ExitThread function (processthreadsapi.h)

Ends the calling thread.


void ExitThread(
  [in] DWORD dwExitCode


[in] dwExitCode

The exit code for the thread.

Return value



ExitThread is the preferred method of exiting a thread in C code. However, in C++ code, the thread is exited before any destructors can be called or any other automatic cleanup can be performed. Therefore, in C++ code, you should return from your thread function.

When this function is called (either explicitly or by returning from a thread procedure), the current thread's stack is deallocated, all pending I/O initiated by the thread that is not associated with a completion port is canceled, and the thread terminates. The entry-point function of all attached dynamic-link libraries (DLLs) is invoked with a value indicating that the thread is detaching from the DLL.

If the thread is the last thread in the process when this function is called, the thread's process is also terminated.

The state of the thread object becomes signaled, releasing any other threads that had been waiting for the thread to terminate. The thread's termination status changes from STILL_ACTIVE to the value of the dwExitCode parameter.

Terminating a thread does not necessarily remove the thread object from the operating system. A thread object is deleted when the last handle to the thread is closed.

The ExitProcess, ExitThread, CreateThread, CreateRemoteThread functions, and a process that is starting (as the result of a CreateProcess call) are serialized between each other within a process. Only one of these events can happen in an address space at a time. This means the following restrictions hold:

  • During process startup and DLL initialization routines, new threads can be created, but they do not begin execution until DLL initialization is done for the process.
  • Only one thread in a process can be in a DLL initialization or detach routine at a time.
  • ExitProcess does not return until no threads are in their DLL initialization or detach routines.
A thread in an executable that is linked to the static C run-time library (CRT) should use _beginthread and _endthread for thread management rather than CreateThread and ExitThread. Failure to do so results in small memory leaks when the thread calls ExitThread. Another work around is to link the executable to the CRT in a DLL instead of the static CRT. Note that this memory leak only occurs from a DLL if the DLL is linked to the static CRT and a thread calls the DisableThreadLibraryCalls function. Otherwise, it is safe to call CreateThread and ExitThread from a thread in a DLL that links to the static CRT.

Use the GetExitCodeThread function to retrieve a thread's exit code.

Windows Phone 8.1: This function is supported for Windows Phone Store apps on Windows Phone 8.1 and later.

Windows 8.1 and Windows Server 2012 R2: This function is supported for Windows Store apps on Windows 8.1, Windows Server 2012 R2, and later.


For an example, see Using Event Objects.


Requirement Value
Minimum supported client Windows XP [desktop apps | UWP apps]
Minimum supported server Windows Server 2003 [desktop apps | UWP apps]
Target Platform Windows
Header processthreadsapi.h (include Windows.h on Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008 Windows Server 2008 R2)
Library Kernel32.lib; WindowsPhoneCore.lib on Windows Phone 8.1
DLL Kernel32.dll; KernelBase.dll on Windows Phone 8.1

See also








Process and Thread Functions