suspend threads in the current process

DoSuspendThread.cpp

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

// Pass 0 as the targetProcessId to suspend threads in the current process
void DoSuspendThread(DWORD targetProcessId, DWORD targetThreadId)
{
    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))
                {
                    // Suspend all threads EXCEPT the one we want to keep running
                    if (te.th32ThreadID != targetThreadId && te.th32OwnerProcessID == targetProcessId)
                    {
                        HANDLE thread = ::OpenThread(THREAD_ALL_ACCESS, FALSE, te.th32ThreadID);
                        if (thread != NULL)
                        {
                            SuspendThread(thread);
                            CloseHandle(thread);
                        }
                    }
                }
                te.dwSize = sizeof(te);
            }
            while (Thread32Next(h, &te));
        }
        CloseHandle(h);
    }
}