replacements.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2006 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
/* define IN_REPLACEMENTS_C before include replacements.h */
#define IN_REPLACEMENTS_C
#include "replacements.h"
 
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
 
/*
 * clear_malloc
 *
 * will alloc memory and clear it
 */
void *clear_malloc(size_t size)
{
    void *t = malloc(size);
    if (t)
        memset(t, 0x00, size);
    return t;
}
 
void *fill_malloc(size_t size)
{
    void *t = malloc(size);
    if (t) {
        /* We want to initialize memory to some known bad state.
         * 0 and 0xff yields 0 and -1 as integers, which often
         * have meaningful values. 0x5555... is not often a valid
         * integer and is quite easily spotted in the debugger
         * also it is almost certainly an invalid address */
        memset(t, 0x55, size);
    }
    return t;
}
 
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
 
#ifdef _WIN32
#include <io.h>
#include <winsock2.h>
#endif
 
#ifndef HAVE_STRNLEN
size_t strnlen(const char *s, size_t maxlen)
{
    const char *end = (const char *)memchr(s, '\0', maxlen);
    return end ? (size_t) (end - s) : maxlen;
}
#endif
 
#ifndef HAVE_STRNDUP
char *strndup(const char *s, size_t n)
{
    size_t len = strnlen(s, n);
    char *new = malloc(len + 1);
 
    if (!new)
        return NULL;
 
    new[len] = '\0';
    return (char *) memcpy(new, s, len);
}
#endif
 
#ifdef _WIN32
 
static bool safe_fd_isset(int fd, fd_set *set)
{
    return set && OCD_FD_ISSET(fd, set);
}
 
int win_select(int max_fd, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *tv)
{
    DWORD ms_total, limit;
    HANDLE handles[MAXIMUM_WAIT_OBJECTS];
    int handle_slot_to_fd[MAXIMUM_WAIT_OBJECTS];
    int n_handles = 0, i;
    fd_set sock_read, sock_write, sock_except;
    fd_set aread, awrite, aexcept;
    int sock_max_fd = -1;
    struct timeval tvslice;
    int retcode;
 
    /* calculate how long we need to wait in milliseconds */
    if (!tv)
        ms_total = INFINITE;
    else {
        ms_total = tv->tv_sec * 1000;
        ms_total += tv->tv_usec / 1000;
    }
 
    FD_ZERO(&sock_read);
    FD_ZERO(&sock_write);
    FD_ZERO(&sock_except);
 
    /* On Windows, if all provided sets are empty/NULL an error code of -1 is returned
     * and WSAGetLastError() returns WSAEINVAL instead of delaying.
     * We check for this case, delay and return 0 instead of calling select(). */
    if (rfds && rfds->fd_count == 0)
        rfds = NULL;
    if (wfds && wfds->fd_count == 0)
        wfds = NULL;
    if (efds && efds->fd_count == 0)
        efds = NULL;
    if (!rfds && !wfds && !efds && tv) {
        sleep(tv->tv_sec);
        usleep(tv->tv_usec);
        return 0;
    }
 
    /* build an array of handles for non-sockets */
    for (i = 0; i < max_fd; i++) {
        if (safe_fd_isset(i, rfds) || safe_fd_isset(i, wfds) || safe_fd_isset(i, efds)) {
            intptr_t handle = (intptr_t) _get_osfhandle(i);
            handles[n_handles] = (HANDLE)handle;
            if (handles[n_handles] == INVALID_HANDLE_VALUE) {
                /* socket */
                if (safe_fd_isset(i, rfds))
                    OCD_FD_SET(i, &sock_read);
                if (safe_fd_isset(i, wfds))
                    OCD_FD_SET(i, &sock_write);
                if (safe_fd_isset(i, efds))
                    OCD_FD_SET(i, &sock_except);
                if (i > sock_max_fd)
                    sock_max_fd = i;
            } else {
                handle_slot_to_fd[n_handles] = i;
                n_handles++;
            }
        }
    }
 
    if (n_handles == 0) {
        /* plain sockets only - let winsock handle the whole thing */
        return select(max_fd, rfds, wfds, efds, tv);
    }
 
    /* mixture of handles and sockets; lets multiplex between
     * winsock and waiting on the handles */
 
    FD_ZERO(&aread);
    FD_ZERO(&awrite);
    FD_ZERO(&aexcept);
 
    limit = GetTickCount() + ms_total;
    do {
        retcode = 0;
 
        if (sock_max_fd >= 0) {
            /* overwrite the zero'd sets here; the select call
             * will clear those that are not active */
            aread = sock_read;
            awrite = sock_write;
            aexcept = sock_except;
 
            tvslice.tv_sec = 0;
            tvslice.tv_usec = 1000;
 
            retcode = select(sock_max_fd + 1, &aread, &awrite, &aexcept, &tvslice);
        }
 
        if (n_handles > 0) {
            /* check handles */
            DWORD wret;
 
            wret = MsgWaitForMultipleObjects(n_handles,
                    handles,
                    FALSE,
                    retcode > 0 ? 0 : 1,
                    QS_ALLEVENTS);
 
            if (wret == WAIT_TIMEOUT) {
                /* set retcode to 0; this is the default.
                 * select() may have set it to something else,
                 * in which case we leave it alone, so this branch
                 * does nothing */
                ;
            } else if (wret == WAIT_FAILED) {
                if (retcode == 0)
                    retcode = -1;
            } else {
                if (retcode < 0)
                    retcode = 0;
                for (i = 0; i < n_handles; i++) {
                    if (WaitForSingleObject(handles[i], 0) == WAIT_OBJECT_0) {
                        if (safe_fd_isset(handle_slot_to_fd[i], rfds)) {
                            DWORD bytes;
                            intptr_t handle = (intptr_t) _get_osfhandle(
                                    handle_slot_to_fd[i]);
 
                            if (PeekNamedPipe((HANDLE)handle, NULL, 0,
                                    NULL, &bytes, NULL)) {
                                /* check to see if gdb pipe has data available */
                                if (bytes) {
                                    OCD_FD_SET(handle_slot_to_fd[i], &aread);
                                    retcode++;
                                }
                            } else {
                                OCD_FD_SET(handle_slot_to_fd[i], &aread);
                                retcode++;
                            }
                        }
                        if (safe_fd_isset(handle_slot_to_fd[i], wfds)) {
                            OCD_FD_SET(handle_slot_to_fd[i], &awrite);
                            retcode++;
                        }
                        if (safe_fd_isset(handle_slot_to_fd[i], efds)) {
                            OCD_FD_SET(handle_slot_to_fd[i], &aexcept);
                            retcode++;
                        }
                    }
                }
            }
        }
    } while (retcode == 0 && (ms_total == INFINITE || GetTickCount() < limit));
 
    if (rfds)
        *rfds = aread;
    if (wfds)
        *wfds = awrite;
    if (efds)
        *efds = aexcept;
 
    return retcode;
}
#endif