DisableThreadLibraryCalls

Overview

Group

Quick Info

Windows NT
Yes
Win95
Yes
Win32s
Yes
Import Library
kernel32.lib
Header File
winbase.h
Unicode
No
Platform Notes
None

The DisableThreadLibraryCalls function disables the DLL_THREAD_ATTACH and DLL_THREAD_DETACH notifications for the dynamic-link library (DLL) specified by hLibModule. This can reduce the size of the working code set for some applications.

BOOL DisableThreadLibraryCalls(

HMODULE hLibModule	// dynamic-link library for which calls are to be disabled
);

Parameters
hLibModule
Specifies the dynamic-link library module for which the DLL_THREAD_ATTACH and DLL_THREAD_DETACH notifications are to be disabled.

Return Values
If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. The DisableThreadLibraryCalls function fails if the DLL specified by hLibModule has active static thread local storage, or if hLibModule is an invalid module handle. To get extended error information, call GetLastError.

Remarks
The DisableThreadLibraryCalls function lets a DLL disable the DLL_THREAD_ATTACH and DLL_THREAD_DETACH notification calls. This can be a useful optimization for multithreaded applications that have many DLLs, frequently create and delete threads, and whose DLLs do not need these thread-level notifications of attachment/detachment. A remote procedure call (RPC) server application is an example of such an application. In these sorts of applications, DLL initialization routines often remain in memory to service DLL_THREAD_ATTACH and DLL_THREAD_DETACH notifications. By disabling the notifications, the DLL initialization code is not paged in because a thread is created or deleted, thus reducing the size of the application's working code set. To implement the optimization, modify a DLL's DLL_PROCESS_ATTACH code to call DisableThreadLibraryCalls.