mirror of
https://github.com/python/cpython.git
synced 2024-11-30 05:15:14 +08:00
9844a1ffc3
svn+ssh://pythondev@svn.python.org/python/trunk ........ r69038 | mark.hammond | 2009-01-28 10:12:23 +1100 (Wed, 28 Jan 2009) | 3 lines On Windows, use the Python 'Activation Context' when loading extensions to avoid problems loading the CRT from a private assembly. Via bug 4566. ........
107 lines
3.8 KiB
C
107 lines
3.8 KiB
C
/*
|
|
|
|
Entry point for the Windows NT DLL.
|
|
|
|
About the only reason for having this, is so initall() can automatically
|
|
be called, removing that burden (and possible source of frustration if
|
|
forgotten) from the programmer.
|
|
|
|
*/
|
|
|
|
#include "Python.h"
|
|
#include "windows.h"
|
|
|
|
#ifdef Py_ENABLE_SHARED
|
|
char dllVersionBuffer[16] = ""; // a private buffer
|
|
|
|
// Python Globals
|
|
HMODULE PyWin_DLLhModule = NULL;
|
|
const char *PyWin_DLLVersionString = dllVersionBuffer;
|
|
|
|
// Windows "Activation Context" work:
|
|
// Our .pyd extension modules are generally built without a manifest (ie,
|
|
// those included with Python and those built with a default distutils.
|
|
// This requires we perform some "activation context" magic when loading our
|
|
// extensions. In summary:
|
|
// * As our DLL loads we save the context being used.
|
|
// * Before loading our extensions we re-activate our saved context.
|
|
// * After extension load is complete we restore the old context.
|
|
// As an added complication, this magic only works on XP or later - we simply
|
|
// use the existence (or not) of the relevant function pointers from kernel32.
|
|
// See bug 4566 (http://python.org/sf/4566) for more details.
|
|
|
|
typedef BOOL (WINAPI * PFN_GETCURRENTACTCTX)(HANDLE *);
|
|
typedef BOOL (WINAPI * PFN_ACTIVATEACTCTX)(HANDLE, ULONG_PTR *);
|
|
typedef BOOL (WINAPI * PFN_DEACTIVATEACTCTX)(DWORD, ULONG_PTR);
|
|
typedef BOOL (WINAPI * PFN_ADDREFACTCTX)(HANDLE);
|
|
typedef BOOL (WINAPI * PFN_RELEASEACTCTX)(HANDLE);
|
|
|
|
// locals and function pointers for this activation context magic.
|
|
static HANDLE PyWin_DLLhActivationContext = NULL; // one day it might be public
|
|
static PFN_GETCURRENTACTCTX pfnGetCurrentActCtx = NULL;
|
|
static PFN_ACTIVATEACTCTX pfnActivateActCtx = NULL;
|
|
static PFN_DEACTIVATEACTCTX pfnDeactivateActCtx = NULL;
|
|
static PFN_ADDREFACTCTX pfnAddRefActCtx = NULL;
|
|
static PFN_RELEASEACTCTX pfnReleaseActCtx = NULL;
|
|
|
|
void _LoadActCtxPointers()
|
|
{
|
|
HINSTANCE hKernel32 = GetModuleHandleW(L"kernel32.dll");
|
|
if (hKernel32)
|
|
pfnGetCurrentActCtx = (PFN_GETCURRENTACTCTX) GetProcAddress(hKernel32, "GetCurrentActCtx");
|
|
// If we can't load GetCurrentActCtx (ie, pre XP) , don't bother with the rest.
|
|
if (pfnGetCurrentActCtx) {
|
|
pfnActivateActCtx = (PFN_ACTIVATEACTCTX) GetProcAddress(hKernel32, "ActivateActCtx");
|
|
pfnDeactivateActCtx = (PFN_DEACTIVATEACTCTX) GetProcAddress(hKernel32, "DeactivateActCtx");
|
|
pfnAddRefActCtx = (PFN_ADDREFACTCTX) GetProcAddress(hKernel32, "AddRefActCtx");
|
|
pfnReleaseActCtx = (PFN_RELEASEACTCTX) GetProcAddress(hKernel32, "ReleaseActCtx");
|
|
}
|
|
}
|
|
|
|
ULONG_PTR _Py_ActivateActCtx()
|
|
{
|
|
ULONG_PTR ret = 0;
|
|
if (PyWin_DLLhActivationContext && pfnActivateActCtx)
|
|
if (!(*pfnActivateActCtx)(PyWin_DLLhActivationContext, &ret)) {
|
|
OutputDebugString("Python failed to activate the activation context before loading a DLL\n");
|
|
ret = 0; // no promise the failing function didn't change it!
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void _Py_DeactivateActCtx(ULONG_PTR cookie)
|
|
{
|
|
if (cookie && pfnDeactivateActCtx)
|
|
if (!(*pfnDeactivateActCtx)(0, cookie))
|
|
OutputDebugString("Python failed to de-activate the activation context\n");
|
|
}
|
|
|
|
BOOL WINAPI DllMain (HANDLE hInst,
|
|
ULONG ul_reason_for_call,
|
|
LPVOID lpReserved)
|
|
{
|
|
switch (ul_reason_for_call)
|
|
{
|
|
case DLL_PROCESS_ATTACH:
|
|
PyWin_DLLhModule = hInst;
|
|
// 1000 is a magic number I picked out of the air. Could do with a #define, I spose...
|
|
LoadString(hInst, 1000, dllVersionBuffer, sizeof(dllVersionBuffer));
|
|
|
|
// and capture our activation context for use when loading extensions.
|
|
_LoadActCtxPointers();
|
|
if (pfnGetCurrentActCtx && pfnAddRefActCtx)
|
|
if ((*pfnGetCurrentActCtx)(&PyWin_DLLhActivationContext))
|
|
if (!(*pfnAddRefActCtx)(PyWin_DLLhActivationContext))
|
|
OutputDebugString("Python failed to load the default activation context\n");
|
|
break;
|
|
|
|
case DLL_PROCESS_DETACH:
|
|
if (pfnReleaseActCtx)
|
|
(*pfnReleaseActCtx)(PyWin_DLLhActivationContext);
|
|
break;
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
#endif /* Py_ENABLE_SHARED */
|