ZwQueryInformationThread(ThreadAmILastThread)

//http://waleedassar.blogspot.com
//http://www.twitter.com/waleedassar
//You can use this system call to determine if the running thread is the only thread in the current
// or remote process.
//I found the parameter being called "ThreadAmILastThread", but i prefer to call it "ThreadAmIOnlyThread"
//since the function call returns TRUE if the thread is the only thread in its process.
#include "stdafx.h"
#include "windows.h"
#include "stdio.h"


#define ThreadAmILastThread    0xC
#define ThreadAmIOnlyThread    0xC


extern "C"
{
int __stdcall ZwSetInformationThread(HANDLE,unsigned long,unsigned long*,unsigned long);
int __stdcall ZwQueryInformationThread(HANDLE,unsigned long,unsigned long*,unsigned long,unsigned long*);
}


void Wait()
{
    MessageBox(0,"Waliedassar","waliedassar",0);
    //Sleep(INFINITE);
    return;
}



int main()
{
        //You can comment-out the following to see the difference.
    /*unsigned long tid=0;
    HANDLE hT=CreateThread(0,0x1000,(LPTHREAD_START_ROUTINE)(&Wait),0,0,&tid);
    if(hT==0) return 0;
    Sleep(1000);*/
    unsigned long OnlyThread=0;
    int ret=ZwQueryInformationThread(GetCurrentThread(),
        ThreadAmILastThread,(unsigned long*)(&OnlyThread),0x4,0);
    if(ret>=0) printf("Okay\r\n");
    else       printf("Error %x\r\n",ret);
    printf("Only Thread: is %s\r\n",(OnlyThread?"TRUE":"FALSE"));
    return 0;
}