public void Start()
{
try
{
m_TraceEventSession = new TraceEventSession(SessionName, null);
m_TraceEventSession.EnableKernelProvider(GetKeyEvents());
m_TraceEventSource = new ETWTraceEventSource(SessionName, TraceEventSourceType.Session);
m_TraceEventSource.Kernel.All += new Action<TraceEvent>(Kernel_All);
Running = true;
}
catch (Exception ex)
{
Stop();
throw;
}
}
/// <summary>
/// Once started, event sessions will persist even after the process that created them dies. They are
/// only stoped by this explicit Stop() API. If you used both kernel and user events, consider
/// using the code:StopUserAndKernelSession API instead.
/// </summary>
public void Stop()
{
if (stopped)
return;
stopped = true;
int hr = TraceEventNativeMethods.ControlTrace(0UL, sessionName,
ToUnmanagedBuffer(properties, null), TraceEventNativeMethods.EVENT_TRACE_CONTROL_STOP);
// TODO enumerate providers in session and turn them off
#if false
string regKeyName = @"Software\Microsoft\Windows\CurrentVersion\Winevt\Publishers\{" + providerGuid + "}";
Microsoft.Win32.RegistryKey regKey = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(regKeyName, true);
regKey.DeleteValue("ControllerData", false);
regKey.Close();
#endif
if (hr != 4201) // Instance name not found. This means we did not start
Marshal.ThrowExceptionForHR(TraceEventNativeMethods.GetHRFromWin32(hr));
if (kernelSession != null)
{
kernelSession.Stop();
kernelSession = null;
}
}
/// <summary>
/// TraceEventSessions may have both a kernel session and a user session turned on. To simplify
/// error handling, call code:StopSession to stop both. This is equivalent it attaching to the
/// combined session and calling Stop, but also works in all error cases (if it was possible to stop
/// the sessions they are stopped), and is silent if the sessions are already stopped.
/// </summary>
/// <param name="userSessionName">The name of the user session to stop</param>
public static void StopUserAndKernelSession(string userSessionName)
{
Exception eToThow = null;
try
{
TraceEventSession kernelSession = new TraceEventSession(KernelTraceEventParser.KernelSessionName);
kernelSession.Stop();
}
catch (COMException e)
{
if ((uint)e.ErrorCode != 0x80071069) // Could not find provider, that is OK.
eToThow = e;
}
catch (Exception e)
{
eToThow = e; // we will throw this later.
}
try
{
TraceEventSession userSession = new TraceEventSession(userSessionName);
userSession.Stop();
}
catch (COMException e)
{
if ((uint)e.ErrorCode != 0x80071069) // Could not find provider, that is OK
throw;
}
// If we got an error closing down the kernel provider, throw it here.
if (eToThow != null)
throw eToThow;
}
/// <summary>
/// #EnableKernelProvider
/// Enable the kernel provider for the session. If the session name is 'NT Kernel Session' then it
/// operates on that. This can be used to manipuate the kernel session. If the name is not 'NT
/// Kernel Session' AND it is a moduleFile based session, then it tries to approximate attaching the
/// kernel session by creating another session logs to [basename].kernel.etl. There is support in
/// ETWTraceEventSource for looking for these files automatically, which give a good illusion that
/// you can have a session that has both kernel and user events turned on.
/// <param name="flags">
/// Specifies the particular kernel events of interest</param>
/// <param name="stackCapture">
/// Specifies which events should have their eventToStack traces captured too (VISTA only)</param>
/// <returns>Returns true if the session had existed before and is now restarted</returns>
/// </summary>
public unsafe bool EnableKernelProvider(KernelTraceEventParser.Keywords flags, KernelTraceEventParser.Keywords stackCapture)
{
if (sessionName != KernelTraceEventParser.KernelSessionName)
{
if (kernelSession != null)
throw new Exception("A kernel session is already active.");
if (string.IsNullOrEmpty(FileName))
throw new Exception("Cannot enable kernel events to a real time session unless it is named " + KernelTraceEventParser.KernelSessionName);
string kernelFileName = System.IO.Path.ChangeExtension(FileName, ".kernel.etl");
kernelSession = new TraceEventSession(KernelTraceEventParser.KernelSessionName, kernelFileName);
return kernelSession.EnableKernelProvider(flags, stackCapture);
}
if (sessionHandle != TraceEventNativeMethods.INVALID_HANDLE_VALUE)
throw new Exception("The kernel provider must be enabled as the only provider.");
properties.Wnode.Guid = KernelTraceEventParser.ProviderGuid;
if (Environment.OSVersion.Version.Major <= 5)
{
// TODO should we fail, or should we silently ignore?
