Translating boost::thread->native_handle() to XP ThreadId - winapi

Question

I've managed to get the Windows ThreadId out of the native_handle() from a boost::thread by using GetThreadId(HANDLE). Sadly that call is not available on Windows XP and after searching around I found the solution to offer als fallback support for XP by traversing all thread via Thread32First() and Thread32Next() functions of the WINAPI.
This does work somehow but my problem is I'm currently only able to identify the threads of my process... I don't now how to match the native_handle() / HANDLE from one side with the appropriate THREADENTRY32 from the loop traversal.
THREADENTRY32 te32;
//...
do {
if( te32.th32OwnerProcessID == GetCurrentProcessId() ) {
DWORD threadId = te32.th32ThreadID;
printf( "\n THREAD ID = 0x%08X", te32.th32ThreadID );
}
} while( Thread32Next(hThreadSnap, &te32 ) );
Can anyone help me with that? How do I convert a boost::thread->native_handle() to the ThreadId on WindowsXP?
Thank you very much!

Answer 1

Pass each thread ID in the loop to OpenThread() until you find a matching HANDLE. For example:
HANDLE hBoostThread = ...; // from boost::thread->native_handle()
DWORD dwBoostThreadID = 0;
THREADENTRY32 te32;
//...
do
{
if( te32.th32OwnerProcessID == GetCurrentProcessId() )
{
HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, te32.th32ThreadID);
if (hThread != NULL)
{
if (hThread == hBoostThread)
{
CloseHandle(hThread);
dwBoostThreadID = te32.th32ThreadID;
break;
}
CloseHandle(hThread);
}
}
}
while( Thread32Next(hThreadSnap, &te32 ) );
For good measure, you can wrap this inside a function that you can call whenever GetThreadId() is not natively available so that your code does not need to know the difference, eg:
DWORD WINAPI MyGetThreadId(HANDLE Thread)
{
THREADENTRY32 te32;
HANDLE hThreadSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
if (hThreadSnap == INVALID_HANDLE_VALUE)
return 0;
if (Thread32First(hThreadSnap, &te32))
{
do
{
HANDLE hOpenThread = OpenThread(THREAD_ALL_ACCESS, FALSE, te32.th32ThreadID);
if (hOpenThread != NULL)
{
if (hOpenThread == Thread)
{
CloseHandle(hOpenThread);
CloseHandle(hThreadSnap);
return te32.th32ThreadID;
}
CloseHandle(hOpenThread);
}
}
while( Thread32Next(hThreadSnap, &te32 ) );
}
CloseHandle(hThreadSnap);
return 0;
}
typedef DWORD (WINAPI *LPFN_GTID)(HANDLE);
LPFN_GTID lpGetThreadId = (LPFN_GTID) GetProcAddress(GetModuleHandle("kernel32"), "GetThreadId");
if (!lpGetThreadId)
lpGetThreadId = &MyGetThreadId;
DWORD dwThreadID = lpGetThreadId((HANDLE) boost::thread->native_handle());
With that said, a better option is to directly query the target thread itself for its own ID, instead of trying to hunt for it manually:
typedef long (WINAPI *LPFN_NTQIT)(HANDLE thread, int infoclass, void *buf, long size, long *used);
typedef struct _THREAD_BASIC_INFORMATION
{
ULONG ExitStatus;
void* TebBaseAddress;
ULONG UniqueProcessId;
ULONG UniqueThreadId;
ULONG AffinityMask;
ULONG BasePriority;
ULONG DiffProcessPriority;
} THREAD_BASIC_INFORMATION;
DWORD WINAPI MyGetThreadId(HANDLE Thread)
{
DWORD dwThreadId = 0;
HMODULE hLib = LoadLibrary("ntdll.dll");
if (hLib != NULL)
{
LPFN_NTQIT lpNtQueryInformationThread = (LPFN_NTQIT) GetProcAddress(hLib, "NtQueryInformationThread");
if (lpNtQueryInformationThread != NULL)
{
THREAD_BASIC_INFORMATION tbi = {0};
ULONG used = 0;
if (lpNtQueryInformationThread(Thread, 0, &tbi, sizeof(tbi), &used) == 0)
dwThreadId = tbi.UniqueThreadId;
}
FreeLibrary(hLib);
}
return dwThreadId;
}