xpmgr/BuildTools/Include/aux_ulib.h

141 lines
3.6 KiB
C

/*++
Copyright (c) 2004 Microsoft Corporation
Module Name:
aux_ulib.h
Abstract:
User mode shim to access system functionality that is not properly exposed
to applications in currently shipping operating systems.
--*/
#ifndef _AUX_SHLD_LIB_H
#define _AUX_SHLD_LIB_H
#include <windows.h>
#ifdef __cplusplus
extern "C" {
#endif
/*++
Routine Description:
This routine must be successfully called by an application before any
other routine in the library may be called. It serves to initialize any global
state that may be required by other routines in the file.
It is safe to call this routine in a multi-threaded environment.
Arguments:
None.
Return Value:
Boolean status. Error code available via GetLastError ().
--*/
BOOL
WINAPI
AuxUlibInitialize (
VOID
);
/*++
Routine Description:
This routine is used to set the current file system cache working set size. It
requires that the caller has enabled the SE_INCREASE_QUOTA_PRIVILEGE
in the currently active token prior to invoking this routine.
This API is supported on Windows 2000 and later.
Arguments:
MinimumFileCacheSize - The minimum file cache size. Use (SIZE_T)-1 if
the file cache is being flushed.
MaximumFileCacheSize - The maximum file cache size. Use (SIZE_T)-1
if the file cache is being flushed.
Flags - Flags relevant to the file cache size adjustment. Currently this must
be zero.
Return Value:
Boolean status. Error code available via GetLastError (). If the routine is
invoked prior to invoking the initialization routine, the returned error code
will be ERROR_INVALID_FUNCTION.
--*/
BOOL
WINAPI
AuxUlibSetSystemFileCacheSize (
IN SIZE_T MinimumFileCacheSize,
IN SIZE_T MaximumFileCacheSize,
IN DWORD Flags
);
/*++
Routine Description:
This routine is used to determine whether or not the caller is executing
code while holding a system synchronization primitive. Such a situation
can arise when the OS temporarily calls into user-specified code as part
of the DLL load procedure.
A caller can benefit from this information by avoiding operations that
could potentially lead to deadlocks, e.g., acquiring a process private lock.
For example, consider the following case:
Thread A runs the THREAD_ATTACH routine for DLL X. This routine
is invoked with OS DLL synchronization held. Suppose further that
as part of this routine Thread A acquires some lock in DLL X (Lx).
Thread B runs some code in DLL X that, while holding Lx, calls the OS
library loader to, e.g. GetModuleHandle. As this routine acquires
OS DLL synchronization, Thread B will deadlock with Thread A.
This is an inherent limitation in the design of the OS loader as it
performs such callouts as THREAD_ATTACH while holding loader
synchronization. It can be partially ameliorated if Thread A detects
that it is running with DLL synchronization held and only try-acquires
other locks (such as Lx) that it may wish to take
Arguments:
SynchronizationHeld - Boolean value which indicates whether or not
synchronization is held.
Return Value:
Boolean status. Error code available via GetLastError (). If the routine is
invoked prior to invoking the initialization routine, the returned error code
will be ERROR_INVALID_FUNCTION.
--*/
BOOL
WINAPI
AuxUlibIsDLLSynchronizationHeld (
OUT PBOOL SynchronizationHeld
);
#ifdef __cplusplus
}
#endif
#endif // _AUX_SHLD_LIB_H