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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
* GC related routines
*
*/
#include <windows.h>
#include "primpl.h"
PRWord* _MD_HomeGCRegisters(PRThread* t, int isCurrent, int* np) {
#if defined(_X86_)
CONTEXT context;
context.ContextFlags = CONTEXT_INTEGER;
if (_PR_IS_NATIVE_THREAD(t)) {
context.ContextFlags |= CONTEXT_CONTROL;
if (GetThreadContext(t->md.handle, &context)) {
t->md.gcContext[0] = context.Eax;
t->md.gcContext[1] = context.Ebx;
t->md.gcContext[2] = context.Ecx;
t->md.gcContext[3] = context.Edx;
t->md.gcContext[4] = context.Esi;
t->md.gcContext[5] = context.Edi;
t->md.gcContext[6] = context.Esp;
t->md.gcContext[7] = context.Ebp;
*np = PR_NUM_GCREGS;
} else {
PR_ASSERT(0); /* XXX */
}
} else {
/* WARNING WARNING WARNING WARNING WARNING WARNING WARNING
*
* This code is extremely machine dependant and completely
* undocumented by MS. Its only known to work experimentally.
* Ready for a walk on the wild * side?
*
* WARNING WARNING WARNING WARNING WARNING WARNING WARNING */
# if !defined WIN95 // Win95 does not have fibers
int* fiberData = t->md.fiber_id;
/* I found these offsets by disassembling SwitchToFiber().
* Are your palms sweating yet?
*/
/*
** EAX is on the stack (ESP+0)
** EDX is on the stack (ESP+4)
** ECX is on the stack (ESP+8)
*/
t->md.gcContext[0] = 0; /* context.Eax */
t->md.gcContext[1] = fiberData[0x2e]; /* context.Ebx */
t->md.gcContext[2] = 0; /* context.Ecx */
t->md.gcContext[3] = 0; /* context.Edx */
t->md.gcContext[4] = fiberData[0x2d]; /* context.Esi */
t->md.gcContext[5] = fiberData[0x2c]; /* context.Edi */
t->md.gcContext[6] = fiberData[0x36]; /* context.Esp */
t->md.gcContext[7] = fiberData[0x32]; /* context.Ebp */
*np = PR_NUM_GCREGS;
# endif
}
return (PRWord*)&t->md.gcContext;
#else
PR_NOT_REACHED("not implemented");
return NULL;
#endif /* defined(_X86_) */
}
/* This function is not used right now, but is left as a reference.
* If you ever need to get the fiberID from the currently running fiber,
* this is it.
*/
void* GetMyFiberID() {
#if defined(_X86_) && !defined(__MINGW32__)
void* fiberData;
/* A pointer to our tib entry is found at FS:[18]
* At offset 10h is the fiberData pointer. The context of the
* fiber is stored in there.
*/
__asm {
mov EDX, FS:[18h]
mov EAX, DWORD PTR [EDX+10h]
mov [fiberData], EAX
}
return fiberData;
#else
PR_NOT_REACHED("not implemented");
return NULL;
#endif /* defined(_X86_) */
}