = false;
if (!vncViews.ContainsKey(vm))
{
Program.Invoke(Program.MainWindow, delegate
{
// use elevated credentials, if provided, to create a vncView (CA-91132)
useElevatedCredentials = !String.IsNullOrEmpty(elevatedUsername) && !String.IsNullOrEmpty(elevatedPassword);
if (useElevatedCredentials)
view = new VNCView(vm, elevatedUsername, elevatedPassword);
else
{
setCurrentSource(vm);
if (vncViews.ContainsKey(vm))
view = vncViews[vm];
}
});
}
else
{
view = vncViews[vm];
}
if (view == null)
return null;
Image snapshot = view.Snapshot();
// TODO: only pause the view if we're not currently using it.
// view.Pause();
if (useElevatedCredentials)
{
//used the elevated credentials for snapshot, need to close vnc when finished
Program.Invoke(Program.MainWindow, () => view.Dispose());
}
return snapshot;
}
public void closeVNCForSource(VM source)
{
Program.AssertOnEventThread();
if (!vncViews.ContainsKey(source))
return;
VNCView vncView = vncViews[source];
if (!vncView.isDocked)
return;
vncViews.Remove(source);
vncView.Dispose();
if (activeVMConsoles.Contains(source))
activeVMConsoles.Remove(source);
}
public void closeVNCForSource(VM source, bool vncOnly)
{
if (!vncViews.ContainsKey(source) || vncViews[source] == null
|| (vncOnly && !vncViews[source].IsVNC))
return;
closeVNCForSource(source);
}
public bool isVNCPausedForSource(VM source)
{
Program.AssertOnEventThread();
VNCView vncView = null;
if (vncViews.ContainsKey(source))
{
vncView = vncViews[source];
return vncView.isPaused;
}
return false;
}
private void SetErrorMessage(String message)
{
this.errorLabel.Text = message;
this.errorLabel.Visible = true;
this.Controls.Add(this.errorLabel);
this.setCurrentSource((VM)null);
}
private void ClearErrorMessage()
{
this.errorLabel.Text = "";
this.errorLabel.Visible = false;
this.Controls.Remove(this.errorLabel);
}
private void InitializeComponent()
{
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(ConsolePanel));
this.errorLabel = new System.Windows.Forms.Label();
this.RbacWarningPanel = new System.Windows.Forms.Panel();
this.tableLayoutPanel3 = new System.Windows.Forms.TableLayoutPanel();
this.pictureBox2 = new System.Windows.Forms.PictureBox();
this.lableRbacWarning = new System.Windows.Forms.Label();
this.RbacWarningPanel.SuspendLayout();
this.tableLayoutPanel3.SuspendLayout();
((System.ComponentModel.ISupportInitialize)(this.pictureBox2)).BeginInit();
this.SuspendLayout();
//
// errorLabel
//
resources.ApplyResources(this.errorLabel, "errorLabel");
this.errorLabel.Name = "errorLabel";
//
// RbacWarningPanel
//
this.RbacWarningPanel.BackColor = System.Drawing.Color.Transparent;
this.RbacWarningPanel.Controls.Add(this.tableLayoutPanel3);
resources.ApplyResources(this.RbacWarningPanel, "RbacWarningPanel");
this.RbacWarningPanel.Name = "RbacWarningPanel";
//
// tableLayoutPanel3
//
resources.ApplyResources(this.tableLayoutPanel3, "tableLayoutPanel3");
this.tableLayoutPanel3.Controls.Add(this.pictureBox2, 0, 0);
this.tableLayoutPanel3.Controls.Add(this.lableRbacWarning, 1, 0);
this.tableLayoutPanel3.Name = "tableLayoutPanel3";
//
// pictureBox2
//
resources.ApplyResources(this.pictureBox2, "pictureBox2");
this.pictureBox2.Name = "pictureBox2";
this.pictureBox2.TabStop = false;
//
// lableRbacWarning
//
resources.ApplyResources(this.lableRbacWarning, "lableRbacWarning");
this.lableRbacWarning.Name = "lableRbacWarning";
//
// ConsolePanel
//
this.Controls.Add(this.RbacWarningPanel);
this.Name = "ConsolePanel";
resources.ApplyResources(this, "$this");
this.RbacWarningPanel.ResumeLayout(false);
this.tableLayoutPanel3.ResumeLayout(false);
this.tableLayoutPanel3.PerformLayout();
((System.ComponentModel.ISupportInitialize)(this.pictureBox2)).EndInit();
this.ResumeLayout(false);
}
public void SendCAD()
{
if (this.activeVNCView != null)
this.activeVNCView.SendCAD();
}
internal void SwitchIfRequired()
{
if (activeVNCView != null)
activeVNCView.SwitchIfRequired();
}
#region Close VNC connection
private const int CLOSE_VNC_INTERVAL = 20000; //20 milliseconds
private static readonly Dictionary<VM, Timer> CloseVNCTimers = new Dictionary<VM, Timer>();
public void StartCloseVNCTimer(VNCView vncView)
{
if (vncView == null)
return;
// find the <VM, VNCView> pair in vncViews and start timer on the vm
foreach (var kvp in vncViews.Where(kvp => kvp.Value == vncView))
{
StartCloseVNCTimer(kvp.Key);
break;
}
}
private void StartCloseVNCTimer(VM vm)
{
Program.AssertOnEventThread();
if (CloseVNCTimers.ContainsKey(vm) || !vncViews.ContainsKey(vm))
return;
var t = new Timer {Interval = CLOSE_VNC_INTERVAL};
t.Tick += delegate
{
Program.AssertOnEventThread();
try
{
log.DebugFormat("ConsolePanel: closeVNCForSource({0}) in delegate", vm.Name);
closeVNCForSource(vm, true);
}
catch (Exception exception)
{
log.ErrorFormat("ConsolePanel: Exception closing the VNC console for {0}: {1}",
vm.Name, exception.Message);
}
t.Stop();
CloseVNCTimers.Remove(vm);
log.DebugFormat(
"ConsolePanel: CloseVNCTimer({0}): Timer stopped and removed in delegate",
vm.Name);
};
CloseVNCTimers.Add(vm, t);
log.DebugFormat("ConsolePanel: CloseVNCTimer({0}): Start timer (timers count {1})", vm.Name, CloseVNCTimers.Count);
t.Start();
}
private static void StopCloseVncTimer(VM vm)
{
Program.AssertOnEventThread();
if (!CloseVNCTimers.ContainsKey(vm) || CloseVNCTimers[vm] == null)
return;
CloseVNCTimers[vm].Stop();
CloseVNCTimers.Remove(vm);
log.DebugFormat("ConsolePanel: StopCloseVncTimer({0}): Timer stopped and removed", vm.Name);
}
#endregion
}
}