view src/thread/os2/SDL_systhread.c @ 2752:edd2839b36f7

http://sources.redhat.com/ml/newlib/2002/msg00230.html Stephen L Moshier wrote: > > pow(x,y) returns 0 when x is very close to -1.0 and y is very large. > The following test program prints > > pow(1.0000000000000002e+00 4.5035996273704970e+15) = 2.7182818284590455e+00 > pow(-1.0000000000000002e+00 4.5035996273704970e+15) =0.0000000000000000e+00 > pow(9.9999999999999978e-01 4.5035996273704970e+15) = 3.6787944117144222e-01 > pow(-9.9999999999999978e-01 4.5035996273704970e+15) = 0.0000000000000000e+00 > > which is incorrect for the negative arguments raised to an odd integer > power. > > ----- > double pow (double, double); > > int > main () > { > double x, y, z; > > x = 1.0 + pow (2.0, -52.0); > y = 1.0 + pow (2.0, 52.0); > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = -x; > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = 1.0 - pow (2.0, -52.0); > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = -x; > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > } > ----- > > Here is a patch for newlib/libm/math/epow.c: Patch checked in and duplicated for ef_pow.c. Thanks. -- Jeff J.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 15 Sep 2008 04:31:30 +0000
parents c121d94672cb
children 4436464c4f51
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* OS/2 thread management routines for SDL */

#include <process.h>
#define INCL_DOSERRORS
#define INCL_DOSPROCESS
#include <os2.h>

#include "SDL_thread.h"
#include "../SDL_systhread.h"
#include "../SDL_thread_c.h"

typedef struct ThreadStartParms
{
    void *args;
    pfnSDL_CurrentEndThread pfnCurrentEndThread;
} tThreadStartParms, *pThreadStartParms;

static void
threadfunc(void *pparm)
{
    pThreadStartParms pThreadParms = pparm;
    pfnSDL_CurrentEndThread pfnCurrentEndThread = NULL;

    // Call the thread function!
    SDL_RunThread(pThreadParms->args);

    // Get the current endthread we have to use!
    if (pThreadParms) {
        pfnCurrentEndThread = pThreadParms->pfnCurrentEndThread;
        SDL_free(pThreadParms);
    }
    // Call endthread!
    if (pfnCurrentEndThread)
        (*pfnCurrentEndThread) ();
}

int
SDL_SYS_CreateThread(SDL_Thread * thread, void *args,
                     pfnSDL_CurrentBeginThread pfnBeginThread,
                     pfnSDL_CurrentEndThread pfnEndThread)
{
    pThreadStartParms pThreadParms = SDL_malloc(sizeof(tThreadStartParms));
    if (!pThreadParms) {
        SDL_SetError("Not enough memory to create thread");
        return (-1);
    }
    // Save the function which we will have to call to clear the RTL of calling app!
    pThreadParms->pfnCurrentEndThread = pfnEndThread;
    // Also save the real parameters we have to pass to thread function
    pThreadParms->args = args;
    // Start the thread using the runtime library of calling app!
    thread->threadid = thread->handle =
        (*pfnBeginThread) (threadfunc, NULL, 512 * 1024, pThreadParms);
    if ((int) thread->threadid <= 0) {
        SDL_SetError("Not enough resources to create thread");
        return (-1);
    }
    return (0);
}

void
SDL_SYS_SetupThread(void)
{
    return;
}

DECLSPEC Uint32 SDLCALL
SDL_ThreadID(void)
{
    PTIB tib;
    DosGetInfoBlocks(&tib, NULL);
    return ((Uint32) (tib->tib_ptib2->tib2_ultid));
}

void
SDL_SYS_WaitThread(SDL_Thread * thread)
{
    TID tid = thread->handle;
    DosWaitThread(&tid, DCWW_WAIT);
}

/* WARNING: This function is really a last resort.
 * Threads should be signaled and then exit by themselves.
 * TerminateThread() doesn't perform stack and DLL cleanup.
 */
void
SDL_SYS_KillThread(SDL_Thread * thread)
{
    DosKillThread(thread->handle);
}

/* vi: set ts=4 sw=4 expandtab: */