if (stackCapture != KernelTraceEventParser.Keywords.None)
throw new Exception("Stack trace capture only available on Windows 6 (VISTA) and above.");
KernelTraceEventParser.Keywords vistaOnlyFlags =
KernelTraceEventParser.Keywords.ProcessCounters |
KernelTraceEventParser.Keywords.ContextSwitch |
KernelTraceEventParser.Keywords.Interrupt |
KernelTraceEventParser.Keywords.DiskIOInit |
KernelTraceEventParser.Keywords.Driver |
KernelTraceEventParser.Keywords.Profile |
KernelTraceEventParser.Keywords.FileIO |
KernelTraceEventParser.Keywords.FileIOInit |
KernelTraceEventParser.Keywords.Dispatcher |
KernelTraceEventParser.Keywords.VirtualAlloc;
KernelTraceEventParser.Keywords setVistaFlags = flags & vistaOnlyFlags;
if (setVistaFlags != KernelTraceEventParser.Keywords.None)
throw new Exception("A Kernel Event Flags {" + setVistaFlags.ToString() + "} specified that is not supported on Pre-VISTA OSes.");
properties.EnableFlags = (uint) flags;
return StartTrace();
}
// Initialize the stack collecting information
const int stackTracingIdsMax = 96;
int curID = 0;
var stackTracingIds = stackalloc TraceEventNativeMethods.STACK_TRACING_EVENT_ID[stackTracingIdsMax];
#if DEBUG
// Try setting all flags, if we overflow an assert in SetStackTraceIds will fire.
SetStackTraceIds((KernelTraceEventParser.Keywords)(-1), stackTracingIds, stackTracingIdsMax);
#endif
if (stackCapture != KernelTraceEventParser.Keywords.None)
curID = SetStackTraceIds(stackCapture, stackTracingIds, stackTracingIdsMax);
// The Profile event requires the SeSystemProfilePrivilege to succeed, so set it.
if ((flags & KernelTraceEventParser.Keywords.Profile) != 0)
TraceEventNativeMethods.SetSystemProfilePrivilege();
bool ret = false;
properties.EnableFlags = (uint)flags;
int dwErr;
try
{
dwErr = TraceEventNativeMethods.StartKernelTrace(out sessionHandle, ToUnmanagedBuffer(properties, fileName), stackTracingIds, curID);
if (dwErr == 0xB7) // STIERR_HANDLEEXISTS
{
ret = true;
Stop();
Thread.Sleep(100); // Give it some time to stop.
dwErr = TraceEventNativeMethods.StartKernelTrace(out sessionHandle, ToUnmanagedBuffer(properties, fileName), stackTracingIds, curID);
}
}
catch (BadImageFormatException)
{
// We use a small native DLL called KernelTraceControl that needs to be
// in the same directory as the EXE that used TraceEvent.dll. Unlike IL
// Native DLLs are specific to a processor type (32 or 64 bit) so the easiest
// way to insure this is that the EXE that uses TraceEvent is built for 32 bit
// and that you use the 32 bit version of KernelTraceControl.dll
throw new BadImageFormatException("Could not load KernelTraceControl.dll (likely 32-64 bit process mismatch)");
}
catch (DllNotFoundException)
{
// In order to start kernel session, we need a support DLL called KernelTraceControl.dll
// This DLL is available by downloading the XPERF.exe tool (see
// http://msdn.microsoft.com/en-us/performance/cc825801.aspx for instructions)
// It is recommended that you get the 32 bit version of this (it works on 64 bit machines)
// and build your EXE that uses TraceEvent to launch as a 32 bit application (This is
// the default for VS 2010 projects).
throw new DllNotFoundException("KernelTraceControl.dll missing from distribution.");
}
if (dwErr == 5 && Environment.OSVersion.Version.Major > 5) // On Vista and we get a 'Accessed Denied' message
throw new UnauthorizedAccessException("Error Starting ETW: Access Denied (Administrator rights required to start ETW)");
Marshal.ThrowExceptionForHR(TraceEventNativeMethods.GetHRFromWin32(dwErr));
return ret;
}
/// <summary>
/// Open an existing Windows Event Tracing Session, with name 'sessionName'.
///
/// If you are opening a new session use TraceEventSession(string, string).
///
/// To support the illusion that you can have a session with both kernel and user events,
/// TraceEventSession might start up both a kernel and a user session. When you want to 'attach'
/// to such a combined session, the constructor needs to know if you want to control the kernel
/// session or not. If attachKernelSession is true, then it opens both sessions (and thus 'Close'
/// will operation on both sessions.
/// </summary>
public TraceEventSession(string sessionName, bool attachKernelSession)
{
Init(sessionName);
int hr = TraceEventNativeMethods.ControlTrace(0UL, sessionName, ToUnmanagedBuffer(properties, null), TraceEventNativeMethods.EVENT_TRACE_CONTROL_QUERY);
Marshal.ThrowExceptionForHR(TraceEventNativeMethods.GetHRFromWin32(hr));
isActive = true;
properties = (TraceEventNativeMethods.EVENT_TRACE_PROPERTIES)Marshal.PtrToStructure(unmanagedPropertiesBuffer, typeof(TraceEventNativeMethods.EVENT_TRACE_PROPERTIES));
if (properties.LogFileNameOffset != 0)
fileName = Marshal.PtrToStringUni((IntPtr)(unmanagedPropertiesBuffer.ToInt64() + properties.LogFileNameOffset));
if (attachKernelSession)
{
bool success = false;
try
{
kernelSession = new TraceEventSession(KernelTraceEventParser.KernelSessionName);
success = true;
}
finally
{
if (!success)
Stop();
}
}
}
