TerminateThread function

Terminates a thread.

Syntax

BOOL TerminateThread(
  HANDLE hThread,
  DWORD  dwExitCode
);

Parameters

hThread

A handle to the thread to be terminated.

The handle must have the THREAD_TERMINATE access right. For more information, see Thread Security and Access Rights.

dwExitCode

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

Return Value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

TerminateThread is used to cause a thread to exit. When this occurs, the target thread has no chance to execute any user-mode code. DLLs attached to the thread are not notified that the thread is terminating. The system frees the thread's initial stack.

Windows Server 2003 and Windows XP:  The target thread's initial stack is not freed, causing a resource leak.

TerminateThread is a dangerous function that should only be used in the most extreme cases. You should call TerminateThread only if you know exactly what the target thread is doing, and you control all of the code that the target thread could possibly be running at the time of the termination. For example, TerminateThread can result in the following problems:

  • If the target thread owns a critical section, the critical section will not be released.
  • If the target thread is allocating memory from the heap, the heap lock will not be released.
  • If the target thread is executing certain kernel32 calls when it is terminated, the kernel32 state for the thread's process could be inconsistent.
  • If the target thread is manipulating the global state of a shared DLL, the state of the DLL could be destroyed, affecting other users of the DLL.
A thread cannot protect itself against TerminateThread, other than by controlling access to its handles. The thread handle returned by the CreateThread and CreateProcess functions has THREAD_TERMINATE access, so any caller holding one of these handles can terminate your thread.

If the target thread is the last thread of a 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 system. A thread object is deleted when the last thread handle is closed.

Requirements

   
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header processthreadsapi.h (include Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008 Windows Server 2008 R2, Windows.h)
Library Kernel32.lib
DLL Kernel32.dll

See Also

CreateProcess

CreateThread

ExitThread

GetExitCodeThread

OpenThread

Process and Thread Functions

Terminating a Thread

Threads