diff options
Diffstat (limited to 'PC/dl_nt.c')
| -rw-r--r-- | PC/dl_nt.c | 68 |
1 files changed, 67 insertions, 1 deletions
diff --git a/PC/dl_nt.c b/PC/dl_nt.c index e143c780ac..f8af8026f4 100644 --- a/PC/dl_nt.c +++ b/PC/dl_nt.c @@ -18,6 +18,63 @@ char dllVersionBuffer[16] = ""; // a private buffer 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, @@ -29,9 +86,18 @@ BOOL WINAPI DllMain (HANDLE hInst, 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)); - //initall(); + + // 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; |