Question

How can I enumerate all of the threads in a process given a HANDLE to the process (or a process ID)? I’m interested in doing this so I can further do an EnumThreadWindows on each thread.

Answer 1

Enumerating threads in a process at MSDN Blogs.

Code snippet from there:

#include <stdio.h>
#include <windows.h>
#include <tlhelp32.h>

int __cdecl main(int argc, char **argv)
{
 HANDLE h = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
 if (h != INVALID_HANDLE_VALUE) {
  THREADENTRY32 te;
  te.dwSize = sizeof(te);
  if (Thread32First(h, &te)) {
   do {
     if (te.dwSize >= FIELD_OFFSET(THREADENTRY32, th32OwnerProcessID) +
                      sizeof(te.th32OwnerProcessID)) {
       printf("Process 0x%04x Thread 0x%04x\n",
             te.th32OwnerProcessID, te.th32ThreadID);
     }
   te.dwSize = sizeof(te);
   } while (Thread32Next(h, &te));
  }
  CloseHandle(h);
 }
 return 0;
}