misc/port.c

   1 /*
   2  * Misc. functions for systems that don't have them
   3  *
   4  * Copyright 1996 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8 #include <sys/types.h>
   9 #include <sys/time.h>
  10
  11 #ifndef HAVE_USLEEP
  12 #ifdef __EMX__
  13 unsigned int usleep (unsigned int useconds) { DosSleep(useconds); }
  14 #else
  15 unsigned int usleep (unsigned int useconds)
  16 {
  17     struct timeval delay;
  18
  19     delay.tv_sec = 0;
  20     delay.tv_usec = useconds;
  21
  22     select( 0, 0, 0, 0, &delay );
  23     return 0;
  24 }
  25 #endif
  26 #endif /* HAVE_USLEEP */
  27
  28 #ifndef HAVE_MEMMOVE
  29 void *memmove( void *dest, const void *src, unsigned int len )
  30 {
  31     register char *dst = dest;
  32
  33     /* Use memcpy if not overlapping */
  34     if ((dst + len <= (char *)src) || ((char *)src + len <= dst))
  35     {
  36         memcpy( dst, src, len );
  37     }
  38     /* Otherwise do it the hard way (FIXME: could do better than this) */
  39     else if (dst < src)
  40     {
  41         while (len--) *dst++ = *((char *)src)++;
  42     }
  43     else
  44     {
  45         dst += len - 1;
  46         src = (char *)src + len - 1;
  47         while (len--) *dst-- = *((char *)src)--;
  48     }
  49     return dest;
  50 }
  51 #endif  /* HAVE_MEMMOVE */
  52
  53 #ifndef HAVE_STRERROR
  54 const char *strerror( int err )
  55 {
  56     /* Let's hope we have sys_errlist then */
  57     return sys_errlist[err];
  58 }
  59 #endif  /* HAVE_STRERROR */
  60
  61 #if !defined(HAVE_CLONE) && defined(__linux__)
  62 #include <assert.h>
  63 #include <errno.h>
  64 #include <syscall.h>
  65 int clone( int (*fn)(void *), void *stack, int flags, void *arg )
  66 {
  67 #ifdef __i386__
  68     int ret;
  69     void **stack_ptr = (void **)stack;
  70     *--stack_ptr = arg;  /* Push argument on stack */
  71     *--stack_ptr = fn;   /* Push function pointer (popped into ebx) */
  72     __asm__ __volatile__( "pushl %%ebx\n\t"
  73                           "movl %2,%%ebx\n\t"
  74                           "int $0x80\n\t"
  75                           "popl %%ebx\n\t"   /* Contains fn in the child */
  76                           "testl %%eax,%%eax\n\t"
  77                           "jnz 0f\n\t"
  78                           "call *%%ebx\n\t"       /* Should never return */
  79                           "xorl %%eax,%%eax\n\t"  /* Just in case it does*/
  80                           "0:"
  81                           : "=a" (ret)
  82                           : "0" (SYS_clone), "g" (flags), "c" (stack_ptr) );
  83     assert( ret );  /* If ret is 0, we returned from the child function */
  84     if (ret > 0) return ret;
  85     errno = -ret;
  86     return -1;
  87 #else
  88     errno = EINVAL;
  89     return -1;
  90 #endif  /* __i386__ */
  91 }
  92 #endif  /* !HAVE_CLONE && __linux__ */