nss-3.41/nspr/pr/src/md/os2/os2gc.c

/* -*- 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
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * GC related routines
 *
 */
#include "primpl.h"

PRWord *_MD_HomeGCRegisters(PRThread *t, int isCurrent, int *np) 
{
    CONTEXTRECORD context;
    context.ContextFlags = CONTEXT_INTEGER;

    if (_PR_IS_NATIVE_THREAD(t)) {
        context.ContextFlags |= CONTEXT_CONTROL;
        if (QueryThreadContext(t->md.handle, CONTEXT_CONTROL, &context)) {
            t->md.gcContext[0] = context.ctx_RegEax;
            t->md.gcContext[1] = context.ctx_RegEbx;
            t->md.gcContext[2] = context.ctx_RegEcx;
            t->md.gcContext[3] = context.ctx_RegEdx;
            t->md.gcContext[4] = context.ctx_RegEsi;
            t->md.gcContext[5] = context.ctx_RegEdi;
            t->md.gcContext[6] = context.ctx_RegEsp;
            t->md.gcContext[7] = context.ctx_RegEbp;
            *np = PR_NUM_GCREGS;
        } else {
            PR_ASSERT(0);/* XXX */
        }
    }
    return (PRWord *)&t->md.gcContext;
}

/* 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()
{
    void *fiberData = 0;

    /* 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.  
     */
#ifdef HAVE_ASM
    __asm {
        mov    EDX, FS:[18h]
        mov    EAX, DWORD PTR [EDX+10h]
        mov    [fiberData], EAX
    }
#endif
  
    return fiberData;
}