/// <summary>
/// given that 'eventRecord' is a TraceLogging event (with meta-data 'metaData'), return a eventID that is unique
/// to that provider/opcode/meta-data blob.
/// </summary>
private ushort GetEventIDForTraceLoggingEvent(TraceEventNativeMethods.EVENT_RECORD *eventRecord, TraceEventNativeMethods.EVENT_HEADER_EXTENDED_DATA_ITEM *metaData)
{
Debug.Assert(metaData->ExtType == TraceEventNativeMethods.EVENT_HEADER_EXT_TYPE_EVENT_SCHEMA_TL);
if (m_traceLoggingEventMap == null) // Lazy init.
{
m_traceLoggingEventMap = new Dictionary <ProviderMetaDataKey, ushort>();
m_nextTraceLoggingIDForProvider = new Dictionary <Guid, ushort>();
}
// Check if I am in the table of assigned eventIds for this meta-data- blob
ProviderMetaDataKey key = new ProviderMetaDataKey(&eventRecord->EventHeader.ProviderId, eventRecord->EventHeader.Opcode, (byte *)metaData->DataPtr, metaData->DataSize);
ushort ret;
if (!m_traceLoggingEventMap.TryGetValue(key, out ret))
{
// No then get the next ID for this particular provider (and allocate a new one)
if (!m_nextTraceLoggingIDForProvider.TryGetValue(eventRecord->EventHeader.ProviderId, out ret))
{
ret = 0xFF00; // We arbitrarily pick the 'high end' of the event ID range to stay way from user-allocated IDs. However we also avoid the last 256 ID just in case.
}
--ret;
m_nextTraceLoggingIDForProvider[eventRecord->EventHeader.ProviderId] = ret;
if (ret == 0) // means we wrapped around. We have no more!
{
throw new InvalidOperationException("Error ran out of TraceLogging Event IDs for provider " + eventRecord->EventHeader.ProviderId);
}
// Make a copy of memory the key points at. Thus the table 'owns' the data the keys point at.
// This is reclaimed in 'Dispose'
int copyDataSize = (key.DataSize + 3) & ~3; // round it up to a multiple of 4. CopyBlob requires this.
byte *copy = (byte *)Marshal.AllocHGlobal(copyDataSize + sizeof(Guid));
key.Provider = (Guid *)(copy);
*key.Provider = eventRecord->EventHeader.ProviderId;
copy += sizeof(Guid);
TraceEvent.CopyBlob((IntPtr)key.Data, (IntPtr)copy, copyDataSize);
key.Data = copy;
// Add the new key and eventID to the table.
m_traceLoggingEventMap.Add(key, ret);
}
return(ret);
}