delphi – Windows ETW：内核使用者不接收EventCallback或BufferCallback事件

>步骤1：调用OpenTrace,指定在调用ProcessTrace期间将调用的EventCallback和可选BufferCallback函数：

var
    logFile: EVENT_TRACE_LOGFILE;
    currentTrace: TRACEHANDLE;
begin
    ZeroMemory(@logFile, sizeof(logFile));

    logFile.LoggerName := KERNEL_LOGGER_NAME;
    logFile.LogFileName := 'C:\Users\Ian\foo.etl';
    logFile.ProcessTraceMode := 0;
    logFile.EventCallback := RealtimeEventCallback;
    logFile.BufferCallback := BufferCallback; //optional

    currentTrace := OpenTrace(@logFile);
    if (currentTrace = INVALID_PROCESSTRACE_HANDLE) or (currentTrace = -1) then
           RaiseLastWin32Error();

>步骤2：Enable kernel events.这是通过调用StartTrace完成的.在我的情况下,我想跟踪内核interrupts(EVENT_TRACE_FLAG_INTERRUPT)和deferred procedure calls(EVENT_TRACE_FLAG_DPC)：

var
    sessionProperties: PEVENT_TRACE_PROPERTIES;
    bufferSize: Int64;
    th: TRACEHANDLE;
    loggerName: string;
    logFilePath: string;
begin
    loggerName := KERNEL_LOGGER_NAME;
    logFilePath := 'C:\Users\Ian\foo.etl';

    bufferSize := sizeof(EVENT_TRACE_PROPERTIES)
        + 1024 //maximum session name is 1024 characters
        + 1024; //maximum log file name is 1024 characters

    sessionProperties := AllocMem(bufferSize);
    ZeroMemory(sessionProperties, bufferSize);

    sessionProperties.Wnode.BufferSize := bufferSize;
    sessionProperties.Wnode.ClientContext := 1; //QPC clock resolution
    sessionProperties.Wnode.Flags := WNODE_FLAG_TRACED_GUID;
    sessionProperties.Wnode.Guid := SystemTraceControlGuid;
    sessionProperties.EnableFlags := EVENT_TRACE_FLAG_INTERRUPT or EVENT_TRACE_FLAG_DPC;
    sessionProperties.LogFileMode := EVENT_TRACE_FILE_MODE_CIRCULAR;
    sessionProperties.MaximumFileSize := 5;  // 5 MB
    sessionProperties.LoggerNameOffset := sizeof(EVENT_TRACE_PROPERTIES);
    sessionProperties.LogFileNameOffset := sizeof(EVENT_TRACE_PROPERTIES)+1024;

    //Copy LoggerName to the offset address
    MoveMemory(Pointer(Cardinal(sessionProperties)+sessionProperties.LoggerNameOffset), PChar(loggerName), Length(loggerName)+1);

    //Copy LogFilePath to the offset address
    MoveMemory(Pointer(Cardinal(sessionProperties)+sessionProperties.LogFileNameOffset), PChar(logFilePath), Length(logFilePath)+1);

    hr := StartTrace({var}th, PChar(loggerName), sessionProperties);
    if (hr <> ERROR_SUCCESS) then
          raise EWin32Error.Create(SysErrorMessage(hr));

并且日志成功启动(我可以看到foo.etl开始增长到它的5 MB circuluar限制).
>步骤3：调用ProcessTrace,阻止它将所有挂起事件传递给步骤1中指定的EventCallback处理程序：

var
   res: LongWord;
begin
   res := EventTrace.ProcessTrace(@currentTrace, 1, nil, nil);
   if (res <> ERROR_SUCCESS) then
      raise EWin32Error.Create(SysErrorMessage(res));

除了ProcessTrace立即重复返回,并且没有调用回调 – 即使etl文件存在并且正在增长.

如果我将记录从基于文件更改为实时日志记录：

>第1步 – OpenTrace更改以支持实时：

logFile.ProcessTraceMode := PROCESS_TRACE_MODE_REAL_TIME;

>第2步 – StartTrace更改以支持实时：

sessionProperties.LogFileMode := EVENT_TRACE_REAL_TIME_MODE;

在这种情况下,ProcessTrace永远不会返回,但是从未调用过EventCallback或BufferCallback.

我究竟做错了什么？

更新：我的回调函数：

function BufferCallback(Logfile: PEVENT_TRACE_LOGFILE): LongWord; stdcall;
begin
   ShowMessage('BufferCallback');
   Result := 1; //return true to keep processing rows
end;

procedure RealtimeEventCallback(pEvent: PEVENT_TRACE); stdcall;
begin
   ShowMessage('EventCallback');
   nEvents := nEvents+1;
end;

我使用的标题不是四字对齐的.

在Delphi的说法中,正在使用关键字packed